KSC-2013-2831

NASA Image and Video Library

2013-06-19

VANDENBERG AIR FORCE BASE, Calif. – Technicians and engineers at Vandenberg Air Force Base in California mate the Pegasus XL rocket with the Interface Region Imaging Spectrograph, or IRIS, solar observatory to the Orbital Sciences L-1011 carrier aircraft. Scheduled for launch from Vandenberg on June 26, 2013, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun's visible surface and upper atmosphere, is where most of the sun's ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. For more information, visit http://www.nasa.gov/iris Photo credit: NASA/Randy Beaudoin

KSC-2013-2885

NASA Image and Video Library

2013-06-24

VANDENBERG AIR FORCE BASE, Calif. – At Vandenberg Air Force Base in California, mission managers participate in a pre-launch dress rehearsal in the Launch Vehicle Data Center for NASA’s Interface Region Imaging Spectrograph, or IRIS, solar observatory. Scheduled for launch from Vandenberg on June 26 aboard an Orbital Sciences Pegasus XL rocket, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region in to the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun’s visible surface and upper atmosphere, is where most of the sun’s ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth’s climate. For more information, visit http://www.nasa.gov/iris. Photo credit: NASA/Daniel Casper

KSC-2013-2830

NASA Image and Video Library

2013-06-19

VANDENBERG AIR FORCE BASE, Calif. – Technicians and engineers at Vandenberg Air Force Base in California mate the Pegasus XL rocket with the Interface Region Imaging Spectrograph, or IRIS, solar observatory to the Orbital Sciences L-1011 carrier aircraft. Scheduled for launch from Vandenberg on June 26, 2013, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun's visible surface and upper atmosphere, is where most of the sun's ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. For more information, visit http://www.nasa.gov/iris Photo credit: NASA/Randy Beaudoin

KSC-2013-2832

NASA Image and Video Library

2013-06-19

VANDENBERG AIR FORCE BASE, Calif. – Technicians and engineers at Vandenberg Air Force Base in California mate the Pegasus XL rocket with the Interface Region Imaging Spectrograph, or IRIS, solar observatory to the Orbital Sciences L-1011 carrier aircraft. Scheduled for launch from Vandenberg on June 26, 2013, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun's visible surface and upper atmosphere, is where most of the sun's ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. For more information, visit http://www.nasa.gov/iris Photo credit: NASA/Randy Beaudoin

KSC-2013-2912

NASA Image and Video Library

2013-06-25

VANDENBERG AIR FORCE BASE, Calif. – Final checkouts are being completed at Vandenberg Air Force Base in California as preparations continue for the launch from the L-1011 carrier aircraft of the Orbital Sciences Corp. Pegasus XL rocket with the Interface Region Imaging Spectrograph, or IRIS, solar observatory. Scheduled for launch from Vandenberg on June 26, 2013, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun's visible surface and upper atmosphere, is where most of the sun's ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. For more information, visit http://www.nasa.gov/iris Photo credit: NASA/ Daniel Casper

KSC-2013-2833

NASA Image and Video Library

2013-06-19

VANDENBERG AIR FORCE BASE, Calif. – Technicians and engineers at Vandenberg Air Force Base in California mate the Pegasus XL rocket with the Interface Region Imaging Spectrograph, or IRIS, solar observatory to the Orbital Sciences L-1011 carrier aircraft. Scheduled for launch from Vandenberg on June 26, 2013, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun's visible surface and upper atmosphere, is where most of the sun's ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. For more information, visit http://www.nasa.gov/iris Photo credit: NASA/Randy Beaudoin

KSC-2013-2824

NASA Image and Video Library

2013-06-19

VANDENBERG AIR FORCE BASE, Calif. – Technicians and engineers at Vandenberg Air Force Base in California mate the Pegasus XL rocket with the Interface Region Imaging Spectrograph, or IRIS, solar observatory to the Orbital Sciences L-1011 carrier aircraft. Scheduled for launch from Vandenberg on June 26, 2013, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun's visible surface and upper atmosphere, is where most of the sun's ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. For more information, visit http://www.nasa.gov/iris Photo credit: NASA/Randy Beaudoin

KSC-2013-2888

NASA Image and Video Library

2013-06-24

VANDENBERG AIR FORCE BASE, Calif. – At Vandenberg Air Force Base in California, mission managers participate in a pre-launch dress rehearsal in the Launch Vehicle Data Center for NASA’s Interface Region Imaging Spectrograph, or IRIS, solar observatory. Scheduled for launch from Vandenberg on June 26 aboard an Orbital Sciences Pegasus XL rocket, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region in to the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun’s visible surface and upper atmosphere, is where most of the sun’s ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth’s climate. For more information, visit http://www.nasa.gov/iris. Photo credit: NASA/Daniel Casper

KSC-2013-2827

NASA Image and Video Library

2013-06-19

VANDENBERG AIR FORCE BASE, Calif. – Technicians and engineers at Vandenberg Air Force Base in California mate the Pegasus XL rocket with the Interface Region Imaging Spectrograph, or IRIS, solar observatory to the Orbital Sciences L-1011 carrier aircraft. Scheduled for launch from Vandenberg on June 26, 2013, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun's visible surface and upper atmosphere, is where most of the sun's ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. For more information, visit http://www.nasa.gov/iris Photo credit: NASA/Randy Beaudoin

KSC-2013-2826

NASA Image and Video Library

2013-06-19

VANDENBERG AIR FORCE BASE, Calif. – Technicians and engineers at Vandenberg Air Force Base in California mate the Pegasus XL rocket with the Interface Region Imaging Spectrograph, or IRIS, solar observatory to the Orbital Sciences L-1011 carrier aircraft. Scheduled for launch from Vandenberg on June 26, 2013, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun's visible surface and upper atmosphere, is where most of the sun's ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. For more information, visit http://www.nasa.gov/iris Photo credit: NASA/Randy Beaudoin

KSC-2013-2887

NASA Image and Video Library

2013-06-24

VANDENBERG AIR FORCE BASE, Calif. – At Vandenberg Air Force Base in California, mission managers participate in a pre-launch dress rehearsal in the Launch Vehicle Data Center for NASA’s Interface Region Imaging Spectrograph, or IRIS, solar observatory. Scheduled for launch from Vandenberg on June 26 aboard an Orbital Sciences Pegasus XL rocket, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region in to the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun’s visible surface and upper atmosphere, is where most of the sun’s ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth’s climate. For more information, visit http://www.nasa.gov/iris. Photo credit: NASA/Daniel Casper

KSC-2013-2911

NASA Image and Video Library

2013-06-25

VANDENBERG AIR FORCE BASE, Calif. – Final checkouts are being completed at Vandenberg Air Force Base in California as preparations continue for the launch from the L-1011 carrier aircraft of the Orbital Sciences Corp. Pegasus XL rocket with the Interface Region Imaging Spectrograph, or IRIS, solar observatory. Scheduled for launch from Vandenberg on June 26, 2013, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun's visible surface and upper atmosphere, is where most of the sun's ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. For more information, visit http://www.nasa.gov/iris Photo credit: NASA/ Daniel Casper

KSC-2013-2829

NASA Image and Video Library

2013-06-19

VANDENBERG AIR FORCE BASE, Calif. – Technicians and engineers at Vandenberg Air Force Base in California mate the Pegasus XL rocket with the Interface Region Imaging Spectrograph, or IRIS, solar observatory to the Orbital Sciences L-1011 carrier aircraft. Scheduled for launch from Vandenberg on June 26, 2013, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun's visible surface and upper atmosphere, is where most of the sun's ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. For more information, visit http://www.nasa.gov/iris Photo credit: NASA/Randy Beaudoin

KSC-2013-2886

NASA Image and Video Library

2013-06-24

VANDENBERG AIR FORCE BASE, Calif. – At Vandenberg Air Force Base in California, mission managers participate in a pre-launch dress rehearsal in the Launch Vehicle Data Center for NASA’s Interface Region Imaging Spectrograph, or IRIS, solar observatory. Scheduled for launch from Vandenberg on June 26 aboard an Orbital Sciences Pegasus XL rocket, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region in to the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun’s visible surface and upper atmosphere, is where most of the sun’s ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth’s climate. For more information, visit http://www.nasa.gov/iris. Photo credit: NASA/Daniel Casper

KSC-2013-2834

NASA Image and Video Library

2013-06-19

VANDENBERG AIR FORCE BASE, Calif. – Technicians and engineers at Vandenberg Air Force Base in California mate the Pegasus XL rocket with the Interface Region Imaging Spectrograph, or IRIS, solar observatory to the Orbital Sciences L-1011 carrier aircraft. Scheduled for launch from Vandenberg on June 26, 2013, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun's visible surface and upper atmosphere, is where most of the sun's ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. For more information, visit http://www.nasa.gov/iris Photo credit: NASA/Randy Beaudoin

The search for signs of life on exoplanets at the interface of chemistry and planetary science.

PubMed

Seager, Sara; Bains, William

2015-03-01

The discovery of thousands of exoplanets in the last two decades that are so different from planets in our own solar system challenges many areas of traditional planetary science. However, ideas for how to detect signs of life in this mélange of planetary possibilities have lagged, and only in the last few years has modeling how signs of life might appear on genuinely alien worlds begun in earnest. Recent results have shown that the exciting frontier for biosignature gas ideas is not in the study of biology itself, which is inevitably rooted in Earth's geochemical and evolutionary specifics, but in the interface of chemistry and planetary physics.

KSC-2013-2909

NASA Image and Video Library

2013-06-25

VANDENBERG AIR FORCE BASE, Calif. – At Vandenberg Air Force Base in California, NASA hosted a prelaunch news conference on the Interface Region Imaging Spectrograph, or IRIS, solar observatory scheduled to launch on a Pegasus XL rocket. Participating in the news conference are George Diller, NASA Public Affairs, Geoffrey Yoder, deputy associate administrator for the Programs, Science Mission Directorate at NASA Headquarters in Washington, D.C., Tim Dunn, NASA launch director/NASA Launch Manager at the Kennedy Space Center in Florida, Bryan Baldwin, Pegasus launch vehicle program director for Orbital Sciences Corp. of Dulles, Va., Gary Kushner, IRIS project manager for Lockheed Martin's Solar and Astrophysics Laboratory in Palo Alto, Calif., and First Lt. Jennifer Kelley, launch weather officer for the U.S. Air Force 30th Operations Support Squadron at Vandenberg. Scheduled for launch from Vandenberg on June 26, 2013, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun's visible surface and upper atmosphere, is where most of the sun's ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. For more information, visit http://www.nasa.gov/iris Photo credit: NASA/ Daniel Casper

Helioviewer.org: Enhanced Solar & Heliospheric Data Visualization

NASA Astrophysics Data System (ADS)

Stys, J. E.; Ireland, J.; Hughitt, V. K.; Mueller, D.

2013-12-01

Helioviewer.org enables the simultaneous exploration of multiple heterogeneous solar data sets. In the latest iteration of this open-source web application, Hinode XRT and Yohkoh SXT join SDO, SOHO, STEREO, and PROBA2 as supported data sources. A newly enhanced user-interface expands the utility of Helioviewer.org by adding annotations backed by data from the Heliospheric Events Knowledgebase (HEK). Helioviewer.org can now overlay solar feature and event data via interactive marker pins, extended regions, data labels, and information panels. An interactive time-line provides enhanced browsing and visualization to image data set coverage and solar events. The addition of a size-of-the-Earth indicator provides a sense of the scale to solar and heliospheric features for education and public outreach purposes. Tight integration with the Virtual Solar Observatory and SDO AIA cutout service enable solar physicists to seamlessly import science data into their SSW/IDL or SunPy/Python data analysis environments.

New Tools to Search for Data in the European Space Agency's Planetary Science Archive

NASA Astrophysics Data System (ADS)

Grotheer, E.; Macfarlane, A. J.; Rios, C.; Arviset, C.; Heather, D.; Fraga, D.; Vallejo, F.; De Marchi, G.; Barbarisi, I.; Saiz, J.; Barthelemy, M.; Docasal, R.; Martinez, S.; Besse, S.; Lim, T.

2016-12-01

The European Space Agency's (ESA) Planetary Science Archive (PSA), which can be accessed at http://archives.esac.esa.int/psa, provides public access to the archived data of Europe's missions to our neighboring planets. These datasets are compliant with the Planetary Data System (PDS) standards. Recently, a new interface has been released, which includes upgrades to make PDS4 data available from newer missions such as ExoMars and BepiColombo. Additionally, the PSA development team has been working to ensure that the legacy PDS3 data will be more easily accessible via the new interface as well. In addition to a new querying interface, the new PSA also allows access via the EPN-TAP and PDAP protocols. This makes the PSA data sets compatible with other archive-related tools and projects, such as the Virtual European Solar and Planetary Access (VESPA) project for creating a virtual observatory.

Citizen CATE: Evaluating Outcomes of a Solar Eclipse Citizen Science Project

NASA Astrophysics Data System (ADS)

Penn, M. J.; Haden, C.

2017-12-01

On August 21, 2017, a total solar eclipse will be visible along a path of totality from Oregon to South Carolina. The Citizen Continental-America Telescopic Eclipse Experiment (CATE) will use scientists, students and volunteers to take images of the solar corona using 68 identical telescopes, software and instrument packages along the 2,500-mile path of totality. CATE partners include National Solar Observatory scientists, university faculty and students, high school students, and professional and amateur astronomers. NASA funded CATE educational components including training undergraduates and volunteers on solar imaging software and equipment. The National Science Foundation and corporations including DayStar, MathWorks, Celestron and ColorMaker funded equipment. Undergraduates participated in summer research experiences to build their capacity for gathering eclipse data, and subsequently trained volunteers across the U.S. Aligned to NASA education goals, CATE goals range from providing an authentic research experience for students and lifelong learners, to making state-of-the-art solar coronal observations, to increasing scientific literacy of the public. While project investigators are examining the wealth of scientific data that will come from CATE, evaluators are examining impacts on participants. Through mixed methods, evaluators are examining outcomes related to changes in volunteers' knowledge, skills and attitudes. Additionally, the study will examine how citizen science astronomy using CATE equipment will continue after the eclipse to sustain project impacts. Preliminary findings for undergraduates indicate that they are gaining knowledge and skills related to studying solar coronal phenomena, conducting rigorous scientific research, and interfacing with the public to conduct outreach. Preliminary findings for citizen scientists indicate a high level of engagement in the research, and that they are gaining new knowledge and skills related to solar science and eclipses. Volunteers also reported learning a great deal about safety while observing the Sun. This evaluation study will add to the body of knowledge about the effectiveness and utility of citizen science programs. Findings will be updated with data collected during and immediately after the eclipse events.

KSC-2013-2835

NASA Image and Video Library

2013-06-19

VANDENBERG AIR FORCE BASE, Calif. – At Vandenberg Air Force Base in California, the Pegasus XL rocket with the attached Interface Region Imaging Spectrograph IRIS solar observatory rolled out of the hangar on its transporter to the runway at Vandenberg. There, the rocket and spacecraft were mated with the Orbital Sciences L-1011 carrier aircraft. Scheduled for launch from Vandenberg on June 26, 2013, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun's visible surface and upper atmosphere, is where most of the sun's ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. For more information, visit http://www.nasa.gov/iris Photo credit: NASA/Randy Beaudoin

KSC-2013-2839

NASA Image and Video Library

2013-06-19

VANDENBERG AIR FORCE BASE, Calif. – At Vandenberg Air Force Base in California, the Pegasus XL rocket with the attached Interface Region Imaging Spectrograph IRIS solar observatory rolled out of the hangar on its transporter to the runway at Vandenberg. There, the rocket and spacecraft were mated with the Orbital Sciences L-1011 carrier aircraft. Scheduled for launch from Vandenberg on June 26, 2013, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun's visible surface and upper atmosphere, is where most of the sun's ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. For more information, visit http://www.nasa.gov/iris Photo credit: NASA/Randy Beaudoin

KSC-2013-2837

NASA Image and Video Library

2013-06-19

VANDENBERG AIR FORCE BASE, Calif. – At Vandenberg Air Force Base in California, the Pegasus XL rocket with the attached Interface Region Imaging Spectrograph IRIS solar observatory rolled out of the hangar on its transporter to the runway at Vandenberg. There, the rocket and spacecraft were mated with the Orbital Sciences L-1011 carrier aircraft. Scheduled for launch from Vandenberg on June 26, 2013, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun's visible surface and upper atmosphere, is where most of the sun's ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. For more information, visit http://www.nasa.gov/iris Photo credit: NASA/Randy Beaudoin

KSC-2013-2840

NASA Image and Video Library

2013-06-19

VANDENBERG AIR FORCE BASE, Calif. – At Vandenberg Air Force Base in California, the Pegasus XL rocket with the attached Interface Region Imaging Spectrograph IRIS solar observatory rolled out of the hangar on its transporter to the runway at Vandenberg. There, the rocket and spacecraft were mated with the Orbital Sciences L-1011 carrier aircraft. Scheduled for launch from Vandenberg on June 26, 2013, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun's visible surface and upper atmosphere, is where most of the sun's ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. For more information, visit http://www.nasa.gov/iris Photo credit: NASA/Randy Beaudoin

KSC-2013-2843

NASA Image and Video Library

2013-06-19

VANDENBERG AIR FORCE BASE, Calif. – At Vandenberg Air Force Base in California, the Pegasus XL rocket with the attached Interface Region Imaging Spectrograph IRIS solar observatory rolled out of the hangar on its transporter to the runway at Vandenberg. There, the rocket and spacecraft were mated with the Orbital Sciences L-1011 carrier aircraft. Scheduled for launch from Vandenberg on June 26, 2013, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun's visible surface and upper atmosphere, is where most of the sun's ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. For more information, visit http://www.nasa.gov/iris Photo credit: NASA/Randy Beaudoin

The search for signs of life on exoplanets at the interface of chemistry and planetary science

PubMed Central

Seager, Sara; Bains, William

2015-01-01

The discovery of thousands of exoplanets in the last two decades that are so different from planets in our own solar system challenges many areas of traditional planetary science. However, ideas for how to detect signs of life in this mélange of planetary possibilities have lagged, and only in the last few years has modeling how signs of life might appear on genuinely alien worlds begun in earnest. Recent results have shown that the exciting frontier for biosignature gas ideas is not in the study of biology itself, which is inevitably rooted in Earth’s geochemical and evolutionary specifics, but in the interface of chemistry and planetary physics. PMID:26601153

The Virtual Solar Observatory and the Heliophysics Meta-Virtual Observatory

NASA Astrophysics Data System (ADS)

Gurman, J. B.; Hourclé, J. A.; Bogart, R. S.; Tian, K.; Hill, F.; Suàrez-Sola, I.; Zarro, D. M.; Davey, A. R.; Martens, P. C.; Yoshimura, K.; Reardon, K. M.

2006-12-01

The Virtual Solar Observatory (VSO) has survived its infancy and provides metadata search and data identification for measurements from 45 instrument data sets held at 12 online archives, as well as flare and coronal mass ejection (CME) event lists. Like any toddler, the VSO is good at getting into anything and everything, and is now extending its grasp to more data sets, new missions, and new access methods using its application programming interface (API). We discuss and demonstrate recent changes, including developments for STEREO and SDO, and an IDL-callable interface for the VSO API. We urge the heliophysics community to help civilize this obstreperous youngster by providing input on ways to make the VSO even more useful for system science research in its role as part of the growing cluster of Heliophysics Virtual Observatories.

Helioviewer.org: Simple Solar and Heliospheric Data Visualization

NASA Astrophysics Data System (ADS)

Hughitt, V. K.; Ireland, J.; Mueller, D.

2011-12-01

Helioviewer.org is a free and open-source web application for exploring solar physics data in a simple and intuitive manner. Over the past several years, Helioviewer.org has enabled thousands of users from across the globe to explore the inner heliosphere, providing access to over ten million images from the SOHO, SDO, and STEREO missions. While Helioviewer.org has seen a surge in use by the public in recent months, it is still ultimately a science tool. The newest version of Helioviewer.org provides access to science-quality data for all available images through the Virtual Solar Observatory (VSO). In addition to providing a powerful platform for browsing heterogeneous sets of solar data, Helioviewer.org also seeks to be as flexible and extensible as possible, providing access to much of its functionality via a simple Application Programming Interface (API). Recently, the Helioviewer.org API was used for two such applications: a Wordpress plugin, and a Python library for solar physics data analysis (SunPy). These applications are discussed and examples of API usage are provided. Finally, Helioviewer.org is undergoing continual development, with new features being added on a regular basis. Recent updates to Helioviewer.org are discussed, along with a preview of things to come.

Study program for encapsulation materials interface for low-cost solar array

NASA Technical Reports Server (NTRS)

Kaelble, D. H.; Mansfeld, F. B.; Kendig, M.; Leung, C.

1981-01-01

The service integrity of the bonded interface in solar cell modules used in solar arrays is addressed. The development of AC impedance as a nondestructive evaluation (NDE) methodology for solar arrays is reported along with development of corrosion models and materials selection criteria for corrosion resistant interfaces.

Integrating a Data Center and Resident Archive into the Emerging Virtual Observatiry System: Practical experience and perspectives

NASA Astrophysics Data System (ADS)

Davis, A. J.; Kanekal, S. G.; Looper, M. D.; Mason, G. M.; Mewaldt, R. A.

2006-12-01

The SAMPEX Resident Archive is currently under construction, and will be co-hosted at Caltech with the ACE Science Center. With SAMPEX in low earth orbit, and ACE at L1, and a suite of instruments on each spacecraft, the combined data cover a very broad range in species, energy, location, and time. The data include solar wind, solar energetic particle, and galactic cosmic ray intensity and composition data, as well as solar wind and magnetic field parameters on a variety of time scales. We describe our recent efforts to provide enhanced access to these data via the emerging virtual observatory system, including work with the Space Physics Archive Search and Extract (SPASE) Consortium to ensure that the ACE and SAMPEX data can be adequately described using the SPASE data model, development of a SOAP web services interface between the ACE Science Center and the virtual observatories, and ideas for combining the ACE and SAMPEx data in useful ways.

Simulation of a high-efficiency silicon-based heterojunction solar cell

NASA Astrophysics Data System (ADS)

Jian, Liu; Shihua, Huang; Lü, He

2015-04-01

The basic parameters of a-Si:H/c-Si heterojunction solar cells, such as layer thickness, doping concentration, a-Si:H/c-Si interface defect density, and the work functions of the transparent conducting oxide (TCO) and back surface field (BSF) layer, are crucial factors that influence the carrier transport properties and the efficiency of the solar cells. The correlations between the carrier transport properties and these parameters and the performance of a-Si:H/c-Si heterojunction solar cells were investigated using the AFORS-HET program. Through the analysis and optimization of a TCO/n-a-Si:H/i-a-Si:H/p-c-Si/p+-a-Si:H/Ag solar cell, a photoelectric conversion efficiency of 27.07% (VOC) 749 mV, JSC: 42.86 mA/cm2, FF: 84.33%) was obtained through simulation. An in-depth understanding of the transport properties can help to improve the efficiency of a-Si:H/c-Si heterojunction solar cells, and provide useful guidance for actual heterojunction with intrinsic thin layer (HIT) solar cell manufacturing. Project supported by the National Natural Science Foundation of China (No. 61076055), the Open Project Program of Surface Physics Laboratory (National Key Laboratory) of Fudan University (No. FDS-KL2011-04), the Zhejiang Provincial Science and Technology Key Innovation Team (No. 2011R50012), and the Zhejiang Provincial Key Laboratory (No. 2013E10022).

KSC-2013-2939

NASA Image and Video Library

2013-06-27

VANDENBERG AIR FORCE BASE, Calif. – The Orbital Sciences L-1011 aircraft takes off from Vandenberg Air Force Base in California at 9:30 p.m. EDT, headed over the Pacific Ocean to release the Pegasus XL rocket carrying NASA's Interface Region Imaging Spectrograph, or IRIS, solar observatory. Release of the rocket from under the wing of the aircraft is scheduled for 10:27 p.m. EDT. IRIS will open a new window of discovery using spectrometry and imaging to trace the flow of energy and plasma through the chromospheres and transition region into the sun’s corona. The spacecraft will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. This interface region, located between the sun's visible surface and its upper atmosphere, is where most of its ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. NASA's Launch Services Program at the agency's Kennedy Space Center in Florida is managing the countdown and launch. For more information, visit http://www.nasa.gov/iris. Photo credit: NASA/Daniel Casper

Charge separation and carrier dynamics in donor-acceptor heterojunction photovoltaic systems.

PubMed

Teuscher, Joël; Brauer, Jan C; Stepanov, Andrey; Solano, Alicia; Boziki, Ariadni; Chergui, Majed; Wolf, Jean-Pierre; Rothlisberger, Ursula; Banerji, Natalie; Moser, Jacques-E

2017-11-01

Electron transfer and subsequent charge separation across donor-acceptor heterojunctions remain the most important areas of study in the field of third-generation photovoltaics. In this context, it is particularly important to unravel the dynamics of individual ultrafast processes (such as photoinduced electron transfer, carrier trapping and association, and energy transfer and relaxation), which prevail in materials and at their interfaces. In the frame of the National Center of Competence in Research "Molecular Ultrafast Science and Technology," a research instrument of the Swiss National Science Foundation, several groups active in the field of ultrafast science in Switzerland have applied a number of complementary experimental techniques and computational simulation tools to scrutinize these critical photophysical phenomena. Structural, electronic, and transport properties of the materials and the detailed mechanisms of photoinduced charge separation in dye-sensitized solar cells, conjugated polymer- and small molecule-based organic photovoltaics, and high-efficiency lead halide perovskite solar energy converters have been scrutinized. Results yielded more than thirty research articles, an overview of which is provided here.

A Data Services Upgrade for Advanced Composition Explorer (ACE) Data

NASA Astrophysics Data System (ADS)

Davis, A. J.; Hamell, G.

2008-12-01

Since early in 1998, NASA's Advanced Composition Explorer (ACE) spacecraft has provided continuous measurements of solar wind, interplanetary magnetic field, and energetic particle activity from L1, located approximately 0.01 AU sunward of Earth. The spacecraft has enough fuel to stay in orbit about L1 until ~2024. The ACE Science Center (ASC) provides access to ACE data, and performs level 1 and browse data processing for the science instruments. Thanks to a NASA Data Services Upgrade grant, we have recently retooled our legacy web interface to ACE data, enhancing data subsetting capabilities and improving online plotting options. We have also integrated a new application programming interface (API) and we are working to ensure that it will be compatible with emerging Virtual Observatory (VO) data services standards. The new API makes extensive use of metadata created using the Space Physics Archive Search and Extract (SPASE) data model. We describe these recent improvements to the ACE Science Center data services, and our plans for integrating these services into the VO system.

International Observe the Moon Night: Eight Years of Engaging Scientists, Educators, and Citizen Enthusiasts in NASA Science

NASA Astrophysics Data System (ADS)

Buxner, Sanlyn; Jones, Andrea; Bleacher, Lora; Wasser, Molly; Day, Brian; Bakerman, Maya; Shaner, Andrew; Joseph, Emily; International Observe the Moon Night Coordinating Committee

2018-01-01

International Observe the Moon Night (InOMN) is an annual worldwide event, held in the fall, that celebrates lunar and planetary science and exploration. InOMN is sponsored by NASA’s Lunar Reconnaissance Orbiter (LRO) in collaboration with NASA’s Solar System Exploration Research Virtual Institute (SSERVI), the NASA’s Heliophysics Education Consortium, CosmoQuest, Night Sky Network, and Science Festival Alliance. Other key partners include the NASA Museum Alliance, Night Sky Network, and NASA Solar System Ambassadors.In 2017 InOMN will be held on October 28th, and will engage thousands of people across the globe to observe and learn about the Moon and its connection to planetary science. This year, we have partnered with the NASA Science Mission Directorate total solar eclipse team to highlight InOMN as an opportunity to harness and sustain the interest and momentum in space science and observation following the August 21st eclipse. Since 2010, over 3,800 InOMN events have been registered engaging over 550,000 visitors worldwide. Most InOMN events are held in the United States, with strong representation from many other countries. We will present current results from the 2017 InOMN evaluation.Through InOMN, we annually provide resources such as event-specific Moon maps, presentations, advertising materials, and certificates of participation. Additionally, InOMN highlights partner resources such as online interfaces including Moon Trek (https://moontrek.jpl.nasa.gov) and CosmoQuest (https://cosmoquest.org/x/) to provide further opportunities to engage with NASA science.Learn more about InOMN at http://observethemoonnight.org.

Solar research with ALMA: Czech node of European ARC as your user-support infrastructure

NASA Astrophysics Data System (ADS)

Bárta, M.; Skokić, I.; Brajša, R.; Czech ARC Node Team

2017-08-01

ALMA (Atacama Large Millimeter/sub-millimeter Array) is by far the largest project of current ground-based observational facilities in astronomy and astrophysics. It is built and operated in the world-wide cooperation (ESO, NRAO, NAOJ) at altitude of 5000m in the desert of Atacama, Chile. Because of its unprecedented capabilities, ALMA is considered as a cutting-edge research device in astrophysics with potential for many breakthrough discoveries in the next decade and beyond. In spite it is not exclusively solar-research dedicated instrument, science observations of the Sun are now possible and has recently started in the observing Cycle 4 (2016-2017). In order to facilitate user access to this top-class, but at the same moment very complicated device to researchers lacking technical expertise, a network of three ALMA Regional Centers (ARCs) has been formed in Europe, North America, and East Asia as a user-support infrastructure and interface between the observatory and users community. After short introduction to ALMA the roles of ARCs and hint how to utilize their services will be presented, with emphasis to the specific (and in Europe unique) mission of the Czech ARC node in solar research with ALMA. Finally, peculiarities of solar observations that demanded the development of the specific Solar ALMA Observing Modes will be discussed and the results of Commissioning and Science Verification observing campaigns (solar ALMA maps) will be shown.

Interfaces of high-efficiency kesterite Cu2ZnSnS(e)4 thin film solar cells

NASA Astrophysics Data System (ADS)

Gao, Shoushuai; Jiang, Zhenwu; Wu, Li; Ao, Jianping; Zeng, Yu; Sun, Yun; Zhang, Yi

2018-01-01

Cu2ZnSnS(e)4 (CZTS(e)) solar cells have attracted much attention due to the elemental abundance and the non-toxicity. However, the record efficiency of 12.6% for Cu2ZnSn(S,Se)4 (CZTSSe) solar cells is much lower than that of Cu(In,Ga)Se2 (CIGS) solar cells. One crucial reason is the recombination at interfaces. In recent years, large amount investigations have been done to analyze the interfacial problems and improve the interfacial properties via a variety of methods. This paper gives a review of progresses on interfaces of CZTS(e) solar cells, including: (1) the band alignment optimization at buffer/CZTS(e) interface, (2) tailoring the thickness of MoS(e)2 interfacial layers between CZTS(e) absorber and Mo back contact, (3) the passivation of rear interface, (4) the passivation of front interface, and (5) the etching of secondary phases.

Prioritized System Science Targets for Heliophysics

NASA Astrophysics Data System (ADS)

Spann, J. F.; Christensen, A. B.; St Cyr, O. C.; Posner, A.; Giles, B. L.

2009-12-01

Heliophysics is a discipline that investigates the science at work from the interface of Earth and space, to the core of the Sun, and to the outer edge of our solar system. This solar-interplanetary-planetary system is vast and inherently coupled on many spatial, temporal and energy scales. The Sun’s explosive energy output creates complicated field and plasma structures that when coupled with our terrestrial magnetized space, generates an extraordinary complex environment that has practical implications for humanity as we are becoming increasingly dependent on space-based assets. This immense volume of our cosmic neighborhood is the domain of heliophysics. Understanding this domain and the dominant mechanisms that control the transfer of mass and energy requires a system approach that addresses all aspects and regions of the system. The 2009 NASA Heliophysics Roadmap presents a science-focused strategic approach to advance the goal of heliophysics: why does the Sun vary; how do the Earth and heliosphere respond; and what are the impacts on humanity? This talk will present the top 6 prioritized science targets to understand the coupled heliophysics system as presented in the 2009 NASA Heliophysics Roadmap. An exposition of each science target and how it addresses outstanding questions in heliophysics will be discussed.

Future System Science Mission Targets for Heliophysics

NASA Technical Reports Server (NTRS)

Spann, James; Christensen, Andrew B.; SaintCyr, O. C.; Giles, Barbara I.; Posner, Arik

2009-01-01

Heliophysics is a discipline that investigates the science at work from the interface of Earth and space, to the core of the Sun, and to the outer edge of our solar system. This solar-interplanetary-planetary system is vast and inherently coupled on many spatial, temporal and energy scales. The Sun's explosive energy output creates complicated field and plasma structures that when coupled without terrestrial magnetized space, generates an extraordinary complex environment that has practical implications for humanity as we are becoming increasingly dependent on space-based assets. The immense volume of our cosmic neighborhood is the domain of heliophysics. Understanding this domain and the dominant mechanisms that control the transfer of mass and energy requires a system approach that addresses all aspects and regions of the system. The 2009 NASA Heliophysics Roadmap presents a science-focused strategic approach to advance the goal of heliophysics: why does the Sun vary; how do the Earth and heliosphere respond; and what are the impacts on humanity? This talk will present the top 6 prioritized science targets to understand the coupled heliophysics system as presented in the 2009 NASA Heliophysics Roadmap. An exposition of each science target and how it addresses outstanding questions in heliophysics will be discussed.

Prioritized System Science Targets for Heliophysics

NASA Technical Reports Server (NTRS)

Spann, James Frederick; Christensen, Andrew B.; SaintCyr, Orville Chris; Posner, Arik; Giles, Barbara L.

2009-01-01

Heliophysics is a discipline that investigates the science at work from the interface of Earth and space, to the core of the Sun, and to the outer edge of our solar system. This solar-interplanetary-planetary system is vast and inherently coupled on many spatial, temporal and energy scales. The Sun's explosive energy output creates complicated field and plasma structures that when coupled with our terrestrial magnetized space, generates an extraordinary complex environment that has practical implications for humanity as we are becoming increasingly dependent on space-based assets. This immense volume of our cosmic neighborhood is the domain of heliophysics. Understanding this domain and the dominant mechanisms that control the transfer of mass and energy requires a system approach that addresses all aspects and regions of the system. The 2009 NASA Heliophysics Roadmap presents a science-focused strategic approach to advance the goal of heliophysics: why does the Sun vary; how do the Earth and heliosphere respond; and what are the impacts on humanity? This talk will present the top 6 prioritized science targets to understand the coupled heliophysics system as presented in the 2009 NASA Heliophysics Roadmap. An exposition of each science target and how it addresses outstanding questions in heliophysics will be discussed.

CATE 2016 Indonesia: Camera, Software, and User Interface

NASA Astrophysics Data System (ADS)

Kovac, S. A.; Jensen, L.; Hare, H. S.; Mitchell, A. M.; McKay, M. A.; Bosh, R.; Watson, Z.; Penn, M.

2016-12-01

The Citizen Continental-America Telescopic Eclipse (Citizen CATE) Experiment will use a fleet of 60 identical telescopes across the United States to image the inner solar corona during the 2017 total solar eclipse. For a proof of concept, five sites were hosted along the path of totality during the 2016 total solar eclipse in Indonesia. Tanjung Pandan, Belitung, Indonesia was the first site to experience totality. This site had the best seeing conditions and focus, resulting in the highest quality images. This site proved that the equipment that is going to be used is capable of recording high quality images of the solar corona. Because 60 sites will be funded, each set up needs to be cost effective. This requires us to use an inexpensive camera, which consequently has a small dynamic range. To compensate for the corona's intensity drop off factor of 1,000, images are taken at seven frames per second, at exposures 0.4ms, 1.3ms, 4.0ms, 13ms, 40ms, 130ms, and 400ms. Using MatLab software, we are able to capture a high dynamic range with an Arduino that controls the 2448 x 2048 CMOS camera. A major component of this project is to train average citizens to use the software, meaning it needs to be as user friendly as possible. The CATE team is currently working with MathWorks to create a graphic user interface (GUI) that will make data collection run smoothly. This interface will include tabs for alignment, focus, calibration data, drift data, GPS, totality, and a quick look function. This work was made possible through the National Solar Observatory Research Experiences for Undergraduates (REU) Program, which is funded by the National Science Foundation (NSF). The NSO Training for 2017 Citizen CATE Experiment, funded by NASA (NASA NNX16AB92A), also provided support for this project. The National Solar Observatory is operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the NSF.

Development of public science archive system of Subaro Telescope. 2

NASA Astrophysics Data System (ADS)

Yamamoto, Naotaka; Noda, Sachiyo; Taga, Masatoshi; Ozawa, Tomohiko; Horaguchi, Toshihiro; Okumura, Shin-Ichiro; Furusho, Reiko; Baba, Hajime; Yagi, Masafumi; Yasuda, Naoki; Takata, Tadafumi; Ichikawa, Shin-Ichi

2003-09-01

We report various improvements in a public science archive system, SMOKA (Subaru-Mitaka-Okayama-Kiso Archive system). We have developed a new interface to search observational data of minor bodies in the solar system. In addition, the other improvements (1) to search frames by specifying wavelength directly, (2) to find out calibration data set automatically, (3) to browse data on weather, humidity, and temperature, which provide information of image quality, (4) to provide quick-look images of OHS/CISCO and IRCS, and (5) to include the data from OAO HIDES (HIgh Dispersion Echelle Spectrograph), are also summarized.

Technologies and Methods Used at the Laboratory for Atmospheric and Space Physics (LASP) to Serve Solar Irradiance Data

NASA Technical Reports Server (NTRS)

Pankratz, Chris; Beland, Stephane; Craft, James; Baltzer, Thomas; Wilson, Anne; Lindholm, Doug; Snow, Martin; Woods, Thomas; Woodraska, Don

2018-01-01

The Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado in Boulder, USA operates the Solar Radiation and Climate Experiment (SORCE) NASA mission, as well as several other NASA spacecraft and instruments. Dozens of Solar Irradiance data sets are produced, managed, and disseminated to the science community. Data are made freely available to the scientific immediately after they are produced using a variety of data access interfaces, including the LASP Interactive Solar Irradiance Datacenter (LISIRD), which provides centralized access to a variety of solar irradiance data sets using both interactive and scriptable/programmatic methods. This poster highlights the key technological elements used for the NASA SORCE mission ground system to produce, manage, and disseminate data to the scientific community and facilitate long-term data stewardship. The poster presentation will convey designs, technological elements, practices and procedures, and software management processes used for SORCE and their relationship to data quality and data management standards, interoperability, NASA data policy, and community expectations.

Interoperability at ESA Heliophysics Science Archives: IVOA, HAPI and other implementations

NASA Astrophysics Data System (ADS)

Martinez-Garcia, B.; Cook, J. P.; Perez, H.; Fernandez, M.; De Teodoro, P.; Osuna, P.; Arnaud, M.; Arviset, C.

2017-12-01

The data of ESA heliophysics science missions are preserved at the ESAC Science Data Centre (ESDC). The ESDC aims for the long term preservation of those data, which includes missions such as Ulysses, Soho, Proba-2, Cluster, Double Star, and in the future, Solar Orbiter. Scientists have access to these data through web services, command line and graphical user interfaces for each of the corresponding science mission archives. The International Virtual Observatory Alliance (IVOA) provides technical standards that allow interoperability among different systems that implement them. By adopting some IVOA standards, the ESA heliophysics archives are able to share their data with those tools and services that are VO-compatible. Implementation of those standards can be found in the existing archives: Ulysses Final Archive (UFA) and Soho Science Archive (SSA). They already make use of VOTable format definition and Simple Application Messaging Protocol (SAMP). For re-engineered or new archives, the implementation of services through Table Access Protocol (TAP) or Universal Worker Service (UWS) will leverage this interoperability. This will be the case for the Proba-2 Science Archive (P2SA) and the Solar Orbiter Archive (SOAR). We present here which IVOA standards were already used by the ESA Heliophysics archives in the past and the work on-going.

Preparing NASA's Next Solar Satellite for Launch

NASA Image and Video Library

2017-12-08

Orbital Sciences team members move the second half of the payload fairing before it is placed over NASA's IRIS (Interface Region Imaging Spectrograph) spacecraft. The fairing connects to the nose of the Orbital Sciences Pegasus XL rocket that will lift the solar observatory into orbit. The work is taking place in a hangar at Vandenberg Air Force Base, where IRIS is being prepared for launch on a Pegasus XL rocket. Scheduled for launch from Vandenberg on June 26, 2013, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun's corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. High res file available here: 1.usa.gov/11yal3w Photo Credit: NASA/Tony Vauclin NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

A generic interface to reduce the efficiency-stability-cost gap of perovskite solar cells

NASA Astrophysics Data System (ADS)

Hou, Yi; Du, Xiaoyan; Scheiner, Simon; McMeekin, David P.; Wang, Zhiping; Li, Ning; Killian, Manuela S.; Chen, Haiwei; Richter, Moses; Levchuk, Ievgen; Schrenker, Nadine; Spiecker, Erdmann; Stubhan, Tobias; Luechinger, Norman A.; Hirsch, Andreas; Schmuki, Patrik; Steinrück, Hans-Peter; Fink, Rainer H.; Halik, Marcus; Snaith, Henry J.; Brabec, Christoph J.

2017-12-01

A major bottleneck delaying the further commercialization of thin-film solar cells based on hybrid organohalide lead perovskites is interface loss in state-of-the-art devices. We present a generic interface architecture that combines solution-processed, reliable, and cost-efficient hole-transporting materials without compromising efficiency, stability, or scalability of perovskite solar cells. Tantalum-doped tungsten oxide (Ta-WOx)/conjugated polymer multilayers offer a surprisingly small interface barrier and form quasi-ohmic contacts universally with various scalable conjugated polymers. In a simple device with regular planar architecture and a self-assembled monolayer, Ta-WOx-doped interface-based perovskite solar cells achieve maximum efficiencies of 21.2% and offer more than 1000 hours of light stability. By eliminating additional ionic dopants, these findings open up the entire class of organics as scalable hole-transporting materials for perovskite solar cells.

The Semantic eScience Framework

NASA Astrophysics Data System (ADS)

McGuinness, Deborah; Fox, Peter; Hendler, James

2010-05-01

The goal of this effort is to design and implement a configurable and extensible semantic eScience framework (SESF). Configuration requires research into accommodating different levels of semantic expressivity and user requirements from use cases. Extensibility is being achieved in a modular approach to the semantic encodings (i.e. ontologies) performed in community settings, i.e. an ontology framework into which specific applications all the way up to communities can extend the semantics for their needs.We report on how we are accommodating the rapid advances in semantic technologies and tools and the sustainable software path for the future (certain) technical advances. In addition to a generalization of the current data science interface, we will present plans for an upper-level interface suitable for use by clearinghouses, and/or educational portals, digital libraries, and other disciplines.SESF builds upon previous work in the Virtual Solar-Terrestrial Observatory. The VSTO utilizes leading edge knowledge representation, query and reasoning techniques to support knowledge-enhanced search, data access, integration, and manipulation. It encodes term meanings and their inter-relationships in ontologies anduses these ontologies and associated inference engines to semantically enable the data services. The Semantically-Enabled Science Data Integration (SESDI) project implemented data integration capabilities among three sub-disciplines; solar radiation, volcanic outgassing and atmospheric structure using extensions to existingmodular ontolgies and used the VSTO data framework, while adding smart faceted search and semantic data registrationtools. The Semantic Provenance Capture in Data Ingest Systems (SPCDIS) has added explanation provenance capabilities to an observational data ingest pipeline for images of the Sun providing a set of tools to answer diverseend user questions such as ``Why does this image look bad?. http://tw.rpi.edu/portal/SESF

The Semantic eScience Framework

NASA Astrophysics Data System (ADS)

Fox, P. A.; McGuinness, D. L.

2009-12-01

The goal of this effort is to design and implement a configurable and extensible semantic eScience framework (SESF). Configuration requires research into accommodating different levels of semantic expressivity and user requirements from use cases. Extensibility is being achieved in a modular approach to the semantic encodings (i.e. ontologies) performed in community settings, i.e. an ontology framework into which specific applications all the way up to communities can extend the semantics for their needs.We report on how we are accommodating the rapid advances in semantic technologies and tools and the sustainable software path for the future (certain) technical advances. In addition to a generalization of the current data science interface, we will present plans for an upper-level interface suitable for use by clearinghouses, and/or educational portals, digital libraries, and other disciplines.SESF builds upon previous work in the Virtual Solar-Terrestrial Observatory. The VSTO utilizes leading edge knowledge representation, query and reasoning techniques to support knowledge-enhanced search, data access, integration, and manipulation. It encodes term meanings and their inter-relationships in ontologies anduses these ontologies and associated inference engines to semantically enable the data services. The Semantically-Enabled Science Data Integration (SESDI) project implemented data integration capabilities among three sub-disciplines; solar radiation, volcanic outgassing and atmospheric structure using extensions to existingmodular ontolgies and used the VSTO data framework, while adding smart faceted search and semantic data registrationtools. The Semantic Provenance Capture in Data Ingest Systems (SPCDIS) has added explanation provenance capabilities to an observational data ingest pipeline for images of the Sun providing a set of tools to answer diverseend user questions such as ``Why does this image look bad?.

Graphene-Enhanced Thermal Interface Materials for Thermal Management of Solar Cells

NASA Astrophysics Data System (ADS)

Saadah, Mohammed Ahmed

The interest to photovoltaic solar cells as a source of energy for a variety of applications has been rapidly increasing in recent years. Solar cells panels that employ optical concentrators can convert more than 30% of absorbed light into electricity. Most of the remaining 70% of absorbed energy is turned into heat inside the solar cell. The increase in the photovoltaic cell temperature negatively affects its power conversion efficiency and lifetime. In this dissertation research I investigated a feasibility of using graphene fillers in thermal interface materials for improving thermal management of multi-junction concentrator solar cells. Graphene and few-layer graphene fillers, produced by a scalable environmentally-friendly liquid-phase exfoliation technique, were incorporated into conventional thermal interface materials. Characteristics of the composites have been examined with Raman spectroscopy, optical microscopy and thermal conductivity measurements. Graphene-enhanced thermal interface materials have been applied between a solar cell and heat sink to improve heat dissipation. The performance of the single and multi-junction solar cells has been tested using an industry-standard solar simulator under the light concentration of up to 2000 suns. It was found that the application of graphene-enhanced thermal interface materials allows one to reduce the solar cell temperature and increase the open-circuit voltage. We demonstrated that the use of graphene helps in recovering significant amount of the power loss due to solar cell overheating. The obtained results are important for the development of new technologies for thermal management of concentrated and multi-junction photovoltaic solar cells.

Charge separation and carrier dynamics in donor-acceptor heterojunction photovoltaic systems

PubMed Central

Teuscher, Joël; Brauer, Jan C.; Stepanov, Andrey; Solano, Alicia; Boziki, Ariadni; Chergui, Majed; Wolf, Jean-Pierre; Rothlisberger, Ursula; Banerji, Natalie; Moser, Jacques-E.

2017-01-01

Electron transfer and subsequent charge separation across donor-acceptor heterojunctions remain the most important areas of study in the field of third-generation photovoltaics. In this context, it is particularly important to unravel the dynamics of individual ultrafast processes (such as photoinduced electron transfer, carrier trapping and association, and energy transfer and relaxation), which prevail in materials and at their interfaces. In the frame of the National Center of Competence in Research “Molecular Ultrafast Science and Technology,” a research instrument of the Swiss National Science Foundation, several groups active in the field of ultrafast science in Switzerland have applied a number of complementary experimental techniques and computational simulation tools to scrutinize these critical photophysical phenomena. Structural, electronic, and transport properties of the materials and the detailed mechanisms of photoinduced charge separation in dye-sensitized solar cells, conjugated polymer- and small molecule-based organic photovoltaics, and high-efficiency lead halide perovskite solar energy converters have been scrutinized. Results yielded more than thirty research articles, an overview of which is provided here. PMID:29308415

Carrier collection losses in interface passivated amorphous silicon thin-film solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neumüller, A., E-mail: alex.neumueller@next-energy.de; Sergeev, O.; Vehse, M.

In silicon thin-film solar cells the interface between the i- and p-layer is the most critical. In the case of back diffusion of photogenerated minority carriers to the i/p-interface, recombination occurs mainly on the defect states at the interface. To suppress this effect and to reduce recombination losses, hydrogen plasma treatment (HPT) is usually applied. As an alternative to using state of the art HPT we apply an argon plasma treatment (APT) before the p-layer deposition in n-i-p solar cells. To study the effect of APT, several investigations were applied to compare the results with HPT and no plasma treatmentmore » at the interface. Carrier collection losses in resulting solar cells were examined with spectral response measurements with and without bias voltage. To investigate single layers, surface photovoltage and X-ray photoelectron spectroscopy (XPS) measurements were conducted. The results with APT at the i/p-interface show a beneficial contribution to the carrier collection compared with HPT and no plasma treatment. Therefore, it can be concluded that APT reduces the recombination centers at the interface. Further, we demonstrate that carrier collection losses of thin-film solar cells are significantly lower with APT.« less

First Prototype of a Web Map Interface for ESA's Planetary Science Archive (PSA)

NASA Astrophysics Data System (ADS)

Manaud, N.; Gonzalez, J.

2014-04-01

We present a first prototype of a Web Map Interface that will serve as a proof of concept and design for ESA's future fully web-based Planetary Science Archive (PSA) User Interface. The PSA is ESA's planetary science archiving authority and central repository for all scientific and engineering data returned by ESA's Solar System missions [1]. All data are compliant with NASA's Planetary Data System (PDS) Standards and are accessible through several interfaces [2]: in addition to serving all public data via FTP and the Planetary Data Access Protocol (PDAP), a Java-based User Interface provides advanced search, preview, download, notification and delivery-basket functionality. It allows the user to query and visualise instrument observations footprints using a map-based interface (currently only available for Mars Express HRSC and OMEGA instruments). During the last decade, the planetary mapping science community has increasingly been adopting Geographic Information System (GIS) tools and standards, originally developed for and used in Earth science. There is an ongoing effort to produce and share cartographic products through Open Geospatial Consortium (OGC) Web Services, or as standalone data sets, so that they can be readily used in existing GIS applications [3,4,5]. Previous studies conducted at ESAC [6,7] have helped identify the needs of Planetary GIS users, and define key areas of improvement for the future Web PSA User Interface. Its web map interface shall will provide access to the full geospatial content of the PSA, including (1) observation geometry footprints of all remote sensing instruments, and (2) all georeferenced cartographic products, such as HRSC map-projected data or OMEGA global maps from Mars Express. It shall aim to provide a rich user experience for search and visualisation of this content using modern and interactive web mapping technology. A comprehensive set of built-in context maps from external sources, such as MOLA topography, TES infrared maps or planetary surface nomenclature, provided in both simple cylindrical and polar stereographic projections, shall enhance this user experience. In addition, users should be able to import and export data in commonly used open- GIS formats. It is also intended to serve all PSA geospatial data through OGC-compliant Web Services so that they can be captured, visualised and analysed directly from GIS software, along with data from other sources. The following figure illustrates how the PSA web map interface and services shall fit in a typical Planetary GIS user working environment.

A novel strategy to increase separated electron-hole dipoles in commercial Si based solar panel to assist photovoltaic effect

NASA Astrophysics Data System (ADS)

Feng, Yefeng; He, Cheng-En; Xu, Zhichao; Hu, Jianbing; Peng, Cheng

2018-01-01

Interface induced polarization has been found to have a significant impact on dielectric properties of 2-2 type polymer composites bearing Si based semi-conducting ceramic sheets. Inherent overall polarity of polymer layers in 2-2 composites has been verified to be closely connected with interface effect and achieved permittivity in composites. In present work, conducting performances of monocrystalline Si sheets coated by varied high polarity material layers were deeply researched. The positive results inspired us to propose a novel strategy to improve separated electron-hole dipoles in commercial Si based solar cell panel for assisting photovoltaic effect, based on strong interface induced polarization. Conducting features of solar panels coated by two different high polarity polymer layers were detected to be greatly elevated compared with solar panel standalone, thanks to interface induced polarization between panel and polymer. Polymer coating with higher polarity would lead to more separated electron-hole dipole pairs in solar panel contributing to higher conductivity of panel. Valid synergy of interface effect and photovoltaic effect was based on their unidirectional traits of electron transfer. Dielectric properties of solar panels in composites further confirmed that strategy. This work might provide a facile route to prepare promising Si based solar panels with higher photoelectric conversion efficiency by enhancing interface induced polarization between panel and polymer coating.

Materials interface engineering for solution-processed photovoltaics.

PubMed

Graetzel, Michael; Janssen, René A J; Mitzi, David B; Sargent, Edward H

2012-08-16

Advances in solar photovoltaics are urgently needed to increase the performance and reduce the cost of harvesting solar power. Solution-processed photovoltaics are cost-effective to manufacture and offer the potential for physical flexibility. Rapid progress in their development has increased their solar-power conversion efficiencies. The nanometre (electron) and micrometre (photon) scale interfaces between the crystalline domains that make up solution-processed solar cells are crucial for efficient charge transport. These interfaces include large surface area junctions between photoelectron donors and acceptors, the intralayer grain boundaries within the absorber, and the interfaces between photoactive layers and the top and bottom contacts. Controlling the collection and minimizing the trapping of charge carriers at these boundaries is crucial to efficiency.

IRIS Mission Operations Director's Colloquium

NASA Technical Reports Server (NTRS)

Carvalho, Robert; Mazmanian, Edward A.

2014-01-01

Pursuing the Mysteries of the Sun: The Interface Region Imaging Spectrograph (IRIS) Mission. Flight controllers from the IRIS mission will present their individual experiences on IRIS from development through the first year of flight. This will begin with a discussion of the unique nature of IRISs mission and science, and how it fits into NASA's fleet of solar observatories. Next will be a discussion of the critical roles Ames contributed in the mission including spacecraft and flight software development, ground system development, and training for launch. This will be followed by experiences from launch, early operations, ongoing operations, and unusual operations experiences. The presentation will close with IRIS science imagery and questions.

Rotary Transformer

NASA Technical Reports Server (NTRS)

McLyman, Colonel Wm. T.

1996-01-01

None given. From first Par: Many spacecraft (S/C) and surface rovers require the transfer of signals and power across rotating interfaces. Science instruments, antennas and solar arrays are elements needing rotary power transfer for certain (S/C) configurations. Delivery of signal and power has mainly been done by using the simplest means, the slip ring approach. This approach, although simple, leaves debris generating noise over a period of time...The rotary transformer is a good alternative to slip rings for signal and power transfer.

A First for NASA's IRIS: Observing a Gigantic Eruption of Solar Material

NASA Image and Video Library

2014-05-30

Watch a video from this event here: www.flickr.com/photos/gsfc/14118958800/ A coronal mass ejection, or CME, surged off the side of the sun on May 9, 2014, and NASA's newest solar observatory caught it in extraordinary detail. This was the first CME observed by the Interface Region Imaging Spectrograph, or IRIS, which launched in June 2013 to peer into the lowest levels of the sun's atmosphere with better resolution than ever before. Watch the movie to see how a curtain of solar material erupts outward at speeds of 1.5 million miles per hour. Read more: 1.usa.gov/1kp7O4F NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Photoinduced charge separation at polymer-fullerene interfaces of BHJ solar cells (Conference Presentation)

NASA Astrophysics Data System (ADS)

Poluektov, Oleg G.; Niklas, Jens; Mardis, Kristy

2016-09-01

While photovoltaic cells are highly promising man-made devices for direct solar energy utilization, a number of fundamental questions about how the organic bulk heterojunction cell enables efficient long-lived and long-range charge separation remain unanswered. These questions were address by employing an advanced suite of EPR spectroscopy in combination with DFT calculations to study mechanism of charge separation at the polymer-fullerene interfaces of photo-active BHJ. Observed charge delocalization in BHJ upon photoinduced ET is analogous to that in organic donor-acceptor material. This is an efficient mechanism of charge stabilization in photosynthetic assemblies. Time-resolved EPR spectra show a strong polarization pattern for all polymer-fullerene blends under study, which is caused by non-Boltzmann population of the electron spin energy levels in the radical pairs. The first observation of this phenomenon was reported in natural and artificial photosynthetic assemblies, and comparison with these systems allows us to better understand charge separation processes in OPVs. The spectral analysis presented here, in combination with DFT calculations, shows that CS processes in OPV materials are similar to that in organic photosynthetic systems. This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences, under Contract DE-AC02-06CH11357 at Argonne National Laboratory.

SPS silicon reference system

NASA Technical Reports Server (NTRS)

Woodcock, G. R.

1980-01-01

The design analysis of a silicon power conversion system for the solar power satellite (SPS) is summarized. The solar array, consisting of glass encapsulated 50 micrometer silicon solar cells, is described. The general scheme for power distribution to the array/antenna interface is described. Degradation by proton irradiation is considered. The interface between the solar array and the klystron equipped power transmitter is described.

Al+Si Interface Optical Properties Obtained in the Si Solar Cell Configuration

DOE PAGES

Subedi, Indra; Silverman, Timothy J.; Deceglie, Michael G.; ...

2017-10-18

Al is a commonly used material for rear side metallization in commercial silicon (Si) wafer solar cells. In this study, through-the-silicon spectroscopic ellipsometry is used in a test sample to measure Al+Si interface optical properties like those in Si wafer solar cells. Two different spectroscopic ellipsometers are used for measurement of Al+Si interface optical properties over the 1128-2500 nm wavelength range. For validation, the measured interface optical properties are used in a ray tracing simulation over the 300-2500 nm wavelength range for an encapsulated Si solar cell having random pyramidal texture. The ray tracing model matches well with the measuredmore » total reflectance at normal incidence of a commercially available Si module. The Al+Si optical properties presented here enable quantitative assessment of major irradiance/current flux losses arising from reflection and parasitic absorption in encapsulated Si solar cells.« less

Al+Si Interface Optical Properties Obtained in the Si Solar Cell Configuration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Subedi, Indra; Silverman, Timothy J.; Deceglie, Michael G.

Al is a commonly used material for rear side metallization in commercial silicon (Si) wafer solar cells. In this study, through-the-silicon spectroscopic ellipsometry is used in a test sample to measure Al+Si interface optical properties like those in Si wafer solar cells. Two different spectroscopic ellipsometers are used for measurement of Al+Si interface optical properties over the 1128-2500 nm wavelength range. For validation, the measured interface optical properties are used in a ray tracing simulation over the 300-2500 nm wavelength range for an encapsulated Si solar cell having random pyramidal texture. The ray tracing model matches well with the measuredmore » total reflectance at normal incidence of a commercially available Si module. The Al+Si optical properties presented here enable quantitative assessment of major irradiance/current flux losses arising from reflection and parasitic absorption in encapsulated Si solar cells.« less

NASA's IRIS Observed a Gigantic Eruption on the Sun!

NASA Image and Video Library

2014-05-30

A coronal mass ejection, or CME, surged off the side of the sun on May 9, 2014, and NASA's newest solar observatory caught it in extraordinary detail. This was the first CME observed by the Interface Region Imaging Spectrograph, or IRIS, which launched in June 2013 to peer into the lowest levels of the sun's atmosphere with better resolution than ever before. Watch the movie to see how a curtain of solar material erupts outward at speeds of 1.5 million miles per hour. Read more: 1.usa.gov/1kp7O4F Credit: NASA's Goddard Space Flight Center NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Coronal Magnetism and Forward Solarsoft Idl Package

NASA Astrophysics Data System (ADS)

Gibson, S. E.

2014-12-01

The FORWARD suite of Solar Soft IDL codes is a community resource for model-data comparison, with a particular emphasis on analyzing coronal magnetic fields. FORWARD may be used both to synthesize a broad range of coronal observables, and to access and compare to existing data. FORWARD works with numerical model datacubes, interfaces with the web-served Predictive Science Inc MAS simulation datacubes and the Solar Soft IDL Potential Field Source Surface (PFSS) package, and also includes several analytic models (more can be added). It connects to the Virtual Solar Observatory and other web-served observations to download data in a format directly comparable to model predictions. It utilizes the CHIANTI database in modeling UV/EUV lines, and links to the CLE polarimetry synthesis code for forbidden coronal lines. FORWARD enables "forward-fitting" of specific observations, and helps to build intuition into how the physical properties of coronal magnetic structures translate to observable properties.

NASA's Evolutionary Xenon Thruster: The NEXT Ion Propulsion System for Solar System Exploration

NASA Technical Reports Server (NTRS)

Pencil, Eric J.; Benson, Scott W.

2008-01-01

This viewgraph presentation reviews NASA s Evolutionary Xenon Thruster (NEXT) Ion Propulsion system. The NEXT project is developing a solar electric ion propulsion system. The NEXT project is advancing the capability of ion propulsion to meet NASA robotic science mission needs. The NEXT system is planned to significantly improve performance over the state of the art electric propulsion systems, such as NASA Solar Electric Propulsion Technology Application Readiness (NSTAR). The status of NEXT development is reviewed, including information on the NEXT Thruster, the power processing unit, the propellant management system (PMS), the digital control interface unit, and the gimbal. Block diagrams NEXT system are presented. Also a review of the lessons learned from the Dawn and NSTAR systems is provided. In summary the NEXT project activities through 2007 have brought next-generation ion propulsion technology to a sufficient maturity level.

The Philosophy of User Interfaces in HELIO and the Importance of CASSIS

NASA Astrophysics Data System (ADS)

Bonnin, X.; Aboudarham, J.; Renié, C.; Csillaghy, A.; Messerotti, M.; Bentley, R. D.

2012-09-01

HELIO is a European project funded under FP7 (Project No. 238969). One of its goals as a Heliospheric Virtual Observatory is to provide an easy access to many datasets scattered all over the world, in the fields of Solar physics, Heliophysics, and Planetary magnetospheres. The efficiency of such a tool is very much related to the quality of the user interface. HELIO infrastructure is based on a Service Oriented Architecture (SOA), regrouping a network of standalone components, which allows four main types of interfaces: - HELIO Front End (HFE) is a browser-based user interface, which offers a centralized access to the HELIO main functionalities. Especially, it provides the possibility to reach data directly, or to refine selection by determination of observing characteristics, such as which instrument was observing at that time, which instrument was at this location, etc. - Many services/components provide their own standalone graphical user interface. While one can directly access individually each of these interfaces, they can also be connected together. - Most services also provide direct access for any tools through a public interface. A small java library, called Java API, simplifies this access by providing client stubs for services and shields the user from security, discovery and failover issues. - Workflows capabilities are available in HELIO, allowing complex combination of queries over several services. We want the user to be able to navigate easily, at his needs, through the various interfaces, and possibly use a specific one in order to make much-dedicated queries. We will also emphasize the importance of the CASSIS project (Coordination Action for the integration of Solar System Infrastructure and Science) in encouraging the interoperability necessary to undertake scientific studies that span disciplinary boundaries. If related projects follow the guidelines being developed by CASSIS then using external resources with HELIO will be greatly simplified.

Achieving high performance polymer optoelectronic devices for high efficiency, long lifetime and low fabrication cost

NASA Astrophysics Data System (ADS)

Huang, Jinsong

This thesis described three types of organic optoelectronic devices: polymer light emitting diodes (PLED), polymer photovoltaic solar cell, and organic photo detector. The research in this work focuses improving their performance including device efficiency, operation lifetime simplifying fabrication process. With further understanding in PLED device physics, we come up new device operation model and improved device architecture design. This new method is closely related to understanding of the science and physics at organic/metal oxide and metal oxide/metal interface. In our new device design, both material and interface are considered in order to confine and balance all injected carriers, which has been demonstrated very be successful in increasing device efficiency. We created two world records in device efficiency: 18 lm/W for white emission fluorescence PLED, 22 lm/W for red emission phosphorescence PLED. Slow solvent drying process has been demonstrated to significantly increase device efficiency in poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C 61-butyric acid methyl ester (PCBM) mixture polymer solar cell. From the mobility study by time of flight, the increase of efficiency can be well correlated to the improved carrier transport property due to P3HT crystallization during slow solvent drying. And it is found that, similar to PLED, balanced carrier mobility is essential in high efficient polymer solar cell. There is also a revolution in our device fabrication method. A unique device fabrication method is presented by an electronic glue based lamination process combined with interface modification as a one-step polymer solar cell fabrication process. It can completely skip the thermal evaporation process, and benefit device lifetime by several merits: no air reactive. The device obtained is metal free, semi-transparent, flexible, self-encapsulated, and comparable efficiency with that by regular method. We found the photomultiplication (PM) phenomenon in C60 based device accidentally. The high PM factor makes it good candidate for photo detector. The high gain was assigned to the trapped-charge induced enhanced-injection at C60/PEDOT:PSS interface.

Exploring Electrical and Magnetic Resonances from Coherently Correlated Long-Lived Radical Pairs towards Development of Negative Refractive-Index Materials

DTIC Science & Technology

2015-01-03

Dissociation in Perovskite Solar Cells Yu-Che Hsiao, Ting Wu, Mingxing Li, and Bin Hu Advanced Materials, DOI: 10.1002/adma.201405946, 2015 2...Electrode Interface and Donor/Acceptor Interface via Charge Dissociation in Organic Solar Cells at Device-Operating Condition Ting Wu, Yu-Che Hsiao...exchange energy at donor:acceptor interfaces in organic solar cells Mingxing Li, Hongfeng Wang, Lei He, Huidong Zang, Hengxing Xu, and Bin Hu Appl

2014 Summer Series - Robert Carvalho - Pursuing the Mysteries of the Sun: The IRIS Mission

NASA Image and Video Library

2014-06-19

Pursuing the Mysteries of the Sun: The Interface Region Imaging Spectrograph (IRIS) Mission. Flight controllers from the IRIS mission will present their individual experiences on IRIS from development through the first year of flight. This will begin with a discussion of the unique nature of IRIS's mission and science, and how it fits into NASA's fleet of solar observatories. Next will be a discussion of the critical roles Ames contributed in the mission including spacecraft and flight software development, ground system development, and training for launch. This will be followed by experiences from launch, early operations, ongoing operations, and unusual operations experiences. The presentation will close with IRIS science imagery and questions.

MER SPICE Interface

NASA Technical Reports Server (NTRS)

Sayfi, Elias

2004-01-01

MER SPICE Interface is a software module for use in conjunction with the Mars Exploration Rover (MER) mission and the SPICE software system of the Navigation and Ancillary Information Facility (NAIF) at NASA's Jet Propulsion Laboratory. (SPICE is used to acquire, record, and disseminate engineering, navigational, and other ancillary data describing circumstances under which data were acquired by spaceborne scientific instruments.) Given a Spacecraft Clock value, MER SPICE Interface extracts MER-specific data from SPICE kernels (essentially, raw data files) and calculates values for Planet Day Number, Local Solar Longitude, Local Solar Elevation, Local Solar Azimuth, and Local Solar Time (UTC). MER SPICE Interface was adapted from a subroutine, denoted m98SpiceIF written by Payam Zamani, that was intended to calculate SPICE values for the Mars Polar Lander. The main difference between MER SPICE Interface and m98SpiceIf is that MER SPICE Interface does not explicitly call CHRONOS, a time-conversion program that is part of a library of utility subprograms within SPICE. Instead, MER SPICE Interface mimics some portions of the CHRONOS code, the advantage being that it executes much faster and can efficiently be called from a pipeline of events in a parallel processing environment.

Selenium Interlayer for High-Efficiency Multijunction Solar Cell

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A (Inventor)

2015-01-01

A multi junction solar cell is provided and includes multiple semiconducting layers and an interface layer disposed between the multiple semiconducting layers. The interface layer is made from an interface bonding material that has a refractive index such that a ratio of a refractive index of each of the multiple semiconducting layers to the refractive index of the interface bonding material is less than or equal to 1.5.

Selenium Interlayer for High-Efficiency Multijunction Solar Cell

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A. (Inventor)

2016-01-01

A multi-junction solar cell is provided and includes multiple semiconducting layers and an interface layer disposed between the multiple semiconducting layers. The interface layer is made from an interface bonding material that has a refractive index such that a ratio of a refractive index of each of the multiple semiconducting layers to the refractive index of the interface bonding material is less than or equal to 1.5.

Enhanced stability of ZnO-based inverted organic photovoltaic devices by phosphonic acid modification

NASA Astrophysics Data System (ADS)

MacLeod, Bradley; Tremolet de Villers, Bertrand; Cowan, Sarah; Ratcliff, Erin; Olson, Dana

2014-03-01

Solution-processed ZnO thin films are now commonly used as n-type bottom contacts in inverted-geometry organic photovoltaics (OPVs). The use of ZnO eliminates the need for highly-reactive top-contact (air-interface) electrode material, such as calcium and aluminum which are commonly used in conventional geometries, which enables operational lifetimes of unencapsulated devices to shift from minutes or hours to days. Modification of the ZnO film by self-assembled monolayers (SAMs) has been shown to enhance performance as well as air-stability during storage. We modify ZnO with dipolar phosphonic acids and observe enhanced performance and stability. We show for the first time devices measured under continuous illumination at one-sun intensity which have significantly enhanced stability when utilizing SAM-modified ZnO. These continuous-illumination stability measurements allow us to investigate the degradation mechanisms of these more stable inverted OPV devices. This work was was supported by of the Center for Interface Science: Solar Electric Materials (CISSEM), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001084.

The Solar Wind and Geomagnetic Activity as a Function of Time Relative to Corotating Interaction Regions

NASA Technical Reports Server (NTRS)

McPherron, Robert L.; Weygand, James

2006-01-01

Corotating interaction regions during the declining phase of the solar cycle are the cause of recurrent geomagnetic storms and are responsible for the generation of high fluxes of relativistic electrons. These regions are produced by the collision of a high-speed stream of solar wind with a slow-speed stream. The interface between the two streams is easily identified with plasma and field data from a solar wind monitor upstream of the Earth. The properties of the solar wind and interplanetary magnetic field are systematic functions of time relative to the stream interface. Consequently the coupling of the solar wind to the Earth's magnetosphere produces a predictable sequence of events. Because the streams persist for many solar rotations it should be possible to use terrestrial observations of past magnetic activity to predict future activity. Also the high-speed streams are produced by large unipolar magnetic regions on the Sun so that empirical models can be used to predict the velocity profile of a stream expected at the Earth. In either case knowledge of the statistical properties of the solar wind and geomagnetic activity as a function of time relative to a stream interface provides the basis for medium term forecasting of geomagnetic activity. In this report we use lists of stream interfaces identified in solar wind data during the years 1995 and 2004 to develop probability distribution functions for a variety of different variables as a function of time relative to the interface. The results are presented as temporal profiles of the quartiles of the cumulative probability distributions of these variables. We demonstrate that the storms produced by these interaction regions are generally very weak. Despite this the fluxes of relativistic electrons produced during those storms are the highest seen in the solar cycle. We attribute this to the specific sequence of events produced by the organization of the solar wind relative to the stream interfaces. We also show that there are large quantitative differences in various parameters between the two cycles.

Engineering Interface Structure to Improve Efficiency and Stability of Organometal Halide Perovskite Solar Cells.

PubMed

Qiu, Longbin; Ono, Luis K; Jiang, Yan; Leyden, Matthew R; Raga, Sonia R; Wang, Shenghao; Qi, Yabing

2018-01-18

The rapid rise of power conversion efficiency (PCE) of low cost organometal halide perovskite solar cells suggests that these cells are a promising alternative to conventional photovoltaic technology. However, anomalous hysteresis and unsatisfactory stability hinder the industrialization of perovskite solar cells. Interface engineering is of importance for the fabrication of highly stable and hysteresis free perovskite solar cells. Here we report that a surface modification of the widely used TiO 2 compact layer can give insight into interface interaction in perovskite solar cells. A highest PCE of 18.5% is obtained using anatase TiO 2 , but the device is not stable and degrades rapidly. With an amorphous TiO 2 compact layer, the devices show a prolonged lifetime but a lower PCE and more pronounced hysteresis. To achieve a high PCE and long lifetime simultaneously, an insulating polymer interface layer is deposited on top of TiO 2 . Three polymers, each with a different functional group (hydroxyl, amino, or aromatic group), are investigated to further understand the relation of interface structure and device PCE as well as stability. We show that it is necessary to consider not only the band alignment at the interface, but also interface chemical interactions between the thin interface layer and the perovskite film. The hydroxyl and amino groups interact with CH 3 NH 3 PbI 3 leading to poor PCEs. In contrast, deposition of a thin layer of polymer consisting of an aromatic group to prevent the direct contact of TiO 2 and CH 3 NH 3 PbI 3 can significantly enhance the device stability, while the same time maintaining a high PCE. The fact that a polymer interface layer on top of TiO 2 can enhance device stability, strongly suggests that the interface interaction between TiO 2 and CH 3 NH 3 PbI 3 plays a crucial role. Our work highlights the importance of interface structure and paves the way for further optimization of PCEs and stability of perovskite solar cells.

Graphene interfaced perovskite solar cells: Role of graphene flake size

NASA Astrophysics Data System (ADS)

Sakorikar, Tushar; Kavitha, M. K.; Tong, Shi Wun; Vayalamkuzhi, Pramitha; Loh, Kian Ping; Jaiswal, Manu

2018-04-01

Graphene interfaced inverted planar heterojunction perovskite solar cells are fabricated by facile solution method and studied its potential as hole conducting layer. Reduced graphene oxide (rGO) with small and large flake size and Polyethylenedioxythiophene:polystyrene sulfonate (PEDOT:PSS) are utilized as hole conducting layers in different devices. For the solar cell employing PEDOT:PSS as hole conducting layer, 3.8 % photoconversion efficiency is achieved. In case of solar cells fabricated with rGO as hole conducting layer, the efficiency of the device is strongly dependent on flake size. With all other fabrication conditions kept constant, the efficiency of graphene-interfaced solar cell improves by a factor of 6, by changing the flake size of graphene oxide. We attribute this effect to uniform coverage of graphene layer and improved electrical percolation network.

Interface engineering of CsPbBr3/TiO2 heterostructure with enhanced optoelectronic properties for all-inorganic perovskite solar cells

NASA Astrophysics Data System (ADS)

Qian, Chong-Xin; Deng, Zun-Yi; Yang, Kang; Feng, Jiangshan; Wang, Ming-Zi; Yang, Zhou; Liu, Shengzhong Frank; Feng, Hong-Jian

2018-02-01

Interface engineering has become a vital method in accelerating the development of perovskite solar cells in the past few years. To investigate the effect of different contacted surfaces of a light absorber with an electron transporting layer, TiO2, we synthesize CsPbBr3/TiO2 thin films with two different interfaces (CsBr/TiO2 and PbBr2/TiO2). Both interfacial heterostructures exhibit enhanced visible light absorption, and the CsBr/TiO2 thin film presents higher absorption than the PbBr2/TiO2 interface, which is attributed to the formation of interface states and the decreased interface bandgap. Furthermore, compared with the PbBr2/TiO2 interface, CsBr/TiO2 solar devices present larger output short circuit current and shorter photoluminescence decay time, which indicates that the CsBr contacting layer with TiO2 can better extract and separate the photo-induced carriers. The first-principles calculations confirm that, due to the existence of staggered gap (type II) offset junction and the interface states, the CsBr/TiO2 interface can more effectively separate the photo-induced carriers and thus drive the electron transfer from the CsPbBr3 perovskite layer to the TiO2 layer. These results may be beneficial to exploit the potential application of all-inorganic perovskite CsPbBr3-based solar cells through the interface engineering route.

A Python-based interface to examine motions in time series of solar images

NASA Astrophysics Data System (ADS)

Campos-Rozo, J. I.; Vargas Domínguez, S.

2017-10-01

Python is considered to be a mature programming language, besides of being widely accepted as an engaging option for scientific analysis in multiple areas, as will be presented in this work for the particular case of solar physics research. SunPy is an open-source library based on Python that has been recently developed to furnish software tools to solar data analysis and visualization. In this work we present a graphical user interface (GUI) based on Python and Qt to effectively compute proper motions for the analysis of time series of solar data. This user-friendly computing interface, that is intended to be incorporated to the Sunpy library, uses a local correlation tracking technique and some extra tools that allows the selection of different parameters to calculate, vizualize and analyze vector velocity fields of solar data, i.e. time series of solar filtergrams and magnetograms.

Local Time-Dependent Charging in a Perovskite Solar Cell.

PubMed

Bergmann, Victor W; Guo, Yunlong; Tanaka, Hideyuki; Hermes, Ilka M; Li, Dan; Klasen, Alexander; Bretschneider, Simon A; Nakamura, Eiichi; Berger, Rüdiger; Weber, Stefan A L

2016-08-03

Efficient charge extraction within solar cells explicitly depends on the optimization of the internal interfaces. Potential barriers, unbalanced charge extraction, and interfacial trap states can prevent cells from reaching high power conversion efficiencies. In the case of perovskite solar cells, slow processes happening on time scales of seconds cause hysteresis in the current-voltage characteristics. In this work, we localized and investigated these slow processes using frequency-modulation Kelvin probe force microscopy (FM-KPFM) on cross sections of planar methylammonium lead iodide (MAPI) perovskite solar cells. FM-KPFM can map the charge density distribution and its dynamics at internal interfaces. Upon illumination, space charge layers formed at the interfaces of the selective contacts with the MAPI layer within several seconds. We observed distinct differences in the charging dynamics at the interfaces of MAPI with adjacent layers. Our results indicate that more than one process is involved in hysteresis. This finding is in agreement with recent simulation studies claiming that a combination of ion migration and interfacial trap states causes the hysteresis in perovskite solar cells. Such differences in the charging rates at different interfaces cannot be separated by conventional device measurements.

Preparing a Nation for the Eclipse of a Generation -

NASA Astrophysics Data System (ADS)

Speck, Angela; Habbal, Shadia; Tresch Fienberg, Richard; Kentrianakis, Michael; Fraknoi, Andrew; Nordgren, Tyler; Penn, Matthew; Pasachoff, Jay M.; Bakich, Michael; Winter, Henry; Gay, Pamela; Motta, Mario

2018-01-01

On August 21st 2017, there was a total solar eclipse visible from a vast swath of the US.In preparation for that event, the American Astronomical society created a taskforce charged with planning for the eclipse for the entire nation. The preparations included interfacing with the public, the media, non-profit organizations and governmental organizations. Preliminary data suggests that nearly 90% of American adults watched the eclipse either directly or via live streams. Moreover, there were no major problems associated with the event, in spite of valiant attempts from, e.g. imprope solar viewing materials. The eclipse offered opportunities for many scientific experiments within and ebyond astronomy. Here we present on the work of the taskforce, and the lessons learned as well as lesser known science experiments undertaken during the eclipse.

An Observation Knowledgebase for Hinode Data

NASA Astrophysics Data System (ADS)

Hurlburt, Neal E.; Freeland, S.; Green, S.; Schiff, D.; Seguin, R.; Slater, G.; Cirtain, J.

2007-05-01

We have developed a standards-based system for the Solar Optical and X Ray Telescopes on the Hinode orbiting solar observatory which can serve as part of a developing Heliophysics informatics system. Our goal is to make the scientific data acquired by Hinode more accessible and useful to scientists by allowing them to do reasoning and flexible searches on observation metadata and to ask higher-level questions of the system than previously allowed. The Hinode Observation Knowledgebase relates the intentions and goals of the observation planners (as-planned metadata) with actual observational data (as-run metadata), along with connections to related models, data products and identified features (follow-up metadata) through a citation system. Summaries of the data (both as image thumbnails and short "film strips") serve to guide researchers to the observations appropriate for their research, and these are linked directly to the data catalog for easy extraction and delivery. The semantic information of the observation (Field of view, wavelength, type of observable, average cadence etc.) is captured through simple user interfaces and encoded using the VOEvent XML standard (with the addition of some solar-related extensions). These interfaces merge metadata acquired automatically during both mission planning and an data analysis (see Seguin et. al. 2007 at this meeting) phases with that obtained directly from the planner/analyst and send them to be incorporated into the knowledgebase. The resulting information is automatically rendered into standard categories based on planned and recent observations, as well as by popularity and recommendations by the science team. They are also directly searchable through both and web-based searches and direct calls to the API. Observations details can also be rendered as RSS, iTunes and Google Earth interfaces. The resulting system provides a useful tool to researchers and can act as a demonstration for larger, more complex systems.

Air-annealing of Cu(In, Ga)Se2/CdS and performances of CIGS solar cells

NASA Astrophysics Data System (ADS)

Niu, X.; Zhu, H.; Liang, X.; Guo, Y.; Li, Z.; Mai, Y.

2017-12-01

In this study, the annealing treatment on Cu(In, Ga)Se2 (CIGS)/CdS interface in air is systematically investigated under different annealing temperatures from room temperature to 150 °C and different durations. It is found that when CIGS/CdS interface is annealed for a proper duration the corresponding CIGS thin film solar cells show enhanced open circuit voltage (Voc) and fill factor (FF) as well as corresponding conversion efficiency. The capacitance-voltage (C-V) and time-resolved photoluminescence (TR-PL) measurement results indicate that the CIGS thin film solar cells exhibit an increase in net defect density (NCV) and long lifetime for the carriers, respectively, after the annealing treatment of CIGS/CdS at a mediate annealing temperature here. Moreover, the net defect density of annealed solar cells at higher annealing temperatures for a long duration is reduced. All the variations in the solar cell performances, NCV and carrier lifetime would be related to the passivation of Se vacancies and InCu defects, surface (interface) states as well as positive interface discharges and Cu migration etc. A high efficiency CIGS solar cell of 14.4% is achieved. The optimized solar cell of 17.2% with a MgF2 anti-reflective layer has been obtained.

Influence of interface layer preparation on the electrical and spectral characteristics of GaN/Si solar cells

NASA Astrophysics Data System (ADS)

Shugurov, K. U.; Mozharov, A. M.; Sapunov, G. A.; Fedorov, V. V.; Bolshakov, A. D.; Mukhin, I. S.

2018-03-01

Volt-ampere and spectral characteristics of GaN/Si solar cell samples differing in interface layer preparation are obtained and analyzed. External quantum efficiency curves are experimentally determined via excitation with a 532 nm incident radiation wavelength. It is demonstrated that interface preparation has a significant influence on photovoltaic characteristics of the studied samples.

NASA's Best-Observed X-Class Flare of All Time

NASA Image and Video Library

2014-05-07

On March 29, 2014 the sun released an X-class flare. It was observed by NASA's Interface Region Imaging Spectrograph, or IRIS; NASA's Solar Dynamics Observatory, or SDO; NASA's Reuven Ramaty High Energy Solar Spectroscopic Imager, or RHESSI; the Japanese Aerospace Exploration Agency's Hinode; and the National Solar Observatory's Dunn Solar Telescope located at Sacramento Peak in New Mexico. To have a record of such an intense flare from so many observatories is unprecedented. Such research can help scientists better understand what catalyst sets off these large explosions on the sun. Perhaps we may even some day be able to predict their onset and forewarn of the radio blackouts solar flares can cause near Earth - blackouts that can interfere with airplane, ship and military communications. Read more: 1.usa.gov/1kMDQbO Join our Google+ Hangout on May 8 at 2:30pm EST: go.nasa.gov/1mwbBEZ Credit: NASA Goddard NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Photovoltaic Performance and Interface Behaviors of Cu(In,Ga)Se2 Solar Cells with a Sputtered-Zn(O,S) Buffer Layer by High-Temperature Annealing.

PubMed

Wi, Jae-Hyung; Kim, Tae Gun; Kim, Jeong Won; Lee, Woo-Jung; Cho, Dae-Hyung; Han, Won Seok; Chung, Yong-Duck

2015-08-12

We selected a sputtered-Zn(O,S) film as a buffer material and fabricated a Cu(In,Ga)Se2 (CIGS) solar cell for use in monolithic tandem solar cells. A thermally stable buffer layer was required because it should withstand heat treatment during processing of top cell. Postannealing treatment was performed on a CIGS solar cell in vacuum at temperatures from 300-500 °C to examine its thermal stability. Serious device degradation particularly in VOC was observed, which was due to the diffusion of thermally activated constituent elements. The elements In and Ga tend to out-diffuse to the top surface of the CIGS, while Zn diffuses into the interface of Zn(O,S)/CIGS. Such rearrangement of atomic fractions modifies the local energy band gap and band alignment at the interface. The notch-shape induced at the interface after postannealing could function as an electrical trap during electron transport, which would result in the reduction of solar cell efficiency.

The surface science of nanocrystals

NASA Astrophysics Data System (ADS)

Boles, Michael A.; Ling, Daishun; Hyeon, Taeghwan; Talapin, Dmitri V.

2016-02-01

All nanomaterials share a common feature of large surface-to-volume ratio, making their surfaces the dominant player in many physical and chemical processes. Surface ligands -- molecules that bind to the surface -- are an essential component of nanomaterial synthesis, processing and application. Understanding the structure and properties of nanoscale interfaces requires an intricate mix of concepts and techniques borrowed from surface science and coordination chemistry. Our Review elaborates these connections and discusses the bonding, electronic structure and chemical transformations at nanomaterial surfaces. We specifically focus on the role of surface ligands in tuning and rationally designing properties of functional nanomaterials. Given their importance for biomedical (imaging, diagnostics and therapeutics) and optoelectronic (light-emitting devices, transistors, solar cells) applications, we end with an assessment of application-targeted surface engineering.

Radioisotope Heater Unit-Based Stirling Power Convertor Development at NASA Glenn Research Center

NASA Technical Reports Server (NTRS)

Wilson, Scott D.; Geng, Steven M.; Penswick, Lawrence; Schmitz, Paul C.

2017-01-01

Stirling Radioisotope Power Systems (RPS) are being developed as an option to provide power on future space science missions where robotic spacecraft will orbit, flyby, land or rove. A variety of mission concepts have been studied by NASA and the U. S. Department of Energy that would utilize RPS for landers, probes, and rovers and only require milliwatts to tens of watts of power. These missions would contain science measuring instruments that could be distributed across planetary surfaces or near objects of interest in space solar flux insufficient for using solar cells. A low power Stirling convertor is being developed to provide an RPS option for future low power applications. Initial concepts convert heat available from several Radioisotope Heater Units to electrical power for spacecraft instruments and communication. Initial development activity includes defining and evaluating a variety of Stirling configurations and selecting one for detailed design, research of advanced manufacturing methods that could simplify fabrication, evaluating thermal interfaces, characterizing components and subassemblies to validate design codes, and preparing for an upcoming demonstration of proof of concept in a laboratory environment.

Basic research needs and opportunities on interfaces in solar materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Czanderna, A. W.; Gottschall, R. J.

1981-04-01

The workshop on research needs and recommended research programs on interfaces in solar energy conversion devices was held June 30-July 3, 1980. The papers deal mainly with solid-solid, solid-liquid, and solid-gas interfaces, sometimes involving multilayer solid-solid interfaces. They deal mainly with instrumental techniques of studying these interfaces so they can be optimized, so they can be fabricated with quality control and so changes with time can be forecast. The latter is required because a long lifetime (20 yrs is suggested) is necessary for economic reasons. Fifteen papers have been entered individually into EDB and ERA. (LTN)

Rational material, interface, and device engineering for high-performance polymer and perovskite solar cells (Presentation Recording)

NASA Astrophysics Data System (ADS)

Jen, Alex K.

2015-10-01

The performance of polymer and hybrid solar cells is also strongly dependent on their efficiency in harvesting light, exciton dissociation, charge transport, and charge collection at the metal/organic/metal oxide or the metal/perovskite/metal oxide interfaces. Our laboratory employs a molecular engineering approach to develop processible low band-gap polymers with high charge carrier mobility that can enhance power conversion efficiency of the single junction solar cells to values as high as ~11%. We have also developed several innovative strategies to modify the interface of bulk-heterojunction devices and create new device architectures to fully explore their potential for solar applications. In this talk, the integrated approach of combining material design, interface, and device engineering to significantly improve the performance of polymer and hybrid perovskite photovoltaic cells will be discussed. Specific emphasis will be placed on the development of low band-gap polymers with reduced reorganizational energy and proper energy levels, formation of optimized morphology of active layer, and minimized interfacial energy barriers using functional conductive surfactants. At the end, several new device architectures and optical engineering strategies to make tandem cells and semitransparent solar cells will be discussed to explore the full promise of polymer and perovskite hybrid solar cells.

The ISES: A non-intrusive medium for in-space experiments in on-board information extraction

NASA Technical Reports Server (NTRS)

Murray, Nicholas D.; Katzberg, Stephen J.; Nealy, Mike

1990-01-01

The Information Science Experiment System (ISES) represents a new approach in applying advanced systems technology and techniques to on-board information extraction in the space environment. Basically, what is proposed is a 'black box' attached to the spacecraft data bus or local area network. To the spacecraft the 'black box' appears to be just another payload requiring power, heat rejection, interfaces, adding weight, and requiring time on the data management and communication system. In reality, the 'black box' is a programmable computational resource which eavesdrops on the data network, taking and producing selectable, real-time science data back on the network. This paper will present a brief overview of the ISES Concept and will discuss issues related to applying the ISES to the polar platform and Space Station Freedom. Critical to the operation of ISES is the viability of a payload-like interface to the spacecraft data bus or local area network. Study results that address this question will be reviewed vis-a-vis the solar platform and the core space station. Also, initial results of processing science and other requirements for onboard, real-time information extraction will be presented with particular emphasis on the polar platform. Opportunities for a broader range of applications on the core space station will also be discussed.

The Importance of Reconnection at Sector Boundaries: Another Space Weather Hazard?

NASA Astrophysics Data System (ADS)

Qi, Y.; Lai, H.; Russell, C. T.

2017-12-01

Sector Boundaries are interfaces between nearly oppositely directed magnetic flux in the solar wind. When the leading solar wind stream is moving more slowly than the following stream a high-pressure ridge appears at the interface, that compresses the plasma sometimes leading to a forward and reverse shock pair that slows the fast stream and accelerate the slow stream. If reconnection at the interface between the streams occurs part of the magnetic flux will be annihilated but the plasma once associated with that magnetic flux remains near the interface causing a sometimes significant short-lived dynamic pressure increase. The declining phase of solar cycle 24 exhibits several examples of the phenomenon with densities reaching over 80 protons cm-3 at speed of about 400 km sec-1. We examine the solar wind context of the phenomenon and the consequences at the magnetosphere using space-based and ground-based observations and comment on their possible generation of geomagnetically-induced currents.

Japanese Next Solar Mission: SOLAR-C

NASA Astrophysics Data System (ADS)

Sakao, T.; Solar-C, W. G.

2008-09-01

We present introductory overview on the next Japanese solar mission, SOLAR-C, which has been envisaged following the success of Hinode (SOLAR-B) mission. Two plans, Plan A and Plan B, are under extensive study from science objectives as well as engineering point of view. Plan A aims to perform out-of-ecliptic observations for investigating, with helioseismic approach, internal structure and dynamo mechanisms of the Sun. It also explores polar regions where fast solar wind is believed to be originated. The baseline orbit for Plan A is a circular orbit of 1 AU distance from the Sun, with its inclination at around, or greater than, 40 degrees. Plan B pursues small-scale plasma processes and structures in the solar atmosphere which attract growing interest, following Hinode discoveries, for understanding fully dynamism and magnetic nature of the atmosphere. With Plan B, high-angular-resolution investigation of the entire solar atmosphere (from the photosphere to the corona, including their interface layers, i.e., chromosphere and transition region) is to be performed with enhanced spectroscopic and spectro-polarimetric capability as compared with Hinode, together with enhanced sensitivity towards ultra-violet wavelengths. There has been wide and evolving support for the SOLAR-C mission not only from solar physics community but also from related research areas in Japan. We request SOLAR-C to be launched in mid. 2010s. Following the highly-successful achievements of international collaboration for Yohkoh and Hinode, we strongly hope the SOLAR-C mission be realized under extensive collaboration with European and U.S. partners. Japanese SOLAR-C working group was officially approved by ISAS/JAXA in December 2007 for mission studies and promoting international collaboration. It is expected that a single mission plan is to be proposed after one year of investigation on Plan A and Plan B.

Atomic Structure of Interface States in Silicon Heterojunction Solar Cells

NASA Astrophysics Data System (ADS)

George, B. M.; Behrends, J.; Schnegg, A.; Schulze, T. F.; Fehr, M.; Korte, L.; Rech, B.; Lips, K.; Rohrmüller, M.; Rauls, E.; Schmidt, W. G.; Gerstmann, U.

2013-03-01

Combining orientation dependent electrically detected magnetic resonance and g tensor calculations based on density functional theory we assign microscopic structures to paramagnetic states involved in spin-dependent recombination at the interface of hydrogenated amorphous silicon crystalline silicon (a-Si:H/c-Si) heterojunction solar cells. We find that (i) the interface exhibits microscopic roughness, (ii) the electronic structure of the interface defects is mainly determined by c-Si, (iii) we identify the microscopic origin of the conduction band tail state in the a-Si:H layer, and (iv) present a detailed recombination mechanism.

Characteristics of gradient-interface-structured ZnCdSSe quantum dots with modified interface and its application to quantum-dot-sensitized solar cells

NASA Astrophysics Data System (ADS)

Jeong, Da-Woon; Kim, Jae-Yup; Seo, Han Wook; Lim, Kyoung-Mook; Ko, Min Jae; Seong, Tae-Yeon; Kim, Bum Sung

2018-01-01

Colloidal quantum dots (QDs) are attractive materials for application in photovoltaics, LEDs, displays, and bio devices owing to their unique properties. In this study, we synthesized gradient-interface-structured ZnCdSSe QDs and modified the interface based on a thermodynamic simulation to investigate its optical and physical properties. In addition, the interface was modified by increasing the molar concentration of Se. QDs at the modified interface were applied to QD-sensitized solar cells, which showed a 25.5% increase in photoelectric conversion efficiency owing to the reduced electron confinement effect. The increase seems to be caused by the excited electrons being relatively easily transferred to the level of TiO2 owing to the reduced electron confinement effect. Consequently, the electron confinement effect was observed to be reduced by increasing the ZnSe (or Zn1-xCdxSe)-rich phase at the interface. This means that, based on the thermodynamic simulation, the interface between the core QDs and the surface of the QDs can be controlled. The improvement of optical and electronic properties by controlling interfaces and surfaces during the synthesis of QDs, as reported in this work, can be useful for many applications beyond solar cells.

Energy level alignment in TiO2/metal sulfide/polymer interfaces for solar cell applications.

PubMed

Lindblad, Rebecka; Cappel, Ute B; O'Mahony, Flannan T F; Siegbahn, Hans; Johansson, Erik M J; Haque, Saif A; Rensmo, Håkan

2014-08-28

Semiconductor sensitized solar cell interfaces have been studied with photoelectron spectroscopy to understand the interfacial electronic structures. In particular, the experimental energy level alignment has been determined for complete TiO2/metal sulfide/polymer interfaces. For the metal sulfides CdS, Sb2S3 and Bi2S3 deposited from single source metal xanthate precursors, it was shown that both driving forces for electron injection into TiO2 and hole transfer to the polymer decrease for narrower bandgaps. The energy level alignment results were used in the discussion of the function of solar cells with the same metal sulfides as light absorbers. For example Sb2S3 showed the most favourable energy level alignment with 0.3 eV driving force for electron injection and 0.4 eV driving force for hole transfer and also the most efficient solar cells due to high photocurrent generation. The energy level alignment of the TiO2/Bi2S3 interface on the other hand showed no driving force for electron injection to TiO2, and the performance of the corresponding solar cell was very low.

Tuning back contact property via artificial interface dipoles in Si/organic hybrid solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Dan; Department of Physics and Institute of Solid-state electronics physical, Ningbo University, Ningbo 315211; Sheng, Jiang, E-mail: shengjiang@nimte.ac.cn

2016-07-25

Back contact property plays a key role in the charge collection efficiency of c-Si/poly(3,4-ethylthiophene):poly(styrenesulfonate) hybrid solar cells (Si-HSCs), as an alternative for the high-efficiency and low-cost photovoltaic devices. In this letter, we utilize the water soluble poly (ethylene oxide) (PEO) to modify the Al/Si interface to be an Ohmic contact via interface dipole tuning, decreasing the work function of the Al film. This Ohmic contact improves the electron collection efficiency of the rear electrode, increasing the short circuit current density (J{sub sc}). Furthermore, the interface dipoles make the band bending downward to increase the total barrier height of built-in electricmore » field of the solar cell, enhancing the open circuit voltage (V{sub oc}). The PEO solar cell exhibits an excellent performance, 12.29% power conversion efficiency, a 25.28% increase from the reference solar cell without a PEO interlayer. The simple and water soluble method as a promising alternative is used to develop the interfacial contact quality of the rear electrode for the high photovoltaic performance of Si-HSCs.« less

State transition storyboards: A tool for designing the Goldstone solar system radar data acquisition system user interface software

NASA Technical Reports Server (NTRS)

Howard, S. D.

1987-01-01

Effective user interface design in software systems is a complex task that takes place without adequate modeling tools. By combining state transition diagrams and the storyboard technique of filmmakers, State Transition Storyboards were developed to provide a detailed modeling technique for the Goldstone Solar System Radar Data Acquisition System human-machine interface. Illustrations are included with a description of the modeling technique.

Changes in solar wind-magnetosphere coupling with solar cycle, season, and time relative to stream interfaces

NASA Astrophysics Data System (ADS)

McPherron, Robert L.; Baker, Daniel N.; Pulkkinen, T. I.; Hsu, T.-S.; Kissinger, J.; Chu, X.

2013-07-01

Geomagnetic activity depends on a variety of factors including solar zenith angle, solar UV, strength of the interplanetary magnetic field, speed and density of the solar wind, orientation of the Earth’s dipole, distance of the Earth from Sun, occurrence of CMEs and CIRs, and possibly other parameters. We have investigated some of these using state-dependant linear prediction filters. For a given state a prediction filter transforms a coupling function such as rectified solar wind electric field (VBs) to an output like the auroral electrojet index (AL). The area of this filter calculated from the sum of the filter coefficients measures the strength of the coupling. When the input and output are steady for a time longer than the duration of the filter the ratio of output to input is equal to this area. We find coupling strength defined in this way for Es=VBs to AL (and AU) is weakest at solar maximum and strongest at solar minimum. AL coupling displays a semiannual variation being weakest at the solstices and strongest at the equinoxes. AU coupling has only an annual variation being strongest at summer solstice. AL and AU coupling also vary with time relative to a stream interface. Es coupling is weaker after the interface, but ULF coupling is stronger. Total prediction efficiency remains about constant at the interface. The change in coupling strength with the solar cycle can be explained as an effect of more frequent saturation of the polar cap potential causing a smaller ratio of AL to Es. Stronger AL coupling at the equinoxes possibly indicates some process that makes magnetic reconnection less efficient when the dipole axis is tilted along the Earth-Sun line. Strong AU coupling at summer solstice is likely due to high conductivity in northern summer. Coupling changes at a stream interface are correlated with the presence of strong wave activity in ground and satellite measurements and may be an artifact of the method by which solar wind data are propagated.

Solar research with ALMA: Czech node of European ARC as your user-support infrastructure

NASA Astrophysics Data System (ADS)

Bárta, M.; Skokić, I.; Brajša, R.; Czech ARC Node Team

2017-08-01

ALMA (Atacama Large Millimeter/sub-millimeter Array) is by far the largest project of current ground-based observational facilities in astronomy and astrophysics. It is built and operated in the world-wide cooperation (ESO, NRAO, NAOJ) at altitude of 5000m in the desert of Atacama, Chile. Because of its unprecedented capabilities, ALMA is considered as a cutting-edge research device in astrophysics with potential for many breakthrough discoveries in the next decade and beyond. In spite it is not exclusively solar-research dedicated instrument, science observations of the Sun are now possible and has recently started in the observing Cycle 4 (2016-2017). In order to facilitate user access to this top-class, but at the same moment very complicated device to researchers lacking technical expertise, a network of three ALMA Regional Centers (ARCs) has been formed in Europe, North America, and East Asia as a user-support infrastructure and interface between the observatory and users community. After short introduction to ALMA the roles of ARCs and hint how to utilize their services will be presented, with emphasis to the specific (and in Europe unique) mission of the Czech ARC node in solar research with ALMA. Finally, peculiarities of solar observations that demanded the development of the specific Solar ALMA Observing Modes will be discuss

Dual interface gratings design for absorption enhancement in thin crystalline silicon solar cells

NASA Astrophysics Data System (ADS)

Zhang, Jinqiannan; Yu, Zhongyuan; Liu, Yumin; Chai, Hongyu; Hao, Jing; Ye, Han

2017-09-01

We numerically study and analyze the light absorption enhancement in thin crystalline silicon solar cell with dual interface gratings. The structure combines the front dielectric nanowalls and the sinusoidal plasmonic grating at back reflector. We show that having specific interfaces with well-chosen period, fill factor and height can allow more efficient dielectric and plasmonic modes coupling into active layer and can improve the solar cell performance. For 1 μm active layer case, the optimal result for the proposed structure achieves short-circuit current of 23.6 mA/cm2, which performs over 50% better than flat solar cell structure, the short-circuit current of which is 15.5 mA/cm2. In addition, the active layer thickness and angular analysis show that the proposed structure maintains its advantage over flat structure.

Light trapping in thin-film solar cells with randomly rough and hybrid textures.

PubMed

Kowalczewski, Piotr; Liscidini, Marco; Andreani, Lucio Claudio

2013-09-09

We study light-trapping in thin-film silicon solar cells with rough interfaces. We consider solar cells made of different materials (c-Si and μc-Si) to investigate the role of size and nature (direct/indirect) of the energy band gap in light trapping. By means of rigorous calculations we demonstrate that the Lambertian Limit of absorption can be obtained in a structure with an optimized rough interface. We gain insight into the light trapping mechanisms by analysing the optical properties of rough interfaces in terms of Angular Intensity Distribution (AID) and haze. Finally, we show the benefits of merging ordered and disordered photonic structures for light trapping by studying a hybrid interface, which is a combination of a rough interface and a diffraction grating. This approach gives a significant absorption enhancement for a roughness with a modest size of spatial features, assuring good electrical properties of the interface. All the structures presented in this work are compatible with present-day technologies, giving recent progress in fabrication of thin monocrystalline silicon films and nanoimprint lithography.

NASA's Best-Observed X-Class Flare of All Time

NASA Image and Video Library

2014-05-07

Zoom in on the flare in ultraviolet (SDO/AIA), X-rays (Hinode) and gamma-rays (RHESSI) -- On March 29, 2014 the sun released an X-class flare. It was observed by NASA's Interface Region Imaging Spectrograph, or IRIS; NASA's Solar Dynamics Observatory, or SDO; NASA's Reuven Ramaty High Energy Solar Spectroscopic Imager, or RHESSI; the Japanese Aerospace Exploration Agency's Hinode; and the National Solar Observatory's Dunn Solar Telescope located at Sacramento Peak in New Mexico. To have a record of such an intense flare from so many observatories is unprecedented. Such research can help scientists better understand what catalyst sets off these large explosions on the sun. Perhaps we may even some day be able to predict their onset and forewarn of the radio blackouts solar flares can cause near Earth - blackouts that can interfere with airplane, ship and military communications. Read more: 1.usa.gov/1kMDQbO Join our Google+ Hangout on May 8 at 2:30pm EST: go.nasa.gov/1mwbBEZ Credit: NASA Goddard NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

NASA's Best-Observed X-Class Flare of All Time

NASA Image and Video Library

2014-05-07

A combination of many (but not all) of the datasets which observed this flare. -- On March 29, 2014 the sun released an X-class flare. It was observed by NASA's Interface Region Imaging Spectrograph, or IRIS; NASA's Solar Dynamics Observatory, or SDO; NASA's Reuven Ramaty High Energy Solar Spectroscopic Imager, or RHESSI; the Japanese Aerospace Exploration Agency's Hinode; and the National Solar Observatory's Dunn Solar Telescope located at Sacramento Peak in New Mexico. To have a record of such an intense flare from so many observatories is unprecedented. Such research can help scientists better understand what catalyst sets off these large explosions on the sun. Perhaps we may even some day be able to predict their onset and forewarn of the radio blackouts solar flares can cause near Earth - blackouts that can interfere with airplane, ship and military communications. Read more: 1.usa.gov/1kMDQbO Join our Google+ Hangout on May 8 at 2:30pm EST: go.nasa.gov/1mwbBEZ Credit: NASA Goddard NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Solar Irradiance Data Products at the LASP Interactive Solar IRradiance Datacenter (LISIRD)

NASA Astrophysics Data System (ADS)

Lindholm, D. M.; Ware DeWolfe, A.; Wilson, A.; Pankratz, C. K.; Snow, M. A.; Woods, T. N.

2011-12-01

The Laboratory for Atmospheric and Space Physics (LASP) has developed the LASP Interactive Solar IRradiance Datacenter (LISIRD, http://lasp.colorado.edu/lisird/) web site to provide access to a comprehensive set of solar irradiance measurements and related datasets. Current data holdings include products from NASA missions SORCE, UARS, SME, and TIMED-SEE. The data provided covers a wavelength range from soft X-ray (XUV) at 0.1 nm up to the near infrared (NIR) at 2400 nm, as well as Total Solar Irradiance (TSI). Other datasets include solar indices, spectral and flare models, solar images, and more. The LISIRD web site features updated plotting, browsing, and download capabilities enabled by dygraphs, JavaScript, and Ajax calls to the LASP Time Series Server (LaTiS). In addition to the web browser interface, most of the LISIRD datasets can be accessed via the LaTiS web service interface that supports the OPeNDAP standard. OPeNDAP clients and other programming APIs are available for making requests that subset, aggregate, or filter data on the server before it is transported to the user. This poster provides an overview of the LISIRD system, summarizes the datasets currently available, and provides details on how to access solar irradiance data products through LISIRD's interfaces.

Modelling heterogeneous interfaces for solar water splitting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pham, Tuan Anh; Ping, Yuan; Galli, Giulia

2017-01-09

The generation of hydrogen from water and sunlight others a promising approach for producing scalable and sustainable carbon-free energy. The key of a successful solar-to-fuel technology is the design of efficient, long-lasting and low-cost photoelectrochemical cells, which are responsible for absorbing sunlight and driving water splitting reactions. To this end, a detailed understanding and control of heterogeneous interfaces between photoabsorbers, electrolytes and catalysts present in photoelectrochemical cells is essential. Here we review recent progress and open challenges in predicting physicochemical properties of heterogeneous interfaces for solar water splitting applications using first-principles-based approaches, and highlights the key role of these calculationsmore » in interpreting increasingly complex experiments.« less

FUSE spectra of Lyman series emissions from the interplanetary medium

NASA Astrophysics Data System (ADS)

Clarke, John

Neutral atoms from the local ISM flow into the solar system producing diffuse emissions through resonant scattering of solar emissions. This wind contains the velocity distribution of the local ISM, plus modifications by solar gravity and radiation pressure near the Sun. In addition, the H atom motions are modified by charge exchange collisions with fast protons in the heliospheric interface region, while He atoms are little affected by charge exchange. Recent observations of the He and H flows in the solar system suggest that the He velocity of 26 km s-1 is that of the local ISM cloud, while the lower H velocity of 18-21 km s-1 and greatly increased velocity dispersion in the flow direction are due to an interface modification of the H flow. Remote observations of the H flow thereby provide a method to remotely study the heliospheric interface. The H flow has been studied from H Lyα line profiles at high spectral resolution observed by Copernicus, IUE, and HST, using the Earth orbital motion to Doppler shift the ISM from the geocoronal emission. One serious ambiguity in the interpretation of these data results from the optically thick Lyα emission, leading to uncertainties in derived values of the H density. Using FUSE to observe the brightness and line profile of the optically thin H Lyβ line, close in time to SOHO observations of the Lyα emission, we can determine accurately the optical depth and density n(H) along lines of sight upwind, downwind, and cross-flow. Comparing n(H) with the heliospheric helium density, and with the interstellar cloud HI/HeI ratio measured recently by the EUVE, will give the fraction of H atoms removed by charge exchange at the entrance to the heliosphere, and then the Local Cloud (or ambient ISM) electron density which governs the size of the heliosphere. We request FUSE sky aperture spectra in the two narrow science apertures obtained during other pointed observations, through cooperation in scheduling pointed observations in the correct look directions at the proper times of year.

SEPS mission and system integration/interface requirements for the space transportation system. [Solar Electric Propulsion System

NASA Technical Reports Server (NTRS)

Cork, M. J.; Barnett, P. M.; Shaffer, J., Jr.; Doran, B. J.

1979-01-01

Earth escape mission requirements on Solar Electric Propulsion System (SEPS), and the interface definition and planned integration between SEPS, user spacecraft, and other elements of the STS. Emphasis is placed on the Comet rendezvous mission, scheduled to be the first SEPS user. Interactive SEPS interface characteristics with spacecraft and mission, as well as the multiple organizations and inter-related development schedules required to integrate the SEPS with spacecraft and STS, require early attention to definition of interfaces in order to assure a successful path to the first SEPS launch in July 1985

Capturing Change: Integrating Art and Science

NASA Astrophysics Data System (ADS)

Gillerman, J.

2011-12-01

The evolving capabilities of interactive media have broadened the potential, and the challenges, of sharing scientific knowledge. From video capture to mobile devices, new technologies have enabled artists to tackle previously demanding or out-of-reach topics and new avenues of dissemination of both art and science. These changes and capabilities affect not only the context and possibilities of scientific data collection, but also how information is presented and communicated innovatively to the public. When recording video of science material whether it is of a Ridley Sea Turtle laying eggs on a beach in Costa Rica, an active lava flow from the volcano Kilauea in Hawaii, or solar eclipses in remote locations around the world, one has to be prepared technically and artistically, not to mention patient in specialized and/or challenging conditions to capture video that satisfies the scientific and artistic imagination. This presentation will include material from varied natural phenomena, creative interfacing in a multimedia context integrating art, science, culture and technology to reach a broad and diverse public, and teaching the integration of art and science through varied art media. (http://www.vipervertex.com).

Promoting Charge Separation and Injection by Optimizing the Interfaces of GaN:ZnO Photoanode for Efficient Solar Water Oxidation.

PubMed

Wang, Zhiliang; Zong, Xu; Gao, Yuying; Han, Jingfeng; Xu, Zhiqiang; Li, Zheng; Ding, Chunmei; Wang, Shengyang; Li, Can

2017-09-13

Photoelectrochemical water splitting provides an attractive way to store solar energy in molecular hydrogen as a kind of sustainable fuel. To achieve high solar conversion efficiency, the most stringent criteria are effective charge separation and injection in electrodes. Herein, efficient photoelectrochemical water oxidation is realized by optimizing charge separation and surface charge transfer of GaN:ZnO photoanode. The charge separation can be greatly improved through modified moisture-assisted nitridation and HCl acid treatment, by which the interfaces in GaN:ZnO solid solution particles are optimized and recombination centers existing at the interfaces are depressed in GaN:ZnO photoanode. Moreover, a multimetal phosphide of NiCoFeP was employed as water oxidation cocatalyst to improve the charge injection at the photoanode/electrolyte interface. Consequently, it significantly decreases the overpotential and brings the photocurrent to a benchmark of 3.9 mA cm -2 at 1.23 V vs RHE and a solar conversion efficiency over 1% was obtained.

Designing novel thin film polycrystalline solar cells for high efficiency: sandwich CIGS and heterojunction perovskite

NASA Astrophysics Data System (ADS)

Wang, Tianyue; Chen, Jiewei; Wu, Gaoxiang; Song, Dandan; Li, Meicheng

2017-01-01

Heterojunction and sandwich architectures are two new-type structures with great potential for solar cells. Specifically, the heterojunction structure possesses the advantages of efficient charge separation but suffers from band offset and large interface recombination; the sandwich configuration is favorable for transferring carriers but requires complex fabrication process. Here, we have designed two thin-film polycrystalline solar cells with novel structures: sandwich CIGS and heterojunction perovskite, referring to the advantages of the architectures of sandwich perovskite (standard) and heterojunction CIGS (standard) solar cells, respectively. A reliable simulation software wxAMPS is used to investigate their inherent characteristics with variation of the thickness and doping density of absorber layer. The results reveal that sandwich CIGS solar cell is able to exhibit an optimized efficiency of 20.7%, which is much higher than the standard heterojunction CIGS structure (18.48%). The heterojunction perovskite solar cell can be more efficient employing thick and doped perovskite films (16.9%) than these typically utilizing thin and weak-doping/intrinsic perovskite films (9.6%). This concept of structure modulation proves to be useful and can be applicable for other solar cells. Project supported by the National High-Tech R&D Program of China (No. 2015AA034601), the National Natural Science Foundation of China (Nos. 91333122, 61204064, 51202067, 51372082, 51402106, 11504107), the Ph.D. Programs Foundation of Ministry of Education of China (Nos. 20120036120006, 20130036110012), the Par-Eu Scholars Program, and the Fundamental Research Funds for the Central Universities.

Development of Efficient and Stable Inverted Bulk Heterojunction (BHJ) Solar Cells Using Different Metal Oxide Interfaces

PubMed Central

Litzov, Ivan; Brabec, Christoph J.

2013-01-01

Solution-processed inverted bulk heterojunction (BHJ) solar cells have gained much more attention during the last decade, because of their significantly better environmental stability compared to the normal architecture BHJ solar cells. Transparent metal oxides (MeOx) play an important role as the dominant class for solution-processed interface materials in this development, due to their excellent optical transparency, their relatively high electrical conductivity and their tunable work function. This article reviews the advantages and disadvantages of the most common synthesis methods used for the wet chemical preparation of the most relevant n-type- and p-type-like MeOx interface materials consisting of binary compounds AxBy. Their performance for applications as electron transport/extraction layers (ETL/EEL) and as hole transport/extraction layers (HTL/HEL) in inverted BHJ solar cells will be reviewed and discussed. PMID:28788423

Development of Efficient and Stable Inverted Bulk Heterojunction (BHJ) Solar Cells Using Different Metal Oxide Interfaces.

PubMed

Litzov, Ivan; Brabec, Christoph J

2013-12-10

Solution-processed inverted bulk heterojunction (BHJ) solar cells have gained much more attention during the last decade, because of their significantly better environmental stability compared to the normal architecture BHJ solar cells. Transparent metal oxides (MeO x ) play an important role as the dominant class for solution-processed interface materials in this development, due to their excellent optical transparency, their relatively high electrical conductivity and their tunable work function. This article reviews the advantages and disadvantages of the most common synthesis methods used for the wet chemical preparation of the most relevant n -type- and p -type-like MeO x interface materials consisting of binary compounds A x B y . Their performance for applications as electron transport/extraction layers (ETL/EEL) and as hole transport/extraction layers (HTL/HEL) in inverted BHJ solar cells will be reviewed and discussed.

APT mass spectrometry and SEM data for CdTe solar cells

DOE PAGES

Li, Chen; Paudel, Naba R.; Yan, Yanfa; ...

2016-03-16

Atom probe tomography (APT) data acquired from a CAMECA LEAP 4000 XHR for the CdS/CdTe interface for a non-CdCl 2 treated CdTe solar cell as well as the mass spectrum of an APT data set including a GB in a CdCl 2-treated CdTe solar cell are presented. Scanning electron microscopy (SEM) data showing the evolution of sample preparation for APT and scanning transmission electron microscopy (STEM) electron beam induced current (EBIC) are also presented. As a result, these data show mass spectrometry peak decomposition of Cu and Te within an APT dataset, the CdS/CdTe interface of an untreated CdTe solarmore » cell, preparation of APT needles from the CdS/CdTe interface in superstrate grown CdTe solar cells, and the preparation of a cross-sectional STEM EBIC sample.« less

Influence of hole transport material/metal contact interface on perovskite solar cells

NASA Astrophysics Data System (ADS)

Lei, Lei; Zhang, Shude; Yang, Songwang; Li, Xiaomin; Yu, Yu; Wei, Qingzhu; Ni, Zhichun; Li, Ming

2018-06-01

Interfaces have a significant impact on the performance of perovskite solar cells. This work investigated the influence of hole transport material/metal contact interface on photovoltaic behaviours of perovskite solar devices. Different hole material/metal contact interfaces were obtained by depositing the metal under different conditions. High incident kinetic energy metal particles were proved to penetrate and embed into the hole transport material. These isolated metal particles in hole transport materials capture holes and increase the apparent carrier transport resistance of the hole transport layer. Sample temperature was found to be of great significance in metal deposition. Since metal vapour has a high temperature, the deposition process accumulated a large amount of heat. The heat evaporated the additives in the hole transport layer and decreased the hole conductivity. On the other hand, high temperature may cause iodization of the metal contact.

Influence of hole transport material/metal contact interface on perovskite solar cells.

PubMed

Lei, Lei; Zhang, Shude; Yang, Songwang; Li, Xiaomin; Yu, Yu; Wei, Qingzhu; Ni, Zhichun; Li, Ming

2018-06-22

Interfaces have a significant impact on the performance of perovskite solar cells. This work investigated the influence of hole transport material/metal contact interface on photovoltaic behaviours of perovskite solar devices. Different hole material/metal contact interfaces were obtained by depositing the metal under different conditions. High incident kinetic energy metal particles were proved to penetrate and embed into the hole transport material. These isolated metal particles in hole transport materials capture holes and increase the apparent carrier transport resistance of the hole transport layer. Sample temperature was found to be of great significance in metal deposition. Since metal vapour has a high temperature, the deposition process accumulated a large amount of heat. The heat evaporated the additives in the hole transport layer and decreased the hole conductivity. On the other hand, high temperature may cause iodization of the metal contact.

Interface Engineering of Organic Schottky Barrier Solar Cells and Its Application in Enhancing Performances of Planar Heterojunction Solar Cells

NASA Astrophysics Data System (ADS)

Jin, Fangming; Su, Zisheng; Chu, Bei; Cheng, Pengfei; Wang, Junbo; Zhao, Haifeng; Gao, Yuan; Yan, Xingwu; Li, Wenlian

2016-05-01

In this work, we describe the performance of organic Schottky barrier solar cells with the structure of ITO/molybdenum oxide (MoOx)/boron subphthalocyanine chloride (SubPc)/bathophenanthroline (BPhen)/Al. The SubPc-based Schottky barrier solar cells exhibited a short-circuit current density (Jsc) of 2.59 mA/cm2, an open-circuit voltage (Voc) of 1.06 V, and a power conversion efficiency (PCE) of 0.82% under simulated AM1.5 G solar illumination at 100 mW/cm2. Device performance was substantially enhanced by simply inserting thin organic hole transport material into the interface of MoOx and SubPc. The optimized devices realized a 180% increase in PCE of 2.30% and a peak Voc as high as 1.45 V was observed. We found that the improvement is due to the exciton and electron blocking effect of the interlayer and its thickness plays a vital role in balancing charge separation and suppressing quenching effect. Moreover, applying such interface engineering into MoOx/SubPc/C60 based planar heterojunction cells substantially enhanced the PCE of the device by 44%, from 3.48% to 5.03%. Finally, we also investigated the requirements of the interface material for Schottky barrier modification.

Interface Engineering of Organic Schottky Barrier Solar Cells and Its Application in Enhancing Performances of Planar Heterojunction Solar Cells.

PubMed

Jin, Fangming; Su, Zisheng; Chu, Bei; Cheng, Pengfei; Wang, Junbo; Zhao, Haifeng; Gao, Yuan; Yan, Xingwu; Li, Wenlian

2016-05-17

In this work, we describe the performance of organic Schottky barrier solar cells with the structure of ITO/molybdenum oxide (MoOx)/boron subphthalocyanine chloride (SubPc)/bathophenanthroline (BPhen)/Al. The SubPc-based Schottky barrier solar cells exhibited a short-circuit current density (Jsc) of 2.59 mA/cm(2), an open-circuit voltage (Voc) of 1.06 V, and a power conversion efficiency (PCE) of 0.82% under simulated AM1.5 G solar illumination at 100 mW/cm(2). Device performance was substantially enhanced by simply inserting thin organic hole transport material into the interface of MoOx and SubPc. The optimized devices realized a 180% increase in PCE of 2.30% and a peak Voc as high as 1.45 V was observed. We found that the improvement is due to the exciton and electron blocking effect of the interlayer and its thickness plays a vital role in balancing charge separation and suppressing quenching effect. Moreover, applying such interface engineering into MoOx/SubPc/C60 based planar heterojunction cells substantially enhanced the PCE of the device by 44%, from 3.48% to 5.03%. Finally, we also investigated the requirements of the interface material for Schottky barrier modification.

Biological components and bioelectronic interfaces of water splitting photoelectrodes for solar hydrogen production.

PubMed

Braun, Artur; Boudoire, Florent; Bora, Debajeet K; Faccio, Greta; Hu, Yelin; Kroll, Alexandra; Mun, Bongjin S; Wilson, Samuel T

2015-03-09

Artificial photosynthesis (AP) is inspired by photosynthesis in nature. In AP, solar hydrogen can be produced by water splitting in photoelectrochemical cells (PEC). The necessary photoelectrodes are inorganic semiconductors. Light-harvesting proteins and biocatalysts can be coupled with these photoelectrodes and thus form bioelectronic interfaces. We expand this concept toward PEC devices with vital bio-organic components and interfaces, and their integration into the built environment. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Combined soft and hard X-ray ambient pressure photoelectron spectroscopy studies of semiconductor/electrolyte interfaces

DOE PAGES

Starr, David E.; Favaro, Marco; Abdi, Fatwa F.; ...

2017-05-18

The development of solar fuel generating materials would greatly benefit from a molecular level understanding of the semiconductor/electrolyte interface and changes in the interface induced by an applied potential and illumination by solar light. Ambient pressure photoelectron spectroscopy techniques with both soft and hard X-rays, AP-XPS and AP-HAXPES respectively, have the potential to markedly contribute to this understanding. In this paper we initially provide two examples of current challenges in solar fuels material development that AP-XPS and AP-HAXPES can directly a ddress. This will be followed by a brief description of the distinguishing and complementary characteristics of soft and hardmore » X-ray AP-XPS and AP-HAXPES and best approaches to achieving monolayer sensitivity in solid/aqueous electrolyte studies. In particular we focus on the detection of surface adsorbed hydroxyl groups in the presence of aqueous hydroxide anions in the electrolyte, a common situation when investigating photoanodes for solar fuel generating applications. Finally, the article concludes by providing an example of a combined AP-XPS and AP-HAXPES study of a semiconductor/aqueous electrolyte interface currently used in water splitting devices specifically the BiVO 4/aqueous potassium phosphate electrolyte interface.« less

Chairmanship of the Neptune/Pluto outer planets science working group

NASA Astrophysics Data System (ADS)

Stern, S. Alan

1993-11-01

The Outer Planets Science Working Group (OPSWG) is the NASA Solar System Exploration Division (SSED) scientific steering committee for the Outer Solar System missions. OPSWG consists of 19 members and is chaired by Dr. S. Alan Stern. This proposal summarizes the FY93 activities of OPSWG, describes a set of objectives for OPSWG in FY94, and outlines the SWG's activities for FY95. As chair of OPSWG, Dr. Stern will be responsible for: organizing priorities, setting agendas, conducting meetings of the Outer Planets SWG; reporting the results of OPSWG's work to SSED; supporting those activities relating to OPSWG work, such as briefings to the SSES, COMPLEX, and OSS; supporting the JPL/SAIC Pluto study team; and other tasks requested by SSED. As the Scientific Working Group (SWG) for Jupiter and the planets beyond, OPSWG is the SSED SWG chartered to study and develop mission plans for all missions to the giant planets, Pluto, and other distant objects in the remote outer solar system. In that role, OPSWG is responsible for: defining and prioritizing scientific objectives for missions to these bodies; defining and documenting the scientific goals and rationale behind such missions; defining and prioritizing the datasets to be obtained in these missions; defining and prioritizing measurement objectives for these missions; defining and documenting the scientific rationale for strawman instrument payloads; defining and prioritizing the scientific requirements for orbital tour and flyby encounter trajectories; defining cruise science opportunities plan; providing technical feedback to JPL and SSED on the scientific capabilities of engineering studies for these missions; providing documentation to SSED concerning the scientific goals, objectives, and rationale for the mission; interfacing with other SSED and OSS committees at the request of SSED's Director or those committee chairs; providing input to SSED concerning the structure and content of the Announcement of Opportunity for payload and scientific team selection for such missions; and providing other technical or programmatic inputs concerning outer solar system missions at the request of the Director of SSED.

Chairmanship of the Neptune/Pluto outer planets science working group

NASA Technical Reports Server (NTRS)

Stern, S. Alan

1993-01-01

The Outer Planets Science Working Group (OPSWG) is the NASA Solar System Exploration Division (SSED) scientific steering committee for the Outer Solar System missions. OPSWG consists of 19 members and is chaired by Dr. S. Alan Stern. This proposal summarizes the FY93 activities of OPSWG, describes a set of objectives for OPSWG in FY94, and outlines the SWG's activities for FY95. As chair of OPSWG, Dr. Stern will be responsible for: organizing priorities, setting agendas, conducting meetings of the Outer Planets SWG; reporting the results of OPSWG's work to SSED; supporting those activities relating to OPSWG work, such as briefings to the SSES, COMPLEX, and OSS; supporting the JPL/SAIC Pluto study team; and other tasks requested by SSED. As the Scientific Working Group (SWG) for Jupiter and the planets beyond, OPSWG is the SSED SWG chartered to study and develop mission plans for all missions to the giant planets, Pluto, and other distant objects in the remote outer solar system. In that role, OPSWG is responsible for: defining and prioritizing scientific objectives for missions to these bodies; defining and documenting the scientific goals and rationale behind such missions; defining and prioritizing the datasets to be obtained in these missions; defining and prioritizing measurement objectives for these missions; defining and documenting the scientific rationale for strawman instrument payloads; defining and prioritizing the scientific requirements for orbital tour and flyby encounter trajectories; defining cruise science opportunities plan; providing technical feedback to JPL and SSED on the scientific capabilities of engineering studies for these missions; providing documentation to SSED concerning the scientific goals, objectives, and rationale for the mission; interfacing with other SSED and OSS committees at the request of SSED's Director or those committee chairs; providing input to SSED concerning the structure and content of the Announcement of Opportunity for payload and scientific team selection for such missions; and providing other technical or programmatic inputs concerning outer solar system missions at the request of the Director of SSED.

Effect of Interfacial Molecular Orientation on Power Conversion Efficiency of Perovskite Solar Cells.

PubMed

Xiao, Minyu; Joglekar, Suneel; Zhang, Xiaoxian; Jasensky, Joshua; Ma, Jialiu; Cui, Qingyu; Guo, L Jay; Chen, Zhan

2017-03-08

A wide variety of charge carrier dynamics, such as transport, separation, and extraction, occur at the interfaces of planar heterojunction solar cells. Such factors can affect the overall device performance. Therefore, understanding the buried interfacial molecular structure in various devices and the correlation between interfacial structure and function has become increasingly important. Current characterization techniques for thin films such as X-ray diffraction, cross section scanning electronmicroscopy, and UV-visible absorption spectroscopy are unable to provide the needed molecular structural information at buried interfaces. In this study, by controlling the structure of the hole transport layer (HTL) in a perovskite solar cell and applying a surface/interface-sensitive nonlinear vibrational spectroscopic technique (sum frequency generation vibrational spectroscopy (SFG)), we successfully probed the molecular structure at the buried interface and correlated its structural characteristics to solar cell performance. Here, an edge-on (normal to the interface) polythiophene (PT) interfacial molecular orientation at the buried perovskite (photoactive layer)/PT (HTL) interface showed more than two times the power conversion efficiency (PCE) of a lying down (tangential) PT interfacial orientation. The difference in interfacial molecular structure was achieved by altering the alkyl side chain length of the PT derivatives, where PT with a shorter alkyl side chain showed an edge-on interfacial orientation with a higher PCE than that of PT with a longer alkyl side chain. With similar band gap alignment and bulk structure within the PT layer, it is believed that the interfacial molecular structural variation (i.e., the orientation difference) of the various PT derivatives is the underlying cause of the difference in perovskite solar cell PCE.

Accessing the band alignment in high efficiency Cu(In,Ga)(Se,S)2 (CIGSSe) solar cells with an InxSy:Na buffer based on temperature dependent measurements and simulations

NASA Astrophysics Data System (ADS)

Schoneberg, Johannes; Ohland, Jörg; Eraerds, Patrick; Dalibor, Thomas; Parisi, Jürgen; Richter, Michael

2018-04-01

We present a one-dimensional simulation model for high efficiency Cu(In,Ga)(Se,S)2 solar cells with a novel band alignment at the hetero-junction. The simulation study is based on new findings about the doping concentration of the InxSy:Na buffer and i-ZnO layers as well as comprehensive solar cell characterization by means of capacitance, current voltage, and external quantum efficiency measurements. The simulation results show good agreement with the experimental data over a broad temperature range, suggesting the simulation model with an interface-near region (INR) of approximately 100 nm around the buffer/absorber interface that is of great importance for the solar cell performance. The INR exhibits an inhomogeneous doping and defect density profile as well as interface traps at the i-layer/buffer and buffer/absorber interfaces. These crucial parameters could be accessed via their opposing behavior on the simulative reconstruction of different measurement characteristics. In this work, we emphasize the necessity to reconstruct the results of a set of experimental methods by means of simulation to find the most appropriate model for the solar cell. Lowly doped buffer and intrinsic window layers in combination with a high space charge at the front of the absorber lead to a novel band alignment in the simulated band structure of the solar cell. The presented insights may guide the strategy of further solar cell optimization including (alkali-) post deposition treatments.

A computational study of photo-induced electron transfer rate constants in subphthalocyanine/C60 organic photovoltaic materials via Fermi's golden rule

NASA Astrophysics Data System (ADS)

Lee, Myeong H.; Dunietz, Barry D.; Geva, Eitan

2014-03-01

We present a methodology to obtain the photo-induced electron transfer rate constant in organic photovoltaic (OPV) materials within the framework of Fermi's golden rule, using inputs obtained from first-principles electronic structure calculation. Within this approach, the nuclear vibrational modes are treated quantum-mechanically and a short-time approximation is avoided in contrast to the classical Marcus theory where these modes are treated classically within the high-temperature and short-time limits. We demonstrate our methodology on boron-subphthalocyanine-chloride/C60 OPV system to determine the rate constants of electron transfer and electron recombination processes upon photo-excitation. We consider two representative donor/acceptor interface configurations to investigate the effect of interface configuration on the charge transfer characteristics of OPV materials. In addition, we determine the time scale of excited states population by employing a master equation after obtaining the rate constants for all accessible electronic transitions. This work is pursued as part of the Center for Solar and Thermal Energy Conversion, an Energy Frontier Research Center funded by the US Department of Energy Office of Science, Office of Basic Energy Sciences under 390 Award No. DE-SC0000957.

Floating growth of large-scale freestanding TiO2 nanorod films at the gas-liquid interface for additive-free Li-ion battery applications.

PubMed

Xia, Hua-Rong; Li, Jia; Peng, Chen; Sun, Wen-Tao; Li, Long-Wei; Peng, Lian-Mao

2014-10-22

The floating growth process of large-scale freestanding TiO2 nanorod films at the gas-liquid interface was investigated. On the basis of the experiments, a self-templated growth scenario was developed to account for the self-assembly process. In the scenario, titanium complexes function not only as the Ti source for the growth of TiO2 but also as a soft template provider for the floating growth. According to the scenario, several new recipes of preparing freestanding TiO2 nanorod films at the gas-liquid interface were developed. The freestanding film was applied to a lithium ion battery as a binder-free and conducting agent-free anode, and good cyclability was obtained. This work may pave a new way to floating and freestanding TiO2 and other semiconductor materials, which has great potential not only in basic science but also in the applications such as materials engineering, Li-ion battery, photocatalyst, dye-sensitized solar cell, and flexible electronics.

Understanding Non-Equilibrium Charge Transport and Rectification at Chromophore/Metal Interfaces

NASA Astrophysics Data System (ADS)

Darancet, Pierre

Understanding non-equilibrium charge and energy transport across nanoscale interfaces is central to developing an intuitive picture of fundamental processes in solar energy conversion applications. In this talk, I will discuss our theoretical studies of finite-bias transport at organic/metal interfaces. First, I will show how the finite-bias electronic structure of such systems can be quantitatively described using density functional theory in conjunction with simple models of non-local correlations and bias-induced Stark effects.. Using these methods, I will discuss the conditions of emergence of highly non-linear current-voltage characteristics in bilayers made of prototypical organic materials, and their implications in the context of hole- and electron-blocking layers in organic photovoltaic. In particular, I will show how the use of strongly-hybridized, fullerene-coated metallic surfaces as electrodes is a viable route to maximizing the diodic behavior and electrical functionality of molecular components. The submitted manuscript has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (Argonne). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357.

Coordinated science with the Solar Orbiter, Solar Probe Plus, Interhelioprobe and SPORT missions

NASA Astrophysics Data System (ADS)

Maksimovic, Milan; Vourlidas, Angelos; Zimovets, Ivan; Velli, Marco; Zhukov, Andrei; Kuznetsov, Vladimir; Liu, Ying; Bale, Stuart; Ming, Xiong

The concurrent science operations of the ESA Solar Orbiter (SO), NASA Solar Probe Plus (SPP), Russian Interhelioprobe (IHP) and Chinese SPORT missions will offer a truly unique epoch in heliospheric science. While each mission will achieve its own important science objectives, taken together the four missions will be capable of doing the multi-point measurements required to address many problems in Heliophysics such as the coronal origin of the solar wind plasma and magnetic field or the way the Solar transients drive the heliospheric variability. In this presentation, we discuss the capabilities of the four missions and the Science synergy that will be realized by concurrent operations

Nanoimprint-Transfer-Patterned Solids Enhance Light Absorption in Colloidal Quantum Dot Solar Cells.

PubMed

Kim, Younghoon; Bicanic, Kristopher; Tan, Hairen; Ouellette, Olivier; Sutherland, Brandon R; García de Arquer, F Pelayo; Jo, Jea Woong; Liu, Mengxia; Sun, Bin; Liu, Min; Hoogland, Sjoerd; Sargent, Edward H

2017-04-12

Colloidal quantum dot (CQD) materials are of interest in thin-film solar cells due to their size-tunable bandgap and low-cost solution-processing. However, CQD solar cells suffer from inefficient charge extraction over the film thicknesses required for complete absorption of solar light. Here we show a new strategy to enhance light absorption in CQD solar cells by nanostructuring the CQD film itself at the back interface. We use two-dimensional finite-difference time-domain (FDTD) simulations to study quantitatively the light absorption enhancement in nanostructured back interfaces in CQD solar cells. We implement this experimentally by demonstrating a nanoimprint-transfer-patterning (NTP) process for the fabrication of nanostructured CQD solids with highly ordered patterns. We show that this approach enables a boost in the power conversion efficiency in CQD solar cells primarily due to an increase in short-circuit current density as a result of enhanced absorption through light-trapping.

MHD modelling of the heliospheric interface

NASA Astrophysics Data System (ADS)

Ratkiewicz, R.

The thin layer approximation (TLA) is used to ascertain the effect of the IMF on the heliospheric interface. The TLA approach can be used in considering properties of the solar wind termination shock, since by definition both curves are close to each other. Good agreement is obtained with previous predictions of the solar wind termination shock's shape and distance.

Toward Improved Lifetimes of Organic Solar Cells under Thermal Stress: Substrate-Dependent Morphological Stability of PCDTBT:PCBM Films and Devices.

PubMed

Li, Zhe; Ho Chiu, Kar; Shahid Ashraf, Raja; Fearn, Sarah; Dattani, Rajeev; Cheng Wong, Him; Tan, Ching-Hong; Wu, Jiaying; Cabral, João T; Durrant, James R

2015-10-15

Morphological stability is a key requirement for outdoor operation of organic solar cells. We demonstrate that morphological stability and lifetime of polymer/fullerene based solar cells under thermal stress depend strongly on the substrate interface on which the active layer is deposited. In particular, we find that the stability of benchmark PCDTBT/PCBM solar cells under modest thermal stress is substantially increased in inverted solar cells employing a ZnO substrate compared to conventional devices employing a PSS substrate. This improved stability is observed to correlate with PCBM nucleation at the 50 nm scale, which is shown to be strongly influenced by different substrate interfaces. Employing this approach, we demonstrate remarkable thermal stability for inverted PCDTBT:PC70BM devices on ZnO substrates, with negligible (<2%) loss of power conversion efficiency over 160 h under 85 °C thermal stress and minimal thermally induced "burn-in" effect. We thus conclude that inverted organic solar cells, in addition to showing improved environmental stability against ambient humidity exposure as widely reported previously, can also demonstrate enhanced morphological stability. As such we show that the choice of suitable substrate interfaces may be a key factor in achieving prolonged lifetimes for organic solar cells under thermal stress conditions.

Role of charge separation mechanism and local disorder at hybrid solar cell interfaces

NASA Astrophysics Data System (ADS)

Ehrenreich, Philipp; Pfadler, Thomas; Paquin, Francis; Dion-Bertrand, Laura-Isabelle; Paré-Labrosse, Olivier; Silva, Carlos; Weickert, Jonas; Schmidt-Mende, Lukas

2015-01-01

Dye-sensitized metal oxide polymer hybrid solar cells deliver a promising basis in organic solar cell development due to many conceptual advantages. Since the power conversion efficiency is still in a noncompetitive state, it has to be understood how the photocurrent contribution can be maximized (i.e., which dye-polymer properties are most beneficial for efficient charge generation in hybrid solar cells). By the comparison of three model systems for hybrid solar cells with Ti O2 -dye-polymer interfaces, this paper was aimed at elucidating the role of the exact mechanism of charge generation. In the exciton dissociation (ED) case, an exciton that is generated in the polymer is split at the dye-polymer interface. Alternatively, this exciton can be transferred to the dye via an energy transfer (ET), upon which charge separation occurs between dye and Ti O2 . For comparison, the third case is included in which the high lowest unoccupied molecular orbital of the dye does not allow exciton separation or ET from the dye to the polymer, so that the dye only is responsible for charge generation. To separate effects owing to differences in energy levels of the involved materials from the impact of local order and disorder in the polymer close to the interface, this paper further comprises a detailed analysis of the polymer crystallinity based on the H-aggregate model. While the massive impact of the poly(3-hexylthiophene) crystallinity on device function has been outlined for bare metal oxide-polymer interfaces, it has not been considered for hybrid solar cells with dye-sensitized Ti O2 . The results presented here indicate that all dye molecules in general influence the polymer morphology, which has to be taken into account for future optimization of hybrid solar cells. Apart from that, it can be suggested that ED on the polymer needs an additional driving force to work efficiently; thus, energy transfer seems to be currently the most promising strategy to increase the polymer photocurrent contribution.

Solar hydrogen production using epitaxial SrTiO 3 on a GaAs photovoltaic

DOE PAGES

Kornblum, L.; Fenning, D. P.; Faucher, J.; ...

2016-12-22

We demonstrate an oxide-stabilized III–V photoelectrode architecture for solar fuel production from water in neutral pH. For this tunable architecture we demonstrate 100% Faradaic efficiency for hydrogen evolution, and incident photon-to-current efficiencies (IPCE) exceeding 50%. High IPCE for hydrogen evolution is a consequence of the low-loss interface achieved via epitaxial growth of a thin oxide on a GaAs solar cell. Developing optimal energetic alignment across the interfaces of the photoelectrode using well-established III–V technology is key to obtaining high performance. This advance constitutes a critical milestone towards efficient, unassisted fuel production from solar energy.

Hydrophobic Polystyrene Passivation Layer for Simultaneously Improved Efficiency and Stability in Perovskite Solar Cells.

PubMed

Li, Minghua; Yan, Xiaoqin; Kang, Zhuo; Huan, Yahuan; Li, Yong; Zhang, Ruxiao; Zhang, Yue

2018-06-06

The major restraint for the commercialization of the high-performance hybrid metal halide perovskite solar cells is the long-term stability, especially at the infirm interface between the perovskite film and organic charge-transfer layer. Recently, engineering the interface between the perovskite and spiro-OMeTAD becomes an effective strategy to simultaneously improve the efficiency and stability in the perovskite solar cells. In this work, we demonstrated that introducing an interfacial polystyrene layer between the perovskite film and spiro-OMeTAD layer can effectively improve the perovskite solar cells photovoltaic performance. The inserted polystyrene layer can passivate the interface traps and defects effectively and decrease the nonradiative recombination, leading to enhanced photoluminescence intensity and carrier lifetime, without compromising the carrier extraction and transfer. Under the optimized condition, the perovskite solar cells with the polystyrene layer achieve an enhanced average power efficiency of about 19.61% (20.46% of the best efficiency) from about 17.63% with negligible current density-voltage hysteresis. Moreover, the optimized perovskite solar cells with the hydrophobic polystyrene layer can maintain about 85% initial efficiency after 2 months storage in open air conditions without encapsulation.

Numerical study of metal oxide hetero-junction solar cells with defects and interface states

NASA Astrophysics Data System (ADS)

Zhu, Le; Shao, Guosheng; Luo, J. K.

2013-05-01

Further to our previous work on ideal metal oxide (MO) hetero-junction solar cells, a systematic simulation has been carried out to investigate the effects of defects and interface states on the cells. Two structures of the window/absorber (WA) and window/absorber/voltage-enhancer (WAV) were modelled with defect concentration, defect energy level, interface state (ISt) density and ISt energy level as parameters. The simulation showed that the defects in the window layer and the voltage-enhancer layer have very limited effects on the performance of the cells, but those in the absorption layer have profound effects on the cell performance. The interface states at the W/A interface have a limited effect on the performance even for a density up to 1013 cm-2, while those at the A/V interface cause the solar cell to deteriorate severely even at a low density of lower than 1 × 1011 cm-2. It also showed that the back surface field (BSF) induced by band gap off-set in the WAV structure loses its function when defects with a modest concentration exist in the absorption layer and does not improve the open voltage at all.

Energy level engineering in ternary organic solar cells: Evaluating exciton dissociation at organic semiconductor interfaces

NASA Astrophysics Data System (ADS)

Feron, Krishna; Thameel, Mahir N.; Al-Mudhaffer, Mohammed F.; Zhou, Xiaojing; Belcher, Warwick J.; Fell, Christopher J.; Dastoor, Paul C.

2017-03-01

Electronic energy level engineering, with the aim to improve the power conversion efficiency in ternary organic solar cells, is a complex problem since multiple charge transfer steps and exciton dissociation driving forces must be considered. Here, we examine exciton dissociation in the ternary system poly(3-hexylthiophene): [6,6]-phenyl-C61-butyric acid methyl ester:2,4-bis[4-(N,N-diisobutylamino)-2,6-dihydroxyphenyl] squaraine (P3HT:PCBM:DIBSq). Even though the energy level diagram suggests that exciton dissociation at the P3HT:DIBSq interface should be efficient, electron paramagnetic resonance and external quantum efficiency measurements of planar devices show that this interface is not capable of generating separated charge carriers. Efficient exciton dissociation is still realised via energy transfer, which transports excitons from the P3HT:DIBSq interface to the DIBSq:PCBM interface, where separated charge carriers can be generated efficiently. This work demonstrates that energy level diagrams alone cannot be relied upon to predict the exciton dissociation and charge separation capability of an organic semiconductor interface and that energy transfer relaxes the energy level constraints for optimised multi-component organic solar cells.

International Observe the Moon Night: A Worldwide Public Observing Event that Annually Engages Scientists, Educators, and Citizen Enthusiasts in NASA Science

NASA Astrophysics Data System (ADS)

Buxner, S.; Jones, A. P.; Bleacher, L.; Wasser, M. L.; Day, B. H.; Shaner, A. J.; Bakerman, M. N.; Joseph, E.

2017-12-01

International Observe the Moon Night (InOMN) is an annual worldwide event, held in the fall, that celebrates lunar and planetary science and exploration. InOMN is sponsored by NASA's Lunar Reconnaissance Orbiter (LRO) in collaboration with NASA's Solar System Exploration Research Virtual Institute (SSERVI), the NASA's Heliophysics Education Consortium, CosmoQuest, Night Sky Network, and Science Festival Alliance. Other key partners include the NASA Museum Alliance, Night Sky Network, and NASA Solar System Ambassadors. In 2017, InOMN will bring together thousands of people across the globe to observe and learn about the Moon and its connection to planetary science. We are partnering with the NASA Science Mission Directorate total solar eclipse team to highlight InOMN as an opportunity to harness and sustain the interest and momentum in space science and observation following the August 21st eclipse. This is part of a new partnership with the Sun-Earth Day team, through the Heliophysics Education Consortium, to better connect the two largest NASA-sponsored public engagement events, increase participation in both events, and share best practices in implementation and evaluation between the teams. Over 3,800 InOMN events have been registered between 2010 and 2016, engaging over 550,000 visitors worldwide. Most InOMN events are held in the United States, with strong representation from many other countries. InOMN events are evaluated to determine the value of the events and to allow us to improve the experience for event hosts and visitors. Our results show that InOMN events are hosted by scientists, educators, and citizen enthusiasts around the world who leverage InOMN to bring communities together, get visitors excited and learn about the Moon - and beyond, and share resources to extend engagement in lunar and planetary science and observation. Through InOMN, we annually provide resources such as event-specific Moon maps, presentations, advertising materials, and certificates of participation. Additionally, InOMN highlights partner resources such as online interfaces including Moon Trek (https://moontrek.jpl.nasa.gov) and CosmoQuest (https://cosmoquest.org/x/) to provide further opportunities to engage with NASA science. Learn more about InOMN at http://observethemoonnight.org.

An XML-based Generic Tool for Information Retrieval in Solar Databases

NASA Astrophysics Data System (ADS)

Scholl, Isabelle F.; Legay, Eric; Linsolas, Romain

This paper presents the current architecture of the `Solar Web Project' now in its development phase. This tool will provide scientists interested in solar data with a single web-based interface for browsing distributed and heterogeneous catalogs of solar observations. The main goal is to have a generic application that can be easily extended to new sets of data or to new missions with a low level of maintenance. It is developed with Java and XML is used as a powerful configuration language. The server, independent of any database scheme, can communicate with a client (the user interface) and several local or remote archive access systems (such as existing web pages, ftp sites or SQL databases). Archive access systems are externally described in XML files. The user interface is also dynamically generated from an XML file containing the window building rules and a simplified database description. This project is developed at MEDOC (Multi-Experiment Data and Operations Centre), located at the Institut d'Astrophysique Spatiale (Orsay, France). Successful tests have been conducted with other solar archive access systems.

Solar Week: Learning from Experience

NASA Astrophysics Data System (ADS)

Alexander, D.; Hauck, K.

2003-12-01

Solar Week is a week-long set of games and activities allowing students to interact directly with solar science and solar scientists. Solar Week was developed as a spin-off of the highly successful Yohkoh Public Outreach Project (YPOP). While YPOP provided access to solar images, movies and activities, the main goal of Solar Week was to enhance the participation of women, who are under-represented in the physical sciences. Solar Week achieves this by providing young women, primarily in grades 6-8, with access to role models in the sciences. The scientists participating in Solar Week are women from a variety of backgrounds and with a variety of scientific expertise. In this paper, our aim is to provide some insight into developing activity-based space science for the web and to discuss the lessons-learned from tailoring to a specific group of participants.

Increasing conversion efficiency of two-step photon up-conversion solar cell with a voltage booster hetero-interface.

PubMed

Asahi, Shigeo; Kusaki, Kazuki; Harada, Yukihiro; Kita, Takashi

2018-01-17

Development of high-efficiency solar cells is one of the attractive challenges in renewable energy technologies. Photon up-conversion can reduce the transmission loss and is one of the promising concepts which improve conversion efficiency. Here we present an analysis of the conversion efficiency, which can be increased by up-conversion in a single-junction solar cell with a hetero-interface that boosts the output voltage. We confirm that an increase in the quasi-Fermi gap and substantial photocurrent generation result in a high conversion efficiency.

Metal-organic frameworks at interfaces of hybrid perovskite solar cells for enhanced photovoltaic properties.

PubMed

Shen, Deli; Pang, Aiying; Li, Yafeng; Dou, Jie; Wei, Mingdeng

2018-01-31

In this study, metal-organic frameworks, as an interfacial layer, were introduced into perovskite solar cells (PSCs) for the first time. An interface modified with the metal-organic framework ZIF-8 efficiently enhanced perovskite crystallinity and grain sizes, and the photovoltaic performance of the PSCs was significantly improved, resulting in a maximum PCE of 16.99%.

Improved Work Function of Poly(3,4-ethylenedioxythiophene): Poly(styrenesulfonic acid) and its Effect on Hybrid Silicon/Organic Heterojunction Solar Cells.

PubMed

Shen, Xiaojuan; Chen, Ling; Pan, Jianmei; Hu, Yue; Li, Songjun; Zhao, Jie

2016-12-01

Hybrid silicon/organic solar cells have been recently extensively investigated due to their simple structure and low-cost fabrication process. However, the efficiency of the solar cells is greatly limited by the barrier height as well as the carrier recombination at the silicon/organic interface. In this work, hydrochloroplatinic acid (H 2 PtCl 6 ) is employed into the poly(3,4-ethlenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) solution, and the work function (WF) of the PEDOT:PSS layer has been successfully improved. Based on the Pt-modified PEDOT:PSS layer, the efficiency of the silicon/PEDOT:PSS cell can be increased to 11.46%, corresponding to ~20% enhancement to the one without platinum (Pt) modification. Theoretical and experimental results show that, when increasing the WF of the PEDO:PSS layer, the barrier height between the silicon/PEDOT:PSS interface can be effectively enhanced. Meanwhile, the carrier recombination at the interface is significantly reduced. These results can contribute to better understanding of the interfacial mechanism of silicon/PEDOT:PSS interface, and further improving the device performance of silicon/organic solar cells.

Improved Work Function of Poly(3,4-ethylenedioxythiophene): Poly(styrenesulfonic acid) and its Effect on Hybrid Silicon/Organic Heterojunction Solar Cells

NASA Astrophysics Data System (ADS)

Shen, Xiaojuan; Chen, Ling; Pan, Jianmei; Hu, Yue; Li, Songjun; Zhao, Jie

2016-11-01

Hybrid silicon/organic solar cells have been recently extensively investigated due to their simple structure and low-cost fabrication process. However, the efficiency of the solar cells is greatly limited by the barrier height as well as the carrier recombination at the silicon/organic interface. In this work, hydrochloroplatinic acid (H2PtCl6) is employed into the poly(3,4-ethlenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) solution, and the work function (WF) of the PEDOT:PSS layer has been successfully improved. Based on the Pt-modified PEDOT:PSS layer, the efficiency of the silicon/PEDOT:PSS cell can be increased to 11.46%, corresponding to 20% enhancement to the one without platinum (Pt) modification. Theoretical and experimental results show that, when increasing the WF of the PEDO:PSS layer, the barrier height between the silicon/PEDOT:PSS interface can be effectively enhanced. Meanwhile, the carrier recombination at the interface is significantly reduced. These results can contribute to better understanding of the interfacial mechanism of silicon/PEDOT:PSS interface, and further improving the device performance of silicon/organic solar cells.

Petascale Computing for Ground-Based Solar Physics with the DKIST Data Center

NASA Astrophysics Data System (ADS)

Berukoff, Steven J.; Hays, Tony; Reardon, Kevin P.; Spiess, DJ; Watson, Fraser; Wiant, Scott

2016-05-01

When construction is complete in 2019, the Daniel K. Inouye Solar Telescope will be the most-capable large aperture, high-resolution, multi-instrument solar physics facility in the world. The telescope is designed as a four-meter off-axis Gregorian, with a rotating Coude laboratory designed to simultaneously house and support five first-light imaging and spectropolarimetric instruments. At current design, the facility and its instruments will generate data volumes of 3 PB per year, and produce 107-109 metadata elements.The DKIST Data Center is being designed to store, curate, and process this flood of information, while providing association of science data and metadata to its acquisition and processing provenance. The Data Center will produce quality-controlled calibrated data sets, and make them available freely and openly through modern search interfaces and APIs. Documented software and algorithms will also be made available through community repositories like Github for further collaboration and improvement.We discuss the current design and approach of the DKIST Data Center, describing the development cycle, early technology analysis and prototyping, and the roadmap ahead. We discuss our iterative development approach, the underappreciated challenges of calibrating ground-based solar data, the crucial integration of the Data Center within the larger Operations lifecycle, and how software and hardware support, intelligently deployed, will enable high-caliber solar physics research and community growth for the DKIST's 40-year lifespan.

In Defense of Defining Science Education as the Science/Society Interface.

ERIC Educational Resources Information Center

Yager, Robert E.

1985-01-01

Defends the definition of science education as the interface of science and society, pointing out the fallacies of an alternative definition promulgated by Good, Herron, Lawson, and Renner who, in a previous article (SE 537 615) examined and rejected the science/society interface definition in favor of their own definition. (DH)

Working With Solar System Ambassadors

NASA Astrophysics Data System (ADS)

Ferrari, K.

2001-11-01

The Solar System Ambassadors Program is a public outreach program designed to work with motivated volunteers across the nation. These competitively selected volunteers organize and conduct public events that communicate exciting discoveries and plans in Solar System research, exploration and technology through non-traditional forums; e.g. community service clubs, libraries, museums, planetariums, "star parties," mall displays, etc. Each Ambassador participates in on-line (web-based) training sessions that provide interaction with NASA scientists, engineers and project team members. As such, each Ambassador's experience with the space program becomes personalized. Training sessions provide Ambassadors with general background on each mission and educate them concerning specific mission milestones, such as launches, planetary flybys, first image returns, arrivals, and ongoing key discoveries. Additionally, projects provide limited supplies of videos, slide sets, booklets, pamphlets, posters, postcards, lithographs, on-line materials, resource links and information. In addition to participating in on-line trainings with Ambassadors, scientists will be given the opportunity to interact with, and mentor volunteer Ambassadors at regional, weekend conferences designed to strengthen the Ambassadors' knowledge of space science and exploration, thereby improving the space science message that goes out to the general public through these enthusiastic volunteers. Integrating volunteers across the country in a public-engagement program helps optimize project funding set aside for education and outreach purposes, establishing a nationwide network of regional contacts. At the same time, members of communities across the country become an extended part of each mission's team and an important interface between the space exploration community and the general public at large.

Interface Engineering of Organic Schottky Barrier Solar Cells and Its Application in Enhancing Performances of Planar Heterojunction Solar Cells

PubMed Central

Jin, Fangming; Su, Zisheng; Chu, Bei; Cheng, Pengfei; Wang, Junbo; Zhao, Haifeng; Gao, Yuan; Yan, Xingwu; Li, Wenlian

2016-01-01

In this work, we describe the performance of organic Schottky barrier solar cells with the structure of ITO/molybdenum oxide (MoOx)/boron subphthalocyanine chloride (SubPc)/bathophenanthroline (BPhen)/Al. The SubPc-based Schottky barrier solar cells exhibited a short-circuit current density (Jsc) of 2.59 mA/cm2, an open-circuit voltage (Voc) of 1.06 V, and a power conversion efficiency (PCE) of 0.82% under simulated AM1.5 G solar illumination at 100 mW/cm2. Device performance was substantially enhanced by simply inserting thin organic hole transport material into the interface of MoOx and SubPc. The optimized devices realized a 180% increase in PCE of 2.30% and a peak Voc as high as 1.45 V was observed. We found that the improvement is due to the exciton and electron blocking effect of the interlayer and its thickness plays a vital role in balancing charge separation and suppressing quenching effect. Moreover, applying such interface engineering into MoOx/SubPc/C60 based planar heterojunction cells substantially enhanced the PCE of the device by 44%, from 3.48% to 5.03%. Finally, we also investigated the requirements of the interface material for Schottky barrier modification. PMID:27185635

Interface engineering of high-Mg-content MgZnO/BeO/Si for p-n heterojunction solar-blind ultraviolet photodetectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang, H. L.; Mei, Z. X.; Zhang, Q. H.

2011-05-30

High-quality wurtzite MgZnO film was deposited on Si(111) substrate via a delicate interface engineering using BeO, by which solar-blind ultraviolet photodetectors were fabricated on the n-MgZnO(0001)/p-Si(111) heterojunction. A thin Be layer was deposited on clean Si surface with subsequent in situ oxidation processes, which provides an excellent template for high-Mg-content MgZnO growth. The interface controlling significantly improves the device performance, as the photodetector demonstrates a sharp cutoff wavelength at 280 nm, consistent with the optical band gap of the epilayer. Our experimental results promise potential applications of this technique in integration of solar-blind ultraviolet optoelectronic device with Si microelectronic technologies.

Developments toward an 18% efficient silicon solar cell

NASA Technical Reports Server (NTRS)

Meulenberg, A., Jr.

1983-01-01

Limitations to increased open-circuit voltage were identified and experimentally verified for 0.1 ohm-cm solar cells with heavily doped emitters. After major reduction in the dark current contribution from the metal-silicon interface of the grid contacts, the surface recombination velocity of the oxide-silicon interface of shallow junction solar cells is the limiting factor. In deep junction solar cells, where the junction field does not aid surface collection, the emitter bulk is the limiting factor. Singly-diffused, shallow junction cells have been fabricated with open circuit voltages in excess of 645 mV. Double-diffusion shallow and deep junctions cells have displayed voltages above 650 mV. MIS solar cells formed on 0.1 ohm-cm substrates have exibited the lowest dark currents produced in the course of the contract work.

Resource Materials for Nanoscale Science and Technology Education

NASA Astrophysics Data System (ADS)

Lisensky, George

2006-12-01

Nanotechnology and advanced materials examples can be used to explore science and engineering concepts, exhibiting the "wow" and potential of nanotechnology, introducing prospective scientists to key ideas, and educating a citizenry capable of making well-informed technology-driven decisions. For example, material syntheses an atomic layer at a time have already revolutionized lighting and display technologies and dramatically expanded hard drive storage capacities. Resource materials include kits, models, and demonstrations that explain scanning probe microscopy, x-ray diffraction, information storage, energy and light, carbon nanotubes, and solid-state structures. An online Video Lab Manual, where movies show each step of the experiment, illustrates more than a dozen laboratory experiments involving nanoscale science and technology. Examples that are useful at a variety of levels when instructors provide the context include preparation of self-assembled monolayers, liquid crystals, colloidal gold, ferrofluid nanoparticles, nickel nanowires, solar cells, electrochromic thin films, organic light emitting diodes, and quantum dots. These resources have been developed, refined and class tested at institutions working with the Materials Research Science and Engineering Center on Nanostructured Interfaces at the University of Wisconsin-Madison (http://mrsec.wisc.edu/nano).

Solar Week 2000: Using role models to encourage an interest in science

NASA Astrophysics Data System (ADS)

Alexander, D.

2000-12-01

Solar Week 2000 is a week-long set of games and activities allowing students to interact directly with solar science and solar scientists. The main goal of Solar Week was to provide young women, primarily in grades 6-8, with access to role models in the sciences. The scientists participating in Solar Week are women from a variety of backgrounds and with a variety of scientific expertise. An online bulletin board was used to foster discussion between the students and the scientists about both science and career issues. In this presentation I will discuss the successes and failures of the first run of Solar Week which occurred on 9-13 October 2000. Our aim is to provide some insight into doing activity-based space science on the web and to discuss the lessons-learned from tailoring to a specific group of participants.

The Glory Program: Global Science from a Unique Spacecraft Integration

NASA Technical Reports Server (NTRS)

Bajpayee Jaya; Durham, Darcie; Ichkawich, Thomas

2006-01-01

The Glory program is an Earth and Solar science mission designed to broaden science community knowledge of the environment. The causes and effects of global warming have become a concern in recent years and Glory aims to contribute to the knowledge base of the science community. Glory is designed for two functions: one is solar viewing to monitor the total solar irradiance and the other is observing the Earth s atmosphere for aerosol composition. The former is done with an active cavity radiometer, while the latter is accomplished with an aerosol polarimeter sensor to discern atmospheric particles. The Glory program is managed by NASA Goddard Space Flight Center (GSFC) with Orbital Sciences in Dulles, VA as the prime contractor for the spacecraft bus, mission operations, and ground system. This paper will describe some of the more unique features of the Glory program including the integration and testing of the satellite and instruments as well as the science data processing. The spacecraft integration and test approach requires extensive analysis and additional planning to ensure existing components are successfully functioning with the new Glory components. The science mission data analysis requires development of mission unique processing systems and algorithms. Science data analysis and distribution will utilize our national assets at the Goddard Institute for Space Studies (GISS) and the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP). The Satellite was originally designed and built for the Vegetation Canopy Lidar (VCL) mission, which was terminated in the middle of integration and testing due to payload development issues. The bus was then placed in secure storage in 2001 and removed from an environmentally controlled container in late 2003 to be refurbished to meet the Glory program requirements. Functional testing of all the components was done as a system at the start of the program, very different from a traditional program. The plan for Glory is to minimize any changes to the spacecraft in order to meet the Glory requirements. This means that the instrument designs must adhere to the existing interfaces and capabilities as much as possible. Given Glory's unique history and the potential science return, the program is one of significant value to both the science community and the world. The findings Glory promises will improve our understanding of the drivers for global climate change for a minimal investment. The program hopes to show that reuse of existing government assets can result in a lower cost, and fully successful mission.

Design of Instrument Control Software for Solar Vector Magnetograph at Udaipur Solar Observatory

NASA Astrophysics Data System (ADS)

Gosain, Sanjay; Venkatakrishnan, P.; Venugopalan, K.

2004-04-01

A magnetograph is an instrument which makes measurement of solar magnetic field by measuring Zeeman induced polarization in solar spectral lines. In a typical filter based magnetograph there are three main modules namely, polarimeter, narrow-band spectrometer (filter), and imager(CCD camera). For a successful operation of magnetograph it is essential that these modules work in synchronization with each other. Here, we describe the design of instrument control system implemented for the Solar Vector Magnetograph under development at Udaipur Solar Observatory. The control software is written in Visual Basic and exploits the Component Object Model (COM) components for a fast and flexible application development. The user can interact with the instrument modules through a Graphical User Interface (GUI) and can program the sequence of magnetograph operations. The integration of Interactive Data Language (IDL) ActiveX components in the interface provides a powerful tool for online visualization, analysis and processing of images.

Interfacial micropore defect formation in PEDOT:PSS-Si hybrid solar cells probed by TOF-SIMS 3D chemical imaging.

PubMed

Thomas, Joseph P; Zhao, Liyan; Abd-Ellah, Marwa; Heinig, Nina F; Leung, K T

2013-07-16

Conducting p-type polymer layers on n-type Si have been widely studied for the fabrication of cost-effective hybrid solar cells. In this work, time-of-flight secondary ion mass spectrometry (TOF-SIMS) is used to provide three-dimensional chemical imaging of the interface between poly(3,4-ethylene-dioxythiophene):polystyrenesulfonate (PEDOT:PSS) and SiOx/Si in a hybrid solar cell. To minimize structural damage to the polymer layer, an Ar cluster sputtering source is used for depth profiling. The present result shows the formation of micropore defects in the interface region of the PEDOT:PSS layer on the SiOx/Si substrate. This interfacial micropore defect formation becomes more prominent with increasing thickness of the native oxide layer, which is a key device parameter that greatly affects the hybrid solar cell performance. Three-dimensional chemical imaging coupled with Ar cluster ion sputtering has therefore been demonstrated as an emerging technique for probing the interface of this and other polymer-inorganic systems.

Review of grain interior, grain boundary, and interface effects of K in CIGS solar cells: Mechanisms for performance enhancement

DOE PAGES

Muzzillo, Christopher P.

2017-07-16

Introducing K into Cu(In,Ga)(Se,S) 2 (CIGS) absorbers has led to recent world record power conversion efficiencies for thin film polycrystalline solar cells. In this work, the diverse phenomena associated with K in CIGS were reviewed, and overarching mechanisms were identified. The effects of K depend on its distribution among grain interiors (GIs), grain boundaries (GBs), and interfaces. High substrate Na and low temperature favor GI K incorporation, while low Na and high temperature favor segregation of K at GBs. Depositing KInSe 2 (or KIn 1-yGaySe 2) by co-evaporation or KF post-deposition treatment onto CIGS reduces buffer interface recombination in themore » final solar cells. KInSe 2 decomposes in air, which makes characterization difficult and may affect performance. In conclusion, the mechanism for reduced interface recombination could be direct passivation, beneficial compound precursor, oxidation barrier, or favorable diffusion alteration.« less

Review of grain interior, grain boundary, and interface effects of K in CIGS solar cells: Mechanisms for performance enhancement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muzzillo, Christopher P.

Introducing K into Cu(In,Ga)(Se,S) 2 (CIGS) absorbers has led to recent world record power conversion efficiencies for thin film polycrystalline solar cells. In this work, the diverse phenomena associated with K in CIGS were reviewed, and overarching mechanisms were identified. The effects of K depend on its distribution among grain interiors (GIs), grain boundaries (GBs), and interfaces. High substrate Na and low temperature favor GI K incorporation, while low Na and high temperature favor segregation of K at GBs. Depositing KInSe 2 (or KIn 1-yGaySe 2) by co-evaporation or KF post-deposition treatment onto CIGS reduces buffer interface recombination in themore » final solar cells. KInSe 2 decomposes in air, which makes characterization difficult and may affect performance. In conclusion, the mechanism for reduced interface recombination could be direct passivation, beneficial compound precursor, oxidation barrier, or favorable diffusion alteration.« less

Floating rGO-based black membranes for solar driven sterilization.

PubMed

Zhang, Yao; Zhao, Dengwu; Yu, Fan; Yang, Chao; Lou, Jinwei; Liu, Yanming; Chen, Yingying; Wang, Zhongyong; Tao, Peng; Shang, Wen; Wu, Jianbo; Song, Chengyi; Deng, Tao

2017-12-14

This paper presents a new steam sterilization approach that uses a solar-driven evaporation system at the water/air interface. Compared to the conventional solar autoclave, this new steam sterilization approach via interfacial evaporation requires no complex system design to bear high steam pressure. In such a system, a reduced graphene oxide/polytetrafluoroethylene composite membrane floating at the water/air interface serves as a light-to-heat conversion medium to harvest and convert incident solar light into localized heat. Such localized heat raises the temperature of the membrane substantially and helps generate steam with a temperature higher than 120 °C. A sterilization device that takes advantage of the interfacial solar-driven evaporation system was built and its successful sterilization capability was demonstrated through both chemical and biological sterilization tests. The interfacial evaporation-based solar driven sterilization approach offers a potential low cost solution to meet the need for sterilization in undeveloped areas that lack electrical power but have ample solar radiation.

Community Coordinated Modeling Center Support of Science Needs for Integrated Data Environment

NASA Technical Reports Server (NTRS)

Kuznetsova, M. M.; Hesse, M.; Rastatter, L.; Maddox, M.

2007-01-01

Space science models are essential component of integrated data environment. Space science models are indispensable tools to facilitate effective use of wide variety of distributed scientific sources and to place multi-point local measurements into global context. The Community Coordinated Modeling Center (CCMC) hosts a set of state-of-the- art space science models ranging from the solar atmosphere to the Earth's upper atmosphere. The majority of models residing at CCMC are comprehensive computationally intensive physics-based models. To allow the models to be driven by data relevant to particular events, the CCMC developed an online data file generation tool that automatically downloads data from data providers and transforms them to required format. CCMC provides a tailored web-based visualization interface for the model output, as well as the capability to download simulations output in portable standard format with comprehensive metadata and user-friendly model output analysis library of routines that can be called from any C supporting language. CCMC is developing data interpolation tools that enable to present model output in the same format as observations. CCMC invite community comments and suggestions to better address science needs for the integrated data environment.

Emitter/absorber interface of CdTe solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Tao; Kanevce, Ana; Sites, James R.

The performance of CdTe solar cells can be very sensitive to their emitter/absorber interfaces, especially for high-efficiency cells with improved bulk properties. When interface defect states are located at efficient recombination energies, performance losses from acceptor-type interface defects can be significant. Numerical simulations show that the emitter/absorber band alignment, the emitter doping and thickness, and the defect properties of the interface (i.e. defect density, defect type, and defect energy) can all play significant roles in the interface recombination. In particular, a type I heterojunction with small conduction-band offset (0.1 eV /= 0.4 eV), however, can impede electron transport and leadmore » to a reduction of photocurrent and fill-factor. In contrast to the spike, a 'cliff' (.delta..EC < 0 eV) is likely to allow many holes in the vicinity of the interface, which will assist interface recombination and result in a reduced open-circuit voltage. In addition, a thin and highly-doped emitter can invert the absorber, form a large hole barrier, and decrease device performance losses due to high interface defect density. CdS is the most common emitter material used in CdTe solar cells, but the CdS/CdTe interface is in the cliff category and is not favorable from the band-offset perspective. Other n-type emitter choices, such as (Mg,Zn)O, Cd(S,O), or (Cd,Mg)Te, can be tuned by varying the elemental ratio for an optimal positive value of ..delta..EC. These materials are predicted to yield higher voltages and would therefore be better candidates for the CdTe-cell emitter.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Chen; Paudel, Naba R.; Yan, Yanfa

Atom probe tomography (APT) data acquired from a CAMECA LEAP 4000 XHR for the CdS/CdTe interface for a non-CdCl 2 treated CdTe solar cell as well as the mass spectrum of an APT data set including a GB in a CdCl 2-treated CdTe solar cell are presented. Scanning electron microscopy (SEM) data showing the evolution of sample preparation for APT and scanning transmission electron microscopy (STEM) electron beam induced current (EBIC) are also presented. As a result, these data show mass spectrometry peak decomposition of Cu and Te within an APT dataset, the CdS/CdTe interface of an untreated CdTe solarmore » cell, preparation of APT needles from the CdS/CdTe interface in superstrate grown CdTe solar cells, and the preparation of a cross-sectional STEM EBIC sample.« less

The Interface Between Chemical and Oxide Materials in the DSPEC

NASA Astrophysics Data System (ADS)

Meyer, Thomas; Alibabaei, Leila; Sherman, Benjamin; Sheridan, Matthew; Ashford, Dennis; Lapides, Alex; Brennaman, Kyle; Nayak, Animesh; Roy, Subhangi

Significant challenges exist for both chemical and oxide materials in the Dye Sensitized Photoelectrosynthesis Cell (DSPEC) for water oxidation or CO2 reduction. They arise from light absorption, the energetics of electron or hole injection, the accumulation of multiple redox equivalents at catalysts for water oxidation or water/CO2 reduction in competition with back electron transfer, and sustained, long term performance. These challenges are being met by the use of a variety of chromophores (metal complexes, organic dyes, porphyrins), broad application of nanoparticle mesoscopic oxide films, atomic layer deposition (ALD) to prepare core/shell and stabilizing overlayer structures, and recent advances in the molecular catalysis of water oxidation and CO2 reduction. UNC EFRC Center for Solar Fuels, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001011.

KSC-2013-2628

NASA Image and Video Library

2013-06-10

VANDENBERG AFB – Orbital Sciences engineers connect the payload fairing over NASA's IRIS spacecraft. The fairing connects to the nose of the Orbital Sciences Pegasus XL rocket that will lift the solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch on a Pegasus XL rocket. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Tony Vauclin

KSC-2013-2642

NASA Image and Video Library

2013-06-10

VANDENBERG AFB – Orbital Sciences team engineers monitor the connection of the payload fairing over NASA's IRIS spacecraft. The fairing connects to the nose of the Orbital Sciences Pegasus XL rocket that will lift the solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch on a Pegasus XL rocket. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Tony Vauclin

KSC-2013-2618

NASA Image and Video Library

2013-06-10

VANDENBERG AFB – Orbital Sciences team members watch as engineers connect the payload fairing over NASA's IRIS spacecraft. The fairing connects to the nose of the Orbital Sciences Pegasus XL rocket that will lift the solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch on a Pegasus XL rocket. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Tony Vauclin

KSC-2013-2617

NASA Image and Video Library

2013-06-10

VANDENBERG AFB - Orbital Sciences engineers connect the payload fairing over NASA's IRIS spacecraft. The fairing connects to the nose of the Orbital Sciences Pegasus XL rocket that will lift the solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch on a Pegasus XL rocket. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Tony Vauclin

KSC-2013-2636

NASA Image and Video Library

2013-06-10

VANDENBERG AFB – Orbital Sciences engineers connect the payload fairing over NASA's IRIS spacecraft. The fairing connects to the nose of the Orbital Sciences Pegasus XL rocket that will lift the solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch on a Pegasus XL rocket. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Tony Vauclin

KSC-2013-2641

NASA Image and Video Library

2013-06-10

VANDENBERG AFB – Orbital Sciences engineers monitor the connection of the payload fairing over NASA's IRIS spacecraft. The fairing connects to the nose of the Orbital Sciences Pegasus XL rocket that will lift the solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch on a Pegasus XL rocket. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Tony Vauclin

KSC-2013-2635

NASA Image and Video Library

2013-06-10

VANDENBERG AFB – Orbital Sciences engineers connect the payload fairing over NASA's IRIS spacecraft. The fairing connects to the nose of the Orbital Sciences Pegasus XL rocket that will lift the solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch on a Pegasus XL rocket. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Tony Vauclin

KSC-2013-2633

NASA Image and Video Library

2013-06-10

VANDENBERG AFB – Orbital Sciences team members move the second half of the payload fairing before it is placed over NASA's IRIS spacecraft. The fairing connects to the nose of the Orbital Sciences Pegasus XL rocket that will lift the solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch on a Pegasus XL rocket. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Tony Vauclin

KSC-2013-2639

NASA Image and Video Library

2013-06-10

VANDENBERG AFB – Orbital Sciences engineers connect the payload fairing over NASA's IRIS spacecraft. The fairing connects to the nose of the Orbital Sciences Pegasus XL rocket that will lift the solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch on a Pegasus XL rocket. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Tony Vauclin

KSC-2013-2637

NASA Image and Video Library

2013-06-10

VANDENBERG AFB – Orbital Sciences engineers connect the payload fairing over NASA's IRIS spacecraft. The fairing connects to the nose of the Orbital Sciences Pegasus XL rocket that will lift the solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch on a Pegasus XL rocket. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Tony Vauclin

KSC-2013-2630

NASA Image and Video Library

2013-06-10

VANDENBERG AFB – Orbital Sciences team members move the second half of the payload fairing before it is placed over NASA's IRIS spacecraft. The fairing connects to the nose of the Orbital Sciences Pegasus XL rocket that will lift the solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch on a Pegasus XL rocket. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Tony Vauclin

KSC-2013-2626

NASA Image and Video Library

2013-06-10

VANDENBERG AFB – Orbital Sciences team members move the second half of the payload fairing before it is placed over NASA's IRIS spacecraft. The fairing connects to the nose of the Orbital Sciences Pegasus XL rocket that will lift the solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch on a Pegasus XL rocket. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Tony Vauclin

KSC-2013-2616

NASA Image and Video Library

2013-06-11

Orbital Sciences engineers connect the payload fairing over NASA's IRIS spacecraft. The fairing connects to the nose of the Orbital Sciences Pegasus XL rocket that will lift the solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch on a Pegasus XL rocket. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Tony Vauclin

KSC-2013-2629

NASA Image and Video Library

2013-06-10

VANDENBERG AFB – Orbital Sciences team members move the second half of the payload fairing before it is placed over NASA's IRIS spacecraft. The fairing connects to the nose of the Orbital Sciences Pegasus XL rocket that will lift the solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch on a Pegasus XL rocket. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Tony Vauclin

Operation strategy for grid-tied DC-coupling power converter interface integrating wind/solar/battery

NASA Astrophysics Data System (ADS)

Jou, H. L.; Wu, J. C.; Lin, J. H.; Su, W. N.; Wu, T. S.; Lin, Y. T.

2017-11-01

The operation strategy for a small-capacity grid-tied DC-coupling power converter interface (GDPCI) integrating wind energy, solar energy and battery energy storage is proposed. The GDPCI is composed of a wind generator, a solar module set a battery bank, a boost DC-DC power converter (DDPC), a bidirectional DDPC power converter, an AC-DC power converter (ADPC) and a five-level DC-AC inverter (DAI). A solar module set, a wind generator and a battery bank are coupled to the common DC bus through the boost DDPC, the ADPC and the bidirectional DDPC, respectively. For verifying the performance of the GDPCI under different operation modes, computer simulation is carried out by PSIM.

The Virtual Solar Observatory and the Heliophysics Meta-Virtual Observatory

NASA Technical Reports Server (NTRS)

Gurman, Joseph B.

2007-01-01

The Virtual Solar Observatory (VSO) is now able to search for solar data ranging from the radio to gamma rays, obtained from space and groundbased observatories, from 26 sources at 12 data providers, and from 1915 to the present. The solar physics community can use a Web interface or an Application Programming Interface (API) that allows integrating VSO searches into other software, including other Web services. Over the next few years, this integration will be especially obvious as the NASA Heliophysics division sponsors the development of a heliophysics-wide virtual observatory (VO), based on existing VO's in heliospheric, magnetospheric, and ionospheric physics as well as the VSO. We examine some of the challenges and potential of such a "meta-VO."

The role of the CeO 2 /BiVO 4 interface in optimized Fe–Ce oxide coatings for solar fuels photoanodes

DOE PAGES

Shinde, A.; Li, G.; Zhou, L.; ...

2016-09-09

Solar fuel generators entail a high degree of materials integration, and efficient photoelectrocatalysis of the constituent reactions hinges upon the establishment of highly functional interfaces. Our recent application of high throughput experimentation to interface discovery for solar fuels photoanodes has revealed several surprising and promising mixed-metal oxide coatings for BiVO 4. Furthermore, when using sputter deposition of composition and thickness gradients on a uniform BiVO 4 film, we systematically explore photoanodic performance as a function of the composition and loading of Fe–Ce oxide coatings. This combinatorial materials integration study not only enhances the performance of this new class of materialsmore » but also identifies CeO 2 as a critical ingredient that merits detailed study. A heteroepitaxial CeO 2(001)/BiVO4(010) interface is identified in which Bi and V remain fully coordinated to O such that no surface states are formed. Ab initio calculations of the integrated materials and inspection of the electronic structure reveals mechanisms by which CeO 2 facilitates charge transport while mitigating deleterious recombination. Our results support the observations that addition of Ce to BiVO 4 coatings greatly enhances photoelectrocatalytic activity, providing an important strategy for developing a scalable solar fuels technology.« less

Quantum Dot Sensitized Solar Cells Based on Ternary Metal Oxide Nanowires

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Wenyong; Tang, Jinke; Dahnovsky, Yuri

In Phase I of this project we investigate quantum dot sensitized solar cells (QDSSCs) based on ternary metal oxide nanowires and study the physical and chemical mechanisms that govern device operation. Our research has the following five objectives: (1) synthesis of ternary metal oxide nanowires, (2) synthesis of QDs and exploration of non-solution based QD deposition methods, (3) physical and electro-optical characterizations of fabricated solar devices, (4) device modeling and first-principle theoretical study of transport physics, and (5) investigation of long-term stability issues of QD sensitized solar cells. In Phase II of this project our first major research goal ismore » to investigate magnetically doped quantum dots and related spin polarization effect, which could improve light absorption and suppress electron relaxation in the QDs. We will utilize both physical and chemical methods to synthesize these doped QDs. We will also study magnetically modified nanowires and introduce spin-polarized transport into QDSSCs, and inspect its impact on forward electron injection and back electron transfer processes. Our second goal is to study novel solid-state electrolytes for QDSSCs. Specifically, we will inspect a new type of polymer electrolytes based on a modified polysulfide redox couple, and examine the effect of their electrical properties on QDSSC performance. These solid-state electrolytes could also be used as filler materials for in situ sample fracturing in STM and enable cross-sectional interface examination of QD/nanowire structures. Our third research goal is to examine the interfacial properties such as energy level alignment at QD/nanowire interfaces using the newly developed Cross-sectional Scanning Tunneling Microscopy and Spectroscopy technique for non-cleavable materials. This technique allows a direct probing of band structures and alignment at device interfaces, which could generate important insight into the mechanisms that govern QDSSC operation. These investigations will be carried out through a close collaboration between our experimental and theoretical efforts in this project. This project initiates an important research direction in the jurisdiction of Wyoming. It brings together researchers from different academic disciplines including physics, chemistry, materials science, and engineering to work on one common scientific theme, and is a vital step towards the establishment of an nationally competitive research program in energy-related nanomaterials in the state of Wyoming.« less

Interfacial engineering of printable bottom back metal electrodes for full-solution processed flexible organic solar cells

NASA Astrophysics Data System (ADS)

Zhen, Hongyu; Li, Kan; Zhang, Yaokang; Chen, Lina; Niu, Liyong; Wei, Xiaoling; Fang, Xu; You, Peng; Liu, Zhike; Wang, Dongrui; Yan, Feng; Zheng, Zijian

2018-01-01

Printing of metal bottom back electrodes of flexible organic solar cells (FOSCs) at low temperature is of great significance to realize the full-solution fabrication technology. However, this has been difficult to achieve because often the interfacial properties of those printed electrodes, including conductivity, roughness, work function, optical and mechanical flexibility, cannot meet the device requirement at the same time. In this work, we fabricate printed Ag and Cu bottom back cathodes by a low-temperature solution technique named polymer-assisted metal deposition (PAMD) on flexible PET substrates. Branched polyethylenimine (PEI) and ZnO thin films are used as the interface modification layers (IMLs) of these cathodes. Detailed experimental studies on the electrical, mechanical, and morphological properties, and simulation study on the optical properties of these IMLs are carried out to understand and optimize the interface of printed cathodes. We demonstrate that the highest power conversion efficiency over 3.0% can be achieved from a full-solution processed OFSC with the device structure being PAMD-Ag/PEI/P3HT:PC61BM/PH1000. This device also acquires remarkable stability upon repeating bending tests. Project supported by the Research Grant Council of Hong Kong (No. PolyUC5015-15G), the Hong Kong Polytechnic University (No. G-SB06), and the National Natural Science Foundation of China (Nos. 21125316, 21434009, 51573026).

Enabling Interoperability in Heliophysical Domains

NASA Astrophysics Data System (ADS)

Bentley, Robert

2013-04-01

There are many aspects of science in the Solar System that are overlapping - phenomena observed in one domain can have effects in other domains. However, there are many problems related to exploiting the data in cross-disciplinary studies because of lack of interoperability of the data and services. The CASSIS project is a Coordination Action funded under FP7 that has the objective of improving the interoperability of data and services related Solar System science. CASSIS has been investigating how the data could be made more accessible with some relatively minor changes to the observational metadata. The project has been looking at the services that are used within the domain and determining whether they are interoperable with each other and if not what would be required make them so. It has also been examining all types of metadata that are used when identifying and using observations and trying to make them more compliant with techniques and standards developed by bodies such as the International Virtual Observatory Alliance (IVOA). Many of the lessons that are being learnt in the study are applicable to domains that go beyond those directly involved in heliophysics. Adopting some simple standards related to the design of the services interfaces and metadata that are used would make it much easier to investigate interdisciplinary science topics. We will report on our finding and describe a roadmap for the future. For more information about CASSIS, please visit the project Web site on cassis-vo.eu

The Global Coronal Structure Investigation

NASA Technical Reports Server (NTRS)

Golub, Leon

1998-01-01

During the past year we have completed the changeover from the NIXT program to the new TXI sounding rocket program. The NIXT effort, aimed at evaluating the viability of the remaining portions of the NIXT hardware and design, has been finished and the portions of the NIXT which are viable and flightworthy, such as filters, mirror mounting hardware, electronics and telemetry interface systems, are now part of the new rocket payload. The backup NIXT multilayer-coated x-ray telescope and its mounting hardware have been completely fabricated and are being stored for possible future use in the TXI rocket. The H-alpha camera design is being utilized in the TXI program for real-time pointing verification and control via telemetry. A new H-alpha camera has been built, with a high-resolution RS170 CCD camera output. Two papers, summarizing scientific results from the NIXT rocket program, have been written and published this year: 1. "The Solar X-ray Corona," by L. Golub, Astrophysics and Space Science, 237, 33 (1996). 2. "Difficulties in Observing Coronal Structure," Keynote Paper, Proceedings STEPWG1 Workshop on Measurements and Analyses of the Solar 3D Magnetic Field, Solar Physics, 174, 99 (1997).

Recombination in Perovskite Solar Cells: Significance of Grain Boundaries, Interface Traps, and Defect Ions.

PubMed

Sherkar, Tejas S; Momblona, Cristina; Gil-Escrig, Lidón; Ávila, Jorge; Sessolo, Michele; Bolink, Henk J; Koster, L Jan Anton

2017-05-12

Trap-assisted recombination, despite being lower as compared with traditional inorganic solar cells, is still the dominant recombination mechanism in perovskite solar cells (PSCs) and limits their efficiency. We investigate the attributes of the primary trap-assisted recombination channels (grain boundaries and interfaces) and their correlation to defect ions in PSCs. We achieve this by using a validated device model to fit the simulations to the experimental data of efficient vacuum-deposited p-i-n and n-i-p CH 3 NH 3 PbI 3 solar cells, including the light intensity dependence of the open-circuit voltage and fill factor. We find that, despite the presence of traps at interfaces and grain boundaries (GBs), their neutral (when filled with photogenerated charges) disposition along with the long-lived nature of holes leads to the high performance of PSCs. The sign of the traps (when filled) is of little importance in efficient solar cells with compact morphologies (fused GBs, low trap density). On the other hand, solar cells with noncompact morphologies (open GBs, high trap density) are sensitive to the sign of the traps and hence to the cell preparation methods. Even in the presence of traps at GBs, trap-assisted recombination at interfaces (between the transport layers and the perovskite) is the dominant loss mechanism. We find a direct correlation between the density of traps, the density of mobile ionic defects, and the degree of hysteresis observed in the current-voltage ( J - V ) characteristics. The presence of defect states or mobile ions not only limits the device performance but also plays a role in the J - V hysteresis.

Achieving High Performance Perovskite Solar Cells

NASA Astrophysics Data System (ADS)

Yang, Yang

2015-03-01

Recently, metal halide perovskite based solar cell with the characteristics of rather low raw materials cost, great potential for simple process and scalable production, and extreme high power conversion efficiency (PCE), have been highlighted as one of the most competitive technologies for next generation thin film photovoltaic (PV). In UCLA, we have realized an efficient pathway to achieve high performance pervoskite solar cells, where the findings are beneficial to this unique materials/devices system. Our recent progress lies in perovskite film formation, defect passivation, transport materials design, interface engineering with respect to high performance solar cell, as well as the exploration of its applications beyond photovoltaics. These achievements include: 1) development of vapor assisted solution process (VASP) and moisture assisted solution process, which produces perovskite film with improved conformity, high crystallinity, reduced recombination rate, and the resulting high performance; 2) examination of the defects property of perovskite materials, and demonstration of a self-induced passivation approach to reduce carrier recombination; 3) interface engineering based on design of the carrier transport materials and the electrodes, in combination with high quality perovskite film, which delivers 15 ~ 20% PCEs; 4) a novel integration of bulk heterojunction to perovskite solar cell to achieve better light harvest; 5) fabrication of inverted solar cell device with high efficiency and flexibility and 6) exploration the application of perovskite materials to photodetector. Further development in film, device architecture, and interfaces will lead to continuous improved perovskite solar cells and other organic-inorganic hybrid optoelectronics.

Solar-B X-ray Telescope (XRT) Concept Study Report

NASA Astrophysics Data System (ADS)

Golub, Leon

1999-10-01

The X-ray observations from the Yohkoh SXT provided the greatest step forward in our understanding of the solar corona in nearly two decades. Expanding on the accomplishments of Yohkoh, we believe that the scientific objectives of the Solar-B mission are achieved with a significantly improved X-ray telescope (XRT) similar to the SXT. The Solar-B XRT will have twice the spatial resolution and a broader temperature response, while building on the knowledge gained from the successful Yohkoh mission. We present the scientific justification for this view, discuss the instrumental requirements that flow from the scientific objectives, and describe the instrumentation to meet these requirements. We then provide a detailed discussion of the design activities carried out during Phase A, noting the conclusions that were reached in terms of their implications for the detailed design activities which are now commencing. Details of the instrument that have changed as a result of the Phase A studied are specifically noted, and areas of concern going into Phase B are highlighted. XRT is a grazing-incidence (GI) modified Wolter I X-ray telescope, of 35cm inner diameter and 2.7m focal length. The 2048x2048 back-illuminated CCD (now an ISAS responsibility) has 13.5 micron pixels, corresponding to 1.0 arcsec and giving full Sun field of view. This will be the highest resolution GI X-ray telescope ever flown for Solar coronal studies, and it has been designed specifically to observe both the high and low temperature coronal plasma. A small optical telescope provides visible light images for co-alignment with the Solar-B optical and EUV instruments. The XRT science team is working in close cooperation with our Japanese colleagues in the design and construction of this instrument. All of the expertise and resources of the High Energy and Solar/Stellar Divisions of the Center for Astrophysics are being made available to this program, and our team will carry its full share of responsibility for mission operations, data reduction and education and public outreach. All aspects of the XRT design were reviewed during Phase A. The study focussed particularly on those aspects that have the greatest affect on instrument performance and extended lifetime, on the image quality error budget, and on the camera (mechanical and electrical) interface and the instrument mounting interfaces. The present instrument design differs in some details from that originally proposed. Selection of the XRT for Phase A study was contingent upon the removal of the camera and its associated electronics, and the acceptance of a stringent cost cap. The removal of the electronics left the XRT without control electronics for the instrument mechanisms. A mechanism controller was therefore added. The removal of the camera resulted in major complications to the integration and test plan. After many discussions, it was decided that the system would be less expensive, and the risk of unacceptable performance lower, if we include a focus mechanism. The remainder of the XRT design baseline matches the proposed configuration. Data requirements for the XRT are driven by the science plans, which are based on the physical processes in the solar outer atmosphere. Discussions to date of the XRT observing plan, both alone and in conjunction with the other Solar-B instruments, shows that the XRT needs 2 Gbits of on-board storage, at least one circulating buffer of 640 Mbits, and twelve 10- minute downlinks per day in order to carry out its required programs.

Solar-B X-ray Telescope (XRT) Concept Study Report

NASA Technical Reports Server (NTRS)

Golub, Leon

1999-01-01

The X-ray observations from the Yohkoh SXT provided the greatest step forward in our understanding of the solar corona in nearly two decades. Expanding on the accomplishments of Yohkoh, we believe that the scientific objectives of the Solar-B mission are achieved with a significantly improved X-ray telescope (XRT) similar to the SXT. The Solar-B XRT will have twice the spatial resolution and a broader temperature response, while building on the knowledge gained from the successful Yohkoh mission. We present the scientific justification for this view, discuss the instrumental requirements that flow from the scientific objectives, and describe the instrumentation to meet these requirements. We then provide a detailed discussion of the design activities carried out during Phase A, noting the conclusions that were reached in terms of their implications for the detailed design activities which are now commencing. Details of the instrument that have changed as a result of the Phase A studied are specifically noted, and areas of concern going into Phase B are highlighted. XRT is a grazing-incidence (GI) modified Wolter I X-ray telescope, of 35cm inner diameter and 2.7m focal length. The 2048x2048 back-illuminated CCD (now an ISAS responsibility) has 13.5 micron pixels, corresponding to 1.0 arcsec and giving full Sun field of view. This will be the highest resolution GI X-ray telescope ever flown for Solar coronal studies, and it has been designed specifically to observe both the high and low temperature coronal plasma. A small optical telescope provides visible light images for co-alignment with the Solar-B optical and EUV instruments. The XRT science team is working in close cooperation with our Japanese colleagues in the design and construction of this instrument. All of the expertise and resources of the High Energy and Solar/Stellar Divisions of the Center for Astrophysics are being made available to this program, and our team will carry its full share of responsibility for mission operations, data reduction and education and public outreach. All aspects of the XRT design were reviewed during Phase A. The study focussed particularly on those aspects that have the greatest affect on instrument performance and extended lifetime, on the image quality error budget, and on the camera (mechanical and electrical) interface and the instrument mounting interfaces. The present instrument design differs in some details from that originally proposed. Selection of the XRT for Phase A study was contingent upon the removal of the camera and its associated electronics, and the acceptance of a stringent cost cap. The removal of the electronics left the XRT without control electronics for the instrument mechanisms. A mechanism controller was therefore added. The removal of the camera resulted in major complications to the integration and test plan. After many discussions, it was decided that the system would be less expensive, and the risk of unacceptable performance lower, if we include a focus mechanism. The remainder of the XRT design baseline matches the proposed configuration. Data requirements for the XRT are driven by the science plans, which are based on the physical processes in the solar outer atmosphere. Discussions to date of the XRT observing plan, both alone and in conjunction with the other Solar-B instruments, shows that the XRT needs 2 Gbits of on-board storage, at least one circulating buffer of 640 Mbits, and twelve 10- minute downlinks per day in order to carry out its required programs.

User interfaces in space science instrumentation

NASA Astrophysics Data System (ADS)

McCalden, Alec John

This thesis examines user interaction with instrumentation in the specific context of space science. It gathers together existing practice in machine interfaces with a look at potential future usage and recommends a new approach to space science projects with the intention of maximising their science return. It first takes a historical perspective on user interfaces and ways of defining and measuring the science return of a space instrument. Choices of research methodology are considered. Implementation details such as the concepts of usability, mental models, affordance and presentation of information are described, and examples of existing interfaces in space science are given. A set of parameters for use in analysing and synthesizing a user interface is derived by using a set of case studies of diverse failures and from previous work. A general space science user analysis is made by looking at typical practice, and an interview plus persona technique is used to group users with interface designs. An examination is made of designs in the field of astronomical instrumentation interfaces, showing the evolution of current concepts and including ideas capable of sustaining progress in the future. The parameters developed earlier are then tested against several established interfaces in the space science context to give a degree of confidence in their use. The concept of a simulator that is used to guide the development of an instrument over the whole lifecycle is described, and the idea is proposed that better instrumentation would result from more efficient use of the resources available. The previous ideas in this thesis are then brought together to describe a proposed new approach to a typical development programme, with an emphasis on user interaction. The conclusion shows that there is significant room for improvement in the science return from space instrumentation by attention to the user interface.

Water in the Solar System: The Development of Science Education Curriculum Focused on Planetary Exploration

NASA Astrophysics Data System (ADS)

Edgar, L. A.; Anderson, R. B.; Gaither, T. A.; Milazzo, M. P.; Vaughan, R. G.; Rubino-Hare, L.; Clark, J.; Ryan, S.

2017-12-01

"Water in the Solar System" is an out-of-school time (OST) science education activity for middle school students that was developed as part of the Planetary Learning that Advances the Nexus of Engineering, Technology, and Science (PLANETS) project. The PLANETS project was selected in support of the NASA Science Mission Directorate's Science Education Cooperative Agreement Notice, with the goal of developing and disseminating OST curriculum and related professional development modules that integrate planetary science, technology, and engineering. "Water in the Solar System" is a science activity that addresses the abundance and availability of water in the solar system. The activity consists of three exercises based on the following guiding questions: 1) How much water is there on the Earth? 2) Where can you find water in the solar system? and 3) What properties affect whether or not water can be used by astronauts? The three exercises involve a scaling relationship demonstration about the abundance of useable water on Earth, a card game to explore where water is found in the solar system, and a hands-on exercise to investigate pH and salinity. Through these activities students learn that although there is a lot of water on Earth, most of it is not in a form that is accessible for humans to use. They also learn that most water in the solar system is actually farther from the sun, and that properties such as salinity and pH affect whether water can be used by humans. In addition to content for students, the activity includes background information for educators, and links to in-depth descriptions of the science content. "Water in the Solar System" was developed through collaboration between subject matter experts at the USGS Astrogeology Science Center, and curriculum and professional development experts in the Center for Science Teaching and Learning at Northern Arizona University. Here we describe our process of curriculum development, education objectives of "Water in the Solar System" and lessons learned.

NASA's Best-Observed X-Class Flare of All Time

NASA Image and Video Library

2014-05-07

IBIS can focus in on different wavelengths of light, and so reveal different layers at different heights in the sun's lower atmosphere, the chromosphere. This image shows a region slightly higher than the former one. Credit: Lucia Kleint (BAER Institute), Paul Higgins (Trinity College Dublin, Ireland) -- On March 29, 2014 the sun released an X-class flare. It was observed by NASA's Interface Region Imaging Spectrograph, or IRIS; NASA's Solar Dynamics Observatory, or SDO; NASA's Reuven Ramaty High Energy Solar Spectroscopic Imager, or RHESSI; the Japanese Aerospace Exploration Agency's Hinode; and the National Solar Observatory's Dunn Solar Telescope located at Sacramento Peak in New Mexico. To have a record of such an intense flare from so many observatories is unprecedented. Such research can help scientists better understand what catalyst sets off these large explosions on the sun. Perhaps we may even some day be able to predict their onset and forewarn of the radio blackouts solar flares can cause near Earth - blackouts that can interfere with airplane, ship and military communications. Read more: 1.usa.gov/1kMDQbO Join our Google+ Hangout on May 8 at 2:30pm EST: go.nasa.gov/1mwbBEZ Credit: NASA Goddard NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Convective overshoot at the solar tachocline

NASA Astrophysics Data System (ADS)

Brown, Benjamin; Oishi, Jeffrey S.; Anders, Evan H.; Lecoanet, Daniel; Burns, Keaton; Vasil, Geoffrey M.

2017-08-01

At the base of the solar convection zone lies the solar tachocline. This internal interface is where motions from the unstable convection zone above overshoot and penetrate downward into the stiffly stable radiative zone below, driving gravity waves, mixing, and possibly pumping and storing magnetic fields. Here we study the dynamics of convective overshoot across very stiff interfaces with some properties similar to the internal boundary layer within the Sun. We use the Dedalus pseudospectral framework and study fully compressible dynamics at moderate to high Peclet number and low Mach number, probing a regime where turbulent transport is important, and where the compressible dynamics are similar to those of convective motions in the deep solar interior. We find that the depth of convective overshoot is well described by a simple buoyancy equilibration model, and we consider implications for dynamics at the solar tachocline and for the storage of magnetic fields there by overshooting convection.

The New LASP Interactive Solar IRradiance Datacenter (LISIRD)

NASA Astrophysics Data System (ADS)

Baltzer, T.; Wilson, A.; Lindholm, D. M.; Snow, M. A.; Woodraska, D.; Pankratz, C. K.

2017-12-01

The New LASP Interactive Solar IRradiance Datacenter (LISIRD) The University of Colorado at Boulder's Laboratory for Atmospheric and Space Physics (LASP) has a long history of providing state of the art Solar instrumentation and datasets to the community. In 2005, LASP created a web interface called LISIRD which provided plotting of and access to a number of Solar Irradiance measured and modeled datasets, and it has been used extensively by members of the community both within and outside of LASP. In August of 2017, LASP is set to release a new version of LISIRD for use by anyone interested in viewing and downloading the datasets it serves. This talk will describe the new LISIRD with emphasis on features enabled by it to include: New and more functional plotting interfaces Better dataset browse and search capabilities More datasets Easier to add datasets from a wider array of resources Cleaner interface with better use of screen real estate Much easier to update metadata describing each dataset Much of this capability is leveraged off new infrastructure that will also be touched upon.

Enhancement of photovoltaic performance of flexible perovskite solar cells by means of ionic liquid interface modification in a low temperature all solution process

NASA Astrophysics Data System (ADS)

Chu, Weijing; Yang, Junyou; Jiang, Qinghui; Li, Xin; Xin, Jiwu

2018-05-01

The quality of interface between the electron transport layer (ETL) and perovskite is very crucial to the photovoltaic performance of a flexible perovskite solar cell fabricated under low-temperature process. This work demonstrates a room temperature ionic liquid modification strategy to the interface between ZnO layer and MAPbI3 film for high performance flexible perovskite solar cells based on a PET substrate. [BMIM]BF4 ionic liquid modification can significantly improve the surface quality and wettability of the ZnO ETL, thus greatly increase the charge mobility of ZnO ETL and improve the crystalline of perovskite film based on it. Moreover, the dipolar polarization layer among the ZnO ETL with perovskite, built by modification, can adjust the energy level between the ZnO ETL and perovskite and facilitates the charge extraction. Therefore, an overall power conversion efficiency (PCE) of 12.1% have been achieved under standard illumination, it increases by 1.4 times of the flexible perovskite solar cells on a pristine ZnO ETL.

A solar station in Ica - Mutsumi Ishitsuka: a research center to improve education at the university and schools

NASA Astrophysics Data System (ADS)

Terrazas-Ramos, Raúl

2012-07-01

The San Luis Gonzaga National University of Ica has built a solar station, in collaboration with the Geophysical Institute of Peru, the National Astronomical Observatory of Japan and the Hida Observatory. The Solar Station has the following equipment: a digital Spectrograph Solar Refractor Telescope Takahashi 15 cm aperture, 60 cm reflector telescope aperture, a magnetometer-MAGDAS/CPNM and a Burst Monitor Telescope Solar-FMT (Project CHAIN). These teams support the development of astronomical science and Ica in Peru, likewise contributing to science worldwide. The development of basic science will be guaranteed when university students, professors and researchers work together. The Solar Station will be useful for studying the different levels of university education and also for the general public. The Solar Station will be a good way to spread science in the region through public disclosure.

Interplanetary Lyman α background and the heliospheric interface

NASA Astrophysics Data System (ADS)

Quémerais, Eric; Sander, Bill R.; Clarke, John T.

2006-09-01

We present some recent measurements of the interplanetary Lyman α background which show a clear signature of the heliospheric interface. The Voyager 1 Ultraviolet Spectrometer has measured the variation of the upwind intensity from 1993 to 2006. The derived radial variation of the intensity is clearly slower than what is expected from a hot model computation. This shows that the hydrogen number density increases ahead of the spacecraft, toward the upwind direction. The data also show an abrupt change of slope in 1998 when the Voyager 1 spacecraft was at 65 AU from the sun. This may be linked to temporal variations induced at the heliospheric interface by the variations of solar activity. Interplanetary Lyman α line profiles measured at one AU from the sun also show a clear signature of the heliospheric interface. The SWAN instrument on-board the SOHO spacecraft has studied the line profiles between 1996 and 2002. It was found that the variations seen in line of sight velocities from solar minimum to solar maximum have a larger amplitude than what is derived from hot model computations. The observed features can be better understood when considering that some of the hydrogen atoms crossing the interface region are slowed down and heated. These results are in good agreement with the present models of the interface. Independent spectral observations made by the Hubble Space Telescope in 1995-2001 confirm the SWAN/SOHO measurements.

A Simple and Customizable Web Interface to the Virtual Solar Observatory

NASA Astrophysics Data System (ADS)

Hughitt, V. Keith; Hourcle, J.; Suarez-Sola, I.; Davey, A.

2010-05-01

As the variety and number of solar data sources continue to increase at a rapid rate, the importance of providing methods to search through these sources becomes increasingly important. By taking advantage of the power of modern JavaScript libraries, a new version of the Virtual Solar Observatory's web interface aims to provide a significantly faster and simpler way to explore the multitude of data repositories available. Querying asynchroniously serves not only to eliminates bottlenecks resulting from slow or unresponsive data providers, but also allows for displaying of results as soon as they are returned. Implicit pagination and post-query filtering enables users to work with large result-sets, while a more modular and customizable UI provides a mechanism for customizing both the look-and-feel and behavior of the VSO web interface. Finally, the new web interface features a custom widget system capable of displaying additional tools and information along-side of the standard VSO search form. Interested users can also write their own widgets and submit them for future incorporation into VSO.

One year on VESPA, a community-driven Virtual Observatory in Planetary Science

NASA Astrophysics Data System (ADS)

Erard, S.; Cecconi, B.; Le Sidaner, P.; Rossi, A. P.; Capria, M. T.; Schmitt, B.; Andre, N.; Vandaele, A. C.; Scherf, M.; Hueso, R.; Maattanen, A. E.; Thuillot, W.; Achilleos, N.; Marmo, C.; Santolik, O.; Benson, K.

2016-12-01

The Europlanet H2020 program started on 1/9/2015 for 4 years. It includes an activity to adapt Virtual Observatory (VO) techniques to Planetary Science data called VESPA. The objective is to facilitate searches in big archives as well as sparse databases, to provide simple data access and on-line visualization, and to allow small data providers to make their data available in an interoperable environment with minimum effort. The VESPA system, based on a prototype developed in a previous program [1], has been hugely improved during the first year of Europlanet H2020: the infrastructure has been upgraded to describe data in many fields more accurately; the main user search interface (http://vespa.obspm.fr) has been redesigned to provide more flexibility; alternative ways to access Planetary Science data services from VO tools are being implemented in addition to receiving data from the main interface; VO tools are being improved to handle specificities of Solar System data, e.g. measurements in reflected light, coordinate systems, etc. Existing data services have been updated, and new ones have been designed. The global objective (50 data services) is already overstepped, with 54 services open or being finalized. A procedure to install data services has been documented, and hands-on sessions are organized twice a year at EGU and EPSC; this is intended to favour the installation of services by individual research teams, e.g. to distribute derived data related to a published study. In complement, regular discussions are held with big data providers, starting with space agencies (IPDA). Common projects with ESA and NASA's PDS have been engaged, which should lead to a connection between PDS4 and EPN-TAP. In parallel, a Solar System Interest Group has been decided in IVOA; the goal is here to adapt existing astronomy standards to Planetary Science.Future steps will include the development of a connection between the VO world and GIS tools, and integration of Heliophysics, planetary plasma and mineral spectroscopy data. The Europlanet 2020 Research Infrastructure project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 654208. [1] Erard et al 2014, Astronomy & Computing 7-8, 71-80. http://arxiv.org/abs/1407.4886

NASA's Best-Observed X-Class Flare of All Time

NASA Image and Video Library

2014-05-07

Like almost all solar observatories, NASA's IRIS can provide images of different layers of the sun's atmosphere, which together create a whole picture of what's happening. This image shows light at a wavelength of 1400 Angstrom, which highlights material some 650 miles above the sun's surface. The vertical line in the middle shows the slit for IRIS's spectrograph, which can separate light into its many wavelengths to provide even more information about the temperature and velocity of material during a flare. Credit: NASA/IRIS/Goddard Space Flight Center -- On March 29, 2014 the sun released an X-class flare. It was observed by NASA's Interface Region Imaging Spectrograph, or IRIS; NASA's Solar Dynamics Observatory, or SDO; NASA's Reuven Ramaty High Energy Solar Spectroscopic Imager, or RHESSI; the Japanese Aerospace Exploration Agency's Hinode; and the National Solar Observatory's Dunn Solar Telescope located at Sacramento Peak in New Mexico. To have a record of such an intense flare from so many observatories is unprecedented. Such research can help scientists better understand what catalyst sets off these large explosions on the sun. Perhaps we may even some day be able to predict their onset and forewarn of the radio blackouts solar flares can cause near Earth - blackouts that can interfere with airplane, ship and military communications. Read more: 1.usa.gov/1kMDQbO Join our Google+ Hangout on May 8 at 2:30pm EST: go.nasa.gov/1mwbBEZ Credit: NASA Goddard NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

NASA's Best-Observed X-Class Flare of All Time

NASA Image and Video Library

2014-05-07

The March 29, 2014, X-class flare appears as a bright light on the upper right in this image from SDO, showing light in the 304 Angstrom wavelength. This wavelength shows material on the sun in what's called the transition region, where the chromosphere transitions into the upper solar atmosphere, the corona. Some light of the flare is clearly visible, but the flare appears brighter in other images that show hotter temperature material. Credit: NASA/SDO/AIA -- On March 29, 2014 the sun released an X-class flare. It was observed by NASA's Interface Region Imaging Spectrograph, or IRIS; NASA's Solar Dynamics Observatory, or SDO; NASA's Reuven Ramaty High Energy Solar Spectroscopic Imager, or RHESSI; the Japanese Aerospace Exploration Agency's Hinode; and the National Solar Observatory's Dunn Solar Telescope located at Sacramento Peak in New Mexico. To have a record of such an intense flare from so many observatories is unprecedented. Such research can help scientists better understand what catalyst sets off these large explosions on the sun. Perhaps we may even some day be able to predict their onset and forewarn of the radio blackouts solar flares can cause near Earth - blackouts that can interfere with airplane, ship and military communications. Read more: 1.usa.gov/1kMDQbO Join our Google+ Hangout on May 8 at 2:30pm EST: go.nasa.gov/1mwbBEZ NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Research | Photovoltaic Research | NREL

Science.gov Websites

-V cells Hybrid tandems Polycrystalline Thin-Film PV CdTe solar cells CIGS solar cells Perovskites and Organic PV Perovskite solar cells Organic PV solar cells Advanced Materials, Devices, and Science Interfacial and Surface Science Reliability and Engineering Real-Time PV and Solar Resource

Photocharge accumulation and recombination in perovskite solar cells regarding device performance and stability

NASA Astrophysics Data System (ADS)

Li, Yusheng; Li, Yiming; Shi, Jiangjian; Li, Hongshi; Zhang, Huiyin; Wu, Jionghua; Li, Dongmei; Luo, Yanhong; Wu, Huijue; Meng, Qingbo

2018-01-01

Photocharge accumulation and recombination in perovskite solar cells have been systematically investigated in this paper by electrochemical spectroscopy and transient photocurrent/photovoltage methods. It is found that the non-equilibrium photocharges stored in the selective charge transport layers follow a backward recombination mechanism. That is, the photocharges are first captured by the interface defects corresponding to the fast photovoltage decay, while the bulk charge recombination instead of the diffusion process dominates the slow photovoltage decay process. Further investigation reveals that the device degradation preferentially takes place at the interface under working conditions, which thus can confirm the importance of interface engineering to enhance the device stability.

Accessing SDO data in a pipeline environment using the VSO WSDL/SOAP interface

NASA Astrophysics Data System (ADS)

Suarez Sola, F. I.; Hourcle, J. A.; Amezcua, A.; Bogart, R.; Davey, A. R.; Gurman, J. B.; Hill, F.; Hughitt, V. K.; Martens, P. C.; Spencer, J.; Vso Team

2010-12-01

As part of the Virtual Solar Observatory (VSO) effort to support the Solar Dynamics Observatory (SDO) data, the VSO has worked on bringing up to date its WSDL document and SOAP interface to make it compatible with most widely used web services core engines. (E.g. axis2, jws, etc.) In this presentation we will explore the possibilities available for searching and/or fetching data within pipeline code. We will explain some of the WSDL/VSO-SDO interface intricacies and show how the vast amount of data that is available via the VSO can be tapped via IDL, Java, Perl or C in an uncomplicated way.

Self Assembly and Interface Engineering of Organic Functional Materials for High Performance Polymer Solar Cells

NASA Astrophysics Data System (ADS)

Jen, Alex

2010-03-01

The performance of polymer solar cells are strongly dependent on the efficiency of light harvesting, exciton dissociation, charge transport, and charge collection at the metal/organic, metal/metal oxide, and organic/metal oxide interfaces. To improve the device performance, two parallel approaches were used: 1) developing novel low band gap conjugated polymers with good charge-transporting properties and 2) modifying the interfaces between the organic/metal oxide and organic/metal layers with functional self-assembling monolayers to tune their energy barriers. Moreover, the molecule engineering approach was also used to tune the energy level, charge mobility, and morphology of organic semiconductors.

On the Performance of Multi-Instrument Solar Flare Observations During Solar Cycle 24

NASA Astrophysics Data System (ADS)

Milligan, Ryan O.; Ireland, Jack

2018-02-01

The current fleet of space-based solar observatories offers us a wealth of opportunities to study solar flares over a range of wavelengths. Significant advances in our understanding of flare physics often come from coordinated observations between multiple instruments. Consequently, considerable efforts have been, and continue to be, made to coordinate observations among instruments ( e.g. through the Max Millennium Program of Solar Flare Research). However, there has been no study to date that quantifies how many flares have been observed by combinations of various instruments. Here we describe a technique that retrospectively searches archival databases for flares jointly observed by the Ramaty High Energy Solar Spectroscopic Imager (RHESSI), Solar Dynamics Observatory (SDO)/ EUV Variability Experiment (EVE - Multiple EUV Grating Spectrograph (MEGS)-A and -B, Hinode/( EUV Imaging Spectrometer, Solar Optical Telescope, and X-Ray Telescope), and Interface Region Imaging Spectrograph (IRIS). Out of the 6953 flares of GOES magnitude C1 or greater that we consider over the 6.5 years after the launch of SDO, 40 have been observed by 6 or more instruments simultaneously. Using each instrument's individual rate of success in observing flares, we show that the numbers of flares co-observed by 3 or more instruments are higher than the number expected under the assumption that the instruments operated independently of one another. In particular, the number of flares observed by larger numbers of instruments is much higher than expected. Our study illustrates that these missions often acted in cooperation, or at least had aligned goals. We also provide details on an interactive widget ( Solar Flare Finder), now available in SSWIDL, which allows a user to search for flaring events that have been observed by a chosen set of instruments. This provides access to a broader range of events in order to answer specific science questions. The difficulty in scheduling coordinated observations for solar-flare research is discussed with respect to instruments projected to begin operations during Solar Cycle 25, such as the Daniel K. Inouye Solar Telescope, Solar Orbiter, and Parker Solar Probe.

Achieving 14.4% Alcohol-Based Solution-Processed Cu(In,Ga)(S,Se)2 Thin Film Solar Cell through Interface Engineering.

PubMed

Park, Gi Soon; Chu, Van Ben; Kim, Byoung Woo; Kim, Dong-Wook; Oh, Hyung-Suk; Hwang, Yun Jeong; Min, Byoung Koun

2018-03-28

An optimization of band alignment at the p-n junction interface is realized on alcohol-based solution-processed Cu(In,Ga)(S,Se) 2 (CIGS) thin film solar cells, achieving a power-conversion-efficiency (PCE) of 14.4%. To obtain a CIGS thin film suitable for interface engineering, we designed a novel "3-step chalcogenization process" for Cu 2- x Se-derived grain growth and a double band gap grading structure. Considering S-rich surface of the CIGS thin film, an alternative ternary (Cd,Zn)S buffer layer is adopted to build favorable "spike" type conduction band alignment instead of "cliff" type. Suppression of interface recombination is elucidated by comparing recombination activation energies using a dark J- V- T analysis.

First-Principles Approach to Energy Level Alignment at Aqueous Semiconductor Interfaces

NASA Astrophysics Data System (ADS)

Hybertsen, Mark

2015-03-01

We have developed a first principles method to calculate the energy level alignment between semiconductor band edges and reference energy levels at aqueous interfaces. This alignment is fundamental to understand the electrochemical characteristics of any semiconductor electrode in general and the potential for photocatalytic activity in particular. For example, in the search for new photo-catalytic materials, viable candidates must demonstrate both efficient absorption of the solar spectrum and an appropriate alignment of the band edge levels in the semiconductor to the redox levels for the target reactions. In our approach, the interface-specific contribution to the electrostatic step across the interface is evaluated using density functional theory (DFT) based molecular dynamics to sample the physical interface structure and the corresponding change in the electrostatic potential at the interface. The reference electronic levels in the semiconductor and in the water are calculated using the GW approach, which naturally corrects for errors inherent in the use of Kohn-Sham energy eigenvalues to approximate the electronic excitation energies in each material. Taken together, our calculations provide the alignment of the semiconductor valence band edge to the centroid of the highest occupied 1b1 level in water. The known relationship of the 1b1 level to the normal hydrogen electrode completes the connection to electrochemical levels. We discuss specific results for GaN, ZnO, and TiO2. The effect of interface structural motifs, such as different degrees of water dissociation, and of dynamical characteristics, will be presented together with available experimental data. Work supported by the US Department of Energy, Office of Basic Energy Sciences under Contract No. DE-AC02-98CH10886.

KSC-2013-2730

NASA Image and Video Library

2013-06-13

VANDENBERG ABF, Calif. - The Orbital Sciences Pegasus XL rocket that will lift NASA's IRIS solar observatory into orbit is moved from a hangar onto a transporter at Vandenberg Air Force Base. IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch from Vandenberg June 26. IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: VAFB/Randy Beaudoin

KSC-2013-2731

NASA Image and Video Library

2013-06-13

VANDENBERG ABF, Calif. - The Orbital Sciences Pegasus XL rocket that will lift NASA's IRIS solar observatory into orbit is moved from a hangar onto a transporter at Vandenberg Air Force Base. IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch from Vandenberg June 26. IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: VAFB/Randy Beaudoin

KSC-2013-2726

NASA Image and Video Library

2013-06-13

VANDENBERG ABF, Calif. - The Orbital Sciences Pegasus XL rocket that will lift NASA's IRIS solar observatory into orbit is moved from a hangar onto a transporter at Vandenberg Air Force Base. IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch from Vandenberg June 26. IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: VAFB/Randy Beaudoin

KSC-2013-2733

NASA Image and Video Library

2013-06-13

VANDENBERG ABF, Calif. - The Orbital Sciences Pegasus XL rocket that will lift NASA's IRIS solar observatory into orbit is moved from a hangar onto a transporter at Vandenberg Air Force Base. IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch from Vandenberg June 26. IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: VAFB/Randy Beaudoin

KSC-2013-2734

NASA Image and Video Library

2013-06-13

VANDENBERG ABF, Calif. - The Orbital Sciences Pegasus XL rocket that will lift NASA's IRIS solar observatory into orbit is moved from a hangar onto a transporter at Vandenberg Air Force Base. IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch from Vandenberg June 26. IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: VAFB/Randy Beaudoin

KSC-2013-2732

NASA Image and Video Library

2013-06-13

VANDENBERG ABF, Calif. - The Orbital Sciences Pegasus XL rocket that will lift NASA's IRIS solar observatory into orbit is moved from a hangar onto a transporter at Vandenberg Air Force Base. IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch from Vandenberg June 26. IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: VAFB/Randy Beaudoin

KSC-2013-2669

NASA Image and Video Library

2013-06-11

VANDENBERG ABF, Calif. - The Orbital Sciences Pegasus XL rocket that will lift NASA's IRIS solar observatory into orbit in June is seen in a hangar at Vandenberg Air Force Base. IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch from Vandenberg June 26. IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: VAFB/Randy Beaudoin

KSC-2013-2668

NASA Image and Video Library

2013-06-11

VANDENBERG ABF, Calif. - The Orbital Sciences Pegasus XL rocket that will lift NASA's IRIS solar observatory into orbit in June is seen in a hangar at Vandenberg Air Force Base. IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch from Vandenberg June 26. IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: VAFB/Randy Beaudoin

KSC-2013-2666

NASA Image and Video Library

2013-06-11

VANDENBERG ABF, Calif. - The Orbital Sciences Pegasus XL rocket that will lift NASA's IRIS solar observatory into orbit in June is seen in a hangar at Vandenberg Air Force Base. IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch from Vandenberg June 26. IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: VAFB/Randy Beaudoin

KSC-2013-2665

NASA Image and Video Library

2013-06-11

VANDENBERG ABF, Calif. - The Orbital Sciences Pegasus XL rocket that will lift NASA's IRIS solar observatory into orbit in June is seen in a hangar at Vandenberg Air Force Base. IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch from Vandenberg June 26. IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: VAFB/Randy Beaudoin

KSC-2013-2667

NASA Image and Video Library

2013-06-11

VANDENBERG ABF, Calif. - The Orbital Sciences Pegasus XL rocket that will lift NASA's IRIS solar observatory into orbit in June is seen in a hangar at Vandenberg Air Force Base. IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch from Vandenberg June 26. IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: VAFB/Randy Beaudoin

KSC-2013-2727

NASA Image and Video Library

2013-06-13

VANDENBERG ABF, Calif. - The Orbital Sciences Pegasus XL rocket that will lift NASA's IRIS solar observatory into orbit is moved from a hangar onto a transporter at Vandenberg Air Force Base. IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch from Vandenberg June 26. IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: VAFB/Randy Beaudoin

Solar Eclipse: Concept of “Science” and “Language” Literacy

NASA Astrophysics Data System (ADS)

Haristiani, N.; Zaen, R.; Nandiyanto, A. B. D.; Rusmana, A. N.; Azis, F.; Danuwijaya, A. A.; Abdullah, A. G.

2018-02-01

The purpose of this study was to evaluate the concept of science and language literacy of solar eclipse. The study was conducted through a survey to 250 students with different ages (from 17 to 23 years old), grades, and majors in Universitas Pendidikan Indonesia. The survey was completed with a questionnaire consisting of 41 questions. In the case of the language literacy, experimental results showed that various expressions in facing the solar eclipse phenomenon are found. Relating to the science literacy, most students have good science understanding to the solar eclipse phenomenon. In conclusion, the understanding about the solar eclipse is affected by formal science education and religion understanding that they have been accepted since their childhood. These factors have also influenced the belief of Indonesian people to the solar eclipse myth and the way of expressions a language literacy.

Solar Energy in the School Curriculum: Giving New Life to Old Science.

ERIC Educational Resources Information Center

Hibbert, Oliver D.

1984-01-01

Describes some simple solar energy experiments, reviews real life examples of solar energy, and lists areas where solar energy can fit into existing school science curricula. Instructions for making equipment needed, a discussion of recent developments in thermal systems and photovoltaics, and a bibliography are included. (JN)

The development and operation of the international solar-terrestrial physics central data handling facility

NASA Technical Reports Server (NTRS)

Lehtonen, Kenneth

1994-01-01

The National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) International Solar-Terrestrial Physics (ISTP) Program is committed to the development of a comprehensive, multi-mission ground data system which will support a variety of national and international scientific missions in an effort to study the flow of energy from the sun through the Earth-space environment, known as the geospace. A major component of the ISTP ground data system is an ISTP-dedicated Central Data Handling Facility (CDHF). Acquisition, development, and operation of the ISTP CDHF were delegated by the ISTP Project Office within the Flight Projects Directorate to the Information Processing Division (IPD) within the Mission Operations and Data Systems Directorate (MO&DSD). The ISTP CDHF supports the receipt, storage, and electronic access of the full complement of ISTP Level-zero science data; serves as the linchpin for the centralized processing and long-term storage of all key parameters generated either by the ISTP CDHF itself or received from external, ISTP Program approved sources; and provides the required networking and 'science-friendly' interfaces for the ISTP investigators. Once connected to the ISTP CDHF, the online catalog of key parameters can be browsed from their remote processing facilities for the immediate electronic receipt of selected key parameters using the NASA Science Internet (NSI), managed by NASA's Ames Research Center. The purpose of this paper is twofold: (1) to describe how the ISTP CDHF was successfully implemented and operated to support initially the Japanese Geomagnetic Tail (GEOTAIL) mission and correlative science investigations, and (2) to describe how the ISTP CDHF has been enhanced to support ongoing as well as future ISTP missions. Emphasis will be placed on how various project management approaches were undertaken that proved to be highly effective in delivering an operational ISTP CDHF to the Project on schedule and within budget. Examples to be discussed include: the development of superior teams; the use of Defect Causal Analysis (DCA) concepts to improve the software development process in a pilot Total Quality Management (TQM) initiative; and the implementation of a robust architecture that will be able to support the anticipated growth in the ISTP Program science requirements with only incremental upgrades to the baseline system. Further examples include the use of automated data management software and the implementation of Government and/or industry standards, whenever possible, into the hardware and software development life-cycle. Finally, the paper will also report on several new technologies (for example, the installation of a Fiber Data Distribution Interface network) that were successfully employed.

Physical criteria for the interface passivation layer in hydrogenated amorphous/crystalline silicon heterojunction solar cell

NASA Astrophysics Data System (ADS)

Zhao, Lei; Wang, Guanghong; Diao, Hongwei; Wang, Wenjing

2018-01-01

AFORS-HET (automat for simulation of heterostructures) simulation was utilized to explore the physical criteria for the passivation layer in hydrogenated amorphous/crystalline silicon heterojunction (SHJ) solar cells, by systematically investigating the solar cell current density-voltage (J-V) performance as a function of the interface defect density (D it) at the passivation layer/c-Si hetero-interface, the thickness (t) of the passivation layer, the bandgap (E g) of the passivation layer, and the density of dangling bond states (D db)/band tail states (D bt) in the band gap of the passivation layer. The corresponding impact regulations were presented clearly. Except for D it, the impacts of D db, D bt and E g are strongly dependent on the passivation layer thickness t. While t is smaller than 4-5 nm, the solar cell performance is less sensitive to the variation of D db, D bt and E g. Low D it at the a-Si:H/c-Si interface and small thickness t are the critical criteria for the passivation layer in such a case. However, if t has to be relatively larger, the microstructure, i.e. the material quality, including D db, D bt and E g, of the passivation layer should be controlled carefully. The mechanisms involved were analyzed and some applicable methods to prepare the passivation layer were proposed.

The role of high work-function metallic nanodots on the performance of a-Si:H solar cells: offering ohmic contact to light trapping.

PubMed

Kim, Jeehwan; Abou-Kandil, Ahmed; Fogel, Keith; Hovel, Harold; Sadana, Devendra K

2010-12-28

Addition of carbon into p-type "window" layers in hydrogenated amorphous silicon (a-Si:H) solar cells enhances short circuit currents and open circuit voltages by a great deal. However, a-Si:H solar cells with high carbon-doped "window" layers exhibit poor fill factors due to a Schottky barrier-like impedance at the interface between a-SiC:H windows and transparent conducting oxides (TCO), although they show maximized short circuit currents and open circuit voltages. The impedance is caused by an increasing mismatch between the work function of TCO and that of p-type a-SiC:H. Applying ultrathin high-work-function metals at the interface between the two materials results in an effective lowering of the work function mismatch and a consequent ohmic behavior. If the metal layer is sufficiently thin, then it forms nanodots rather than a continuous layer which provides light-scattering effect. We demonstrate 31% efficiency enhancement by using high-work-function materials for engineering the work function at the key interfaces to raise fill factors as well as photocurrents. The use of metallic interface layers in this work is a clear contrast to previous work where attempts were made to enhance the photocurrent using plasmonic metal nanodots on the solar cell surface.

Space Solar Power Management and Distribution (PMAD)

NASA Technical Reports Server (NTRS)

Lynch, Thomas H.

2000-01-01

This paper presents, in viewgraph form, SSP PMAD (Space Solar Power Management and Distribution). The topics include: 1) Architecture; 2) Backside Thermal View; 3) Solar Array Interface; 4) Transformer design and risks; 5) Twelve phase rectifier; 6) Antenna (80V) Converters; 7) Distribution Cables; 8) Weight Analysis; and 9) PMAD Summary.

How the charge-neutrality level of interface states controls energy level alignment in cathode contacts of organic bulk-heterojunction solar cells.

PubMed

Guerrero, Antonio; Marchesi, Luís F; Boix, Pablo P; Ruiz-Raga, Sonia; Ripolles-Sanchis, Teresa; Garcia-Belmonte, Germà; Bisquert, Juan

2012-04-24

Electronic equilibration at the metal-organic interface, leading to equalization of the Fermi levels, is a key process in organic optoelectronic devices. How the energy levels are set across the interface determines carrier extraction at the contact and also limits the achievable open-circuit voltage under illumination. Here, we report an extensive investigation of the cathode energy equilibration of organic bulk-heterojunction solar cells. We show that the potential to balance the mismatch between the cathode metal and the organic layer Fermi levels is divided into two contributions: spatially extended band bending in the organic bulk and voltage drop at the interface dipole layer caused by a net charge transfer. We scan the operation of the cathode under a varied set of conditions, using metals of different work functions in the range of ∼2 eV, different fullerene acceptors, and several cathode interlayers. The measurements allow us to locate the charge-neutrality level within the interface density of sates and calculate the corresponding dipole layer strength. The dipole layer withstands a large part of the total Fermi level mismatch when the polymer:fullerene blend ratio approaches ∼1:1, producing the practical alignment between the metal Fermi level and the charge-neutrality level. Origin of the interface states is linked with fullerene reduced molecules covering the metal contact. The dipole contribution, and consequently the band bending, is highly sensitive to the nature and amount of fullerene molecules forming the interface density of states. Our analysis provides a detailed picture of the evolution of the potentials in the bulk and the interface of the solar cell when forward voltage is applied or when photogeneration takes place.

Embracing Open Software Development in Solar Physics

NASA Astrophysics Data System (ADS)

Hughitt, V. K.; Ireland, J.; Christe, S.; Mueller, D.

2012-12-01

We discuss two ongoing software projects in solar physics that have adopted best practices of the open source software community. The first, the Helioviewer Project, is a powerful data visualization tool which includes online and Java interfaces inspired by Google Maps (tm). This effort allows users to find solar features and events of interest, and download the corresponding data. Having found data of interest, the user now has to analyze it. The dominant solar data analysis platform is an open-source library called SolarSoft (SSW). Although SSW itself is open-source, the programming language used is IDL, a proprietary language with licensing costs that are prohibative for many institutions and individuals. SSW is composed of a collection of related scripts written by missions and individuals for solar data processing and analysis, without any consistent data structures or common interfaces. Further, at the time when SSW was initially developed, many of the best software development processes of today (mirrored and distributed version control, unit testing, continuous integration, etc.) were not standard, and have not since been adopted. The challenges inherent in developing SolarSoft led to a second software project known as SunPy. SunPy is an open-source Python-based library which seeks to create a unified solar data analysis environment including a number of core datatypes such as Maps, Lightcurves, and Spectra which have consistent interfaces and behaviors. By taking advantage of the large and sophisticated body of scientific software already available in Python (e.g. SciPy, NumPy, Matplotlib), and by adopting many of the best practices refined in open-source software development, SunPy has been able to develop at a very rapid pace while still ensuring a high level of reliability. The Helioviewer Project and SunPy represent two pioneering technologies in solar physics - simple yet flexible data visualization and a powerful, new data analysis environment. We discuss the development of both these efforts and how they are beginning to influence the solar physics community.

Overview of NASA Finesse (Field Investigations to Enable Solar System Science and Exploration) Science and Exploration Project

NASA Technical Reports Server (NTRS)

Heldmann, J. L.; Lim, D.S.S.; Hughes, S.; Nawotniak, S. Kobs; Garry, B.; Sears, D.; Neish, C.; Osinski, G. R.; Hodges, K.; Downs, M.;

Next Generation Space Telescope Integrated Science Module Data System

NASA Technical Reports Server (NTRS)

Schnurr, Richard G.; Greenhouse, Matthew A.; Jurotich, Matthew M.; Whitley, Raymond; Kalinowski, Keith J.; Love, Bruce W.; Travis, Jeffrey W.; Long, Knox S.

1999-01-01

The Data system for the Next Generation Space Telescope (NGST) Integrated Science Module (ISIM) is the primary data interface between the spacecraft, telescope, and science instrument systems. This poster includes block diagrams of the ISIM data system and its components derived during the pre-phase A Yardstick feasibility study. The poster details the hardware and software components used to acquire and process science data for the Yardstick instrument compliment, and depicts the baseline external interfaces to science instruments and other systems. This baseline data system is a fully redundant, high performance computing system. Each redundant computer contains three 150 MHz power PC processors. All processors execute a commercially available real time multi-tasking operating system supporting, preemptive multi-tasking, file management and network interfaces. These six processors in the system are networked together. The spacecraft interface baseline is an extension of the network, which links the six processors. The final selection for Processor busses, processor chips, network interfaces, and high-speed data interfaces will be made during mid 2002.

Graphical User Interface Programming in Introductory Computer Science.

ERIC Educational Resources Information Center

Skolnick, Michael M.; Spooner, David L.

Modern computing systems exploit graphical user interfaces for interaction with users; as a result, introductory computer science courses must begin to teach the principles underlying such interfaces. This paper presents an approach to graphical user interface (GUI) implementation that is simple enough for beginning students to understand, yet…

Bringing Real Solar Physics to the High School Classroom

NASA Astrophysics Data System (ADS)

Seaton, Daniel

2006-06-01

UNH's Partnership for Research Opportunities to Benefit Education (PROBE) project sends graduate students into high school classrooms across New Hampshire in order to help introduce students to authentic scientific inquiry. As one of ten graduate fellows, I worked with students in in ninth through twelfth grades in physical science, physics, earth science, and astronomy classes; helping students carry out individual and class projects on physics and solar physics. Projects related to solar physics included the production and analysis of plasma using a microwave oven, measurement of the solar constant, measurement of the solar rotation rate, solar spectroscopy, analysis of data from TRACE and SOHO, and the construction of various solar-powered devices. This work was generously supported by a grant from the National Science Foundation's GK-12 initiative (NSF#0338277).

Toward a Virtual Solar Observatory: Starting Before the Petabytes Fall

NASA Technical Reports Server (NTRS)

Gurman, J. B.; Fisher, Richard R. (Technical Monitor)

2002-01-01

NASA is currently engaged in the study phase of a modest effort to establish a Virtual Solar Observatory (VSO). The VSO would serve ground- and space-based solar physics data sets from a distributed network of archives through a small number of interfaces to the scientific community. The basis of this approach, as of all planned virtual observatories, is the translation of metadata from the various sources via source-specific dictionaries so the user will not have to distinguish among keyword usages. A single Web interface should give access to all the distributed data. We present the current status of the VSO, its initial scope, and its relation to the European EGSO effort.

The fast development of solar terrestrial sciences in Taiwan

NASA Astrophysics Data System (ADS)

Liu, Jann-Yenq; Chang, Loren Chee-Wei; Chao, Chi-Kuang; Chen, Ming-Quey; Chu, Yen-Hsyang; Hau, Lin-Ni; Huang, Chien-Ming; Kuo, Cheng-Ling; Lee, Lou-Chuang; Lyu, Ling-Hsiao; Lin, Chia-Hsien; Pan, Chen-Jeih; Shue, Jih-Hong; Su, Ching-Lun; Tsai, Lung-Chih; Yang, Ya-Hui; Lin, Chien-Hung; Hsu, Rue-Ron; Su, Han-Tzong

2016-12-01

In Taiwan, research and education of solar terrestrial sciences began with a ground-based ionosonde operated by Ministry of Communications in 1952 and courses of ionospheric physics and space physics offered by National Central University (NCU) in 1959, respectively. Since 1990, to enhance both research and education, the Institute of Space Science at NCU has been setting up and operating ground-based observations of micropulsations, very high-frequency radar, low-latitude ionospheric tomography network, high-frequency Doppler sounder, digital ionosondes, and total electron content (TEC) derived from ground-based GPS receivers to study the morphology of the ionosphere for diurnal, seasonal, geophysical, and solar activity variations, as well as the ionosphere response to solar flares, solar wind, solar eclipses, magnetic storms, earthquakes, tsunami, and so on. Meanwhile, to have better understanding on physics and mechanisms, model simulations for the heliosphere, solar wind, magnetosphere, and ionosphere are also introduced and developed. After the 21 September 1999 Mw7.6 Chi-Chi earthquake, seismo-ionospheric precursors and seismo-traveling ionospheric disturbances induced by earthquakes become the most interesting and challenging research topics of the world. The development of solar terrestrial sciences grows even much faster after National Space Origination has been launching a series of FORMOSAT satellites since 1999. ROCSAT-1 (now renamed FORMOSAT-1) measures the ion composition, density, temperature, and drift velocity at the 600-km altitude in the low-latitude ionosphere; FORMOSAT-2 is to investigate lightning-induced transient luminous events, polar aurora, and upper atmospheric airglow, and FORMOSAT-3 probes ionospheric electron density profiles of the globe. In the near future, FORMOSAT-5 and FORMOSAT-7/COSMIC-2 will be employed for studying solar terrestrial sciences. These satellite missions play an important role on the recent development of solar terrestrial sciences in Taiwan.

Solar Wind Electrons Alphas and Protons (SWEAP) Investigation: Design of the Solar Wind and Coronal Plasma Instrument Suite for Solar Probe Plus

NASA Astrophysics Data System (ADS)

Kasper, Justin C.; Abiad, Robert; Austin, Gerry; Balat-Pichelin, Marianne; Bale, Stuart D.; Belcher, John W.; Berg, Peter; Bergner, Henry; Berthomier, Matthieu; Bookbinder, Jay; Brodu, Etienne; Caldwell, David; Case, Anthony W.; Chandran, Benjamin D. G.; Cheimets, Peter; Cirtain, Jonathan W.; Cranmer, Steven R.; Curtis, David W.; Daigneau, Peter; Dalton, Greg; Dasgupta, Brahmananda; DeTomaso, David; Diaz-Aguado, Millan; Djordjevic, Blagoje; Donaskowski, Bill; Effinger, Michael; Florinski, Vladimir; Fox, Nichola; Freeman, Mark; Gallagher, Dennis; Gary, S. Peter; Gauron, Tom; Gates, Richard; Goldstein, Melvin; Golub, Leon; Gordon, Dorothy A.; Gurnee, Reid; Guth, Giora; Halekas, Jasper; Hatch, Ken; Heerikuisen, Jacob; Ho, George; Hu, Qiang; Johnson, Greg; Jordan, Steven P.; Korreck, Kelly E.; Larson, Davin; Lazarus, Alan J.; Li, Gang; Livi, Roberto; Ludlam, Michael; Maksimovic, Milan; McFadden, James P.; Marchant, William; Maruca, Bennet A.; McComas, David J.; Messina, Luciana; Mercer, Tony; Park, Sang; Peddie, Andrew M.; Pogorelov, Nikolai; Reinhart, Matthew J.; Richardson, John D.; Robinson, Miles; Rosen, Irene; Skoug, Ruth M.; Slagle, Amanda; Steinberg, John T.; Stevens, Michael L.; Szabo, Adam; Taylor, Ellen R.; Tiu, Chris; Turin, Paul; Velli, Marco; Webb, Gary; Whittlesey, Phyllis; Wright, Ken; Wu, S. T.; Zank, Gary

2016-12-01

The Solar Wind Electrons Alphas and Protons (SWEAP) Investigation on Solar Probe Plus is a four sensor instrument suite that provides complete measurements of the electrons and ionized helium and hydrogen that constitute the bulk of solar wind and coronal plasma. SWEAP consists of the Solar Probe Cup (SPC) and the Solar Probe Analyzers (SPAN). SPC is a Faraday Cup that looks directly at the Sun and measures ion and electron fluxes and flow angles as a function of energy. SPAN consists of an ion and electron electrostatic analyzer (ESA) on the ram side of SPP (SPAN-A) and an electron ESA on the anti-ram side (SPAN-B). The SPAN-A ion ESA has a time of flight section that enables it to sort particles by their mass/charge ratio, permitting differentiation of ion species. SPAN-A and -B are rotated relative to one another so their broad fields of view combine like the seams on a baseball to view the entire sky except for the region obscured by the heat shield and covered by SPC. Observations by SPC and SPAN produce the combined field of view and measurement capabilities required to fulfill the science objectives of SWEAP and Solar Probe Plus. SWEAP measurements, in concert with magnetic and electric fields, energetic particles, and white light contextual imaging will enable discovery and understanding of solar wind acceleration and formation, coronal and solar wind heating, and particle acceleration in the inner heliosphere of the solar system. SPC and SPAN are managed by the SWEAP Electronics Module (SWEM), which distributes power, formats onboard data products, and serves as a single electrical interface to the spacecraft. SWEAP data products include ion and electron velocity distribution functions with high energy and angular resolution. Full resolution data are stored within the SWEM, enabling high resolution observations of structures such as shocks, reconnection events, and other transient structures to be selected for download after the fact. This paper describes the implementation of the SWEAP Investigation, the driving requirements for the suite, expected performance of the instruments, and planned data products, as of mission preliminary design review.

Solar System Observations with the James Webb Space Telescope

NASA Technical Reports Server (NTRS)

Norwood, James; Hammel, Heidi; Milam, Stefanie; Stansberry, John; Lunine, Jonathan; Chanover, Nancy; Hines, Dean; Sonneborn, George; Tiscareno, Matthew; Brown, Michael;

Solar System Observations with JWST

NASA Technical Reports Server (NTRS)

Norwood, James; Hammel, Heidi; Milam, Stefanie; Stansberry, John; Lunine, Jonathan; Chanover, Nancy; Hines, Dean; Sonneborn, George; Tiscareno, Matthew; Brown, Michael;

A Combined Theoretical and Experimental Study of Dissociation of Charge Transfer States at the Donor-Acceptor Interface of Organic Solar Cells.

PubMed

Tscheuschner, Steffen; Bässler, Heinz; Huber, Katja; Köhler, Anna

2015-08-13

The observation that in efficient organic solar cells almost all electron-hole pairs generated at the donor-acceptor interface escape from their mutual coulomb potential remains to be a conceptual challenge. It has been argued that it is the excess energy dissipated in the course of electron or hole transfer at the interface that assists this escape process. The current work demonstrates that this concept is unnecessary to explain the field dependence of electron-hole dissociation. It is based upon the formalism developed by Arkhipov and co-workers as well as Baranovskii and co-workers. The key idea is that the binding energy of the dissociating "cold" charge-transfer state is reduced by delocalization of the hole along the polymer chain, quantified in terms of an "effective mass", as well as the fractional strength of dipoles existent at the interface in the dark. By covering a broad parameter space, we determine the conditions for efficient electron-hole dissociation. Spectroscopy of the charge-transfer state on bilayer solar cells as well as measurements of the field dependence of the dissociation yield over a broad temperature range support the theoretical predictions.

A dynamic Monte Carlo study of anomalous current voltage behaviour in organic solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feron, K., E-mail: Krishna.Feron@csiro.au; Fell, C. J.; CSIRO Energy Flagship, Newcastle, NSW 2300

2014-12-07

We present a dynamic Monte Carlo (DMC) study of s-shaped current-voltage (I-V) behaviour in organic solar cells. This anomalous behaviour causes a substantial decrease in fill factor and thus power conversion efficiency. We show that this s-shaped behaviour is induced by charge traps that are located at the electrode interface rather than in the bulk of the active layer, and that the anomaly becomes more pronounced with increasing trap depth or density. Furthermore, the s-shape anomaly is correlated with interface recombination, but not bulk recombination, thus highlighting the importance of controlling the electrode interface. While thermal annealing is known tomore » remove the s-shape anomaly, the reason has been not clear, since these treatments induce multiple simultaneous changes to the organic solar cell structure. The DMC modelling indicates that it is the removal of aluminium clusters at the electrode, which act as charge traps, that removes the anomalous I-V behaviour. Finally, this work shows that the s-shape becomes less pronounced with increasing electron-hole recombination rate; suggesting that efficient organic photovoltaic material systems are more susceptible to these electrode interface effects.« less

Two-Dimensional Cadmium Chloride Nanosheets in Cadmium Telluride Solar Cells.

PubMed

Perkins, Craig L; Beall, Carolyn; Reese, Matthew O; Barnes, Teresa M

2017-06-21

In this study we make use of a liquid nitrogen-based thermomechanical cleavage technique and a surface analysis cluster tool to probe in detail the tin oxide/emitter interface at the front of completed CdTe solar cells. We show that this thermomechanical cleavage occurs within a few angstroms of the SnO 2 /emitter interface. An unexpectedly high concentration of chlorine at this interface, ∼20%, was determined from a calculation that assumed a uniform chlorine distribution. Angle-resolved X-ray photoelectron spectroscopy was used to further probe the structure of the chlorine-containing layer, revealing that both sides of the cleave location are covered by one-third of a unit cell of pure CdCl 2 , a thickness corresponding to about one Cl-Cd-Cl molecular layer. We interpret this result in the context of CdCl 2 being a true layered material similar to transition-metal dichalcogenides. Exposing cleaved surfaces to water shows that this Cl-Cd-Cl trilayer is soluble, raising questions pertinent to cell reliability. Our work provides new and unanticipated details about the structure and chemistry of front surface interfaces and should prove important to improving materials, processes, and reliability of next-generation CdTe-based solar cells.

Preliminary design of a solar central receiver for a site-specific repowering application (Saguaro Power Plant). Volume III. Specifications. Final report, October 1982-September 1983

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weber, E.R.

1983-09-01

This volume on specifications for the Saguaro Power Plant includes the following: subsystem interface definition document; solar collector subsystem specification; receiver specification; thermal energy storage specification; solar steam generator specification; and master control system specification.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, X.; Florinski, V.

We present a new model that couples galactic cosmic-ray (GCR) propagation with magnetic turbulence transport and the MHD background evolution in the heliosphere. The model is applied to the problem of the formation of corotating interaction regions (CIRs) during the last solar minimum from the period between 2007 and 2009. The numerical model simultaneously calculates the large-scale supersonic solar wind properties and its small-scale turbulent content from 0.3 au to the termination shock. Cosmic rays are then transported through the background, and thus computed, with diffusion coefficients derived from the solar wind turbulent properties, using a stochastic Parker approach. Ourmore » results demonstrate that GCR variations depend on the ratio of diffusion coefficients in the fast and slow solar winds. Stream interfaces inside the CIRs always lead to depressions of the GCR intensity. On the other hand, heliospheric current sheet (HCS) crossings do not appreciably affect GCR intensities in the model, which is consistent with the two observations under quiet solar wind conditions. Therefore, variations in diffusion coefficients associated with CIR stream interfaces are more important for GCR propagation than the drift effects of the HCS during a negative solar minimum.« less

Cu(In,Ga)Se2 solar cells with In2S3 buffer layer deposited by thermal evaporation

NASA Astrophysics Data System (ADS)

Kim, SeongYeon; Rana, Tanka R.; Kim, JunHo; Yun, JaeHo

2017-12-01

We report on physical vapor deposition of indium sulfide (In2S3) buffer layers and its application to Cu(In,Ga)Se2 (CIGSe) thin film solar cell. The Indium sulfide buffer layers were evaporated onto CIGSe at various substrate temperatures from room temperature (RT) to 350 °C. The effect of deposition temperature of buffer layers on the solar cell device performance were investigated by analyzing temperature dependent current-voltage ( J- V- T), external quantum efficiency (EQE) and Raman spectroscopy. The fabricated device showed the highest power conversion efficiency of 6.56% at substrate temperature of 250 °C, which is due to the decreased interface recombination. However, the roll-over in J- V curves was observed for solar cell device having buffer deposited at substrate temperature larger than 250 °C. From the measurement results, the interface defect and roll-over related degradation were found to have limitation on the performance of solar cell device.

Solar energy/utility interface - The technical issues

NASA Astrophysics Data System (ADS)

Tabors, R. D.; White, D. C.

1982-01-01

The technical and economic factors affecting an interface between solar/wind power sources and utilities are examined. Photovoltaic, solar thermal, and wind powered systems are subject to stochastic local climatic variations and as such may require full back-up services from utilities, which are then in a position of having reserve generating power and power lines and equipment which are used only part time. The low reliability which has degraded some economies of scale formerly associated with large, centralized power plants, and the lowered rate of the increase in electricity usage is taken to commend the inclusion of power sources with a modular nature such as is available from solar derived electrical generation. Technical issues for maintaining the quality of grid power and also effectively metering purchased and supplied back-up power as part of a homeostatic system of energy control are discussed. It is concluded that economic considerations, rather than technical issues, bear the most difficulty in integrating solar technologies into the utility network.

Printed assemblies of GaAs photoelectrodes with decoupled optical and reactive interfaces for unassisted solar water splitting

NASA Astrophysics Data System (ADS)

Kang, Dongseok; Young, James L.; Lim, Haneol; Klein, Walter E.; Chen, Huandong; Xi, Yuzhou; Gai, Boju; Deutsch, Todd G.; Yoon, Jongseung

2017-03-01

Despite their excellent photophysical properties and record-high solar-to-hydrogen conversion efficiency, the high cost and limited stability of III-V compound semiconductors prohibit their practical application in solar-driven photoelectrochemical water splitting. Here we present a strategy for III-V photocatalysis that can circumvent these difficulties via printed assemblies of epitaxially grown compound semiconductors. A thin film stack of GaAs-based epitaxial materials is released from the growth wafer and printed onto a non-native transparent substrate to form an integrated photocatalytic electrode for solar hydrogen generation. The heterogeneously integrated electrode configuration together with specialized epitaxial design serve to decouple the material interfaces for illumination and electrocatalysis. Subsequently, this allows independent control and optimization of light absorption, carrier transport, charge transfer, and material stability. Using this approach, we construct a series-connected wireless tandem system of GaAs photoelectrodes and demonstrate 13.1% solar-to-hydrogen conversion efficiency of unassisted-mode water splitting.

Maximizing and stabilizing luminescence from halide perovskites with potassium passivation

NASA Astrophysics Data System (ADS)

Abdi-Jalebi, Mojtaba; Andaji-Garmaroudi, Zahra; Cacovich, Stefania; Stavrakas, Camille; Philippe, Bertrand; Richter, Johannes M.; Alsari, Mejd; Booker, Edward P.; Hutter, Eline M.; Pearson, Andrew J.; Lilliu, Samuele; Savenije, Tom J.; Rensmo, Håkan; Divitini, Giorgio; Ducati, Caterina; Friend, Richard H.; Stranks, Samuel D.

2018-03-01

Metal halide perovskites are of great interest for various high-performance optoelectronic applications. The ability to tune the perovskite bandgap continuously by modifying the chemical composition opens up applications for perovskites as coloured emitters, in building-integrated photovoltaics, and as components of tandem photovoltaics to increase the power conversion efficiency. Nevertheless, performance is limited by non-radiative losses, with luminescence yields in state-of-the-art perovskite solar cells still far from 100 per cent under standard solar illumination conditions. Furthermore, in mixed halide perovskite systems designed for continuous bandgap tunability (bandgaps of approximately 1.7 to 1.9 electronvolts), photoinduced ion segregation leads to bandgap instabilities. Here we demonstrate substantial mitigation of both non-radiative losses and photoinduced ion migration in perovskite films and interfaces by decorating the surfaces and grain boundaries with passivating potassium halide layers. We demonstrate external photoluminescence quantum yields of 66 per cent, which translate to internal yields that exceed 95 per cent. The high luminescence yields are achieved while maintaining high mobilities of more than 40 square centimetres per volt per second, providing the elusive combination of both high luminescence and excellent charge transport. When interfaced with electrodes in a solar cell device stack, the external luminescence yield—a quantity that must be maximized to obtain high efficiency—remains as high as 15 per cent, indicating very clean interfaces. We also demonstrate the inhibition of transient photoinduced ion-migration processes across a wide range of mixed halide perovskite bandgaps in materials that exhibit bandgap instabilities when unpassivated. We validate these results in fully operating solar cells. Our work represents an important advance in the construction of tunable metal halide perovskite films and interfaces that can approach the efficiency limits in tandem solar cells, coloured-light-emitting diodes and other optoelectronic applications.

Revealing the beneficial role of K in grain interiors, grain boundaries, and at the buffer interface for highly efficient CuInSe 2 solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muzzillo, Christopher P.; Poplawsky, Jonathan D.; Tong, Ho Ming

K incorporation within grain boundaries, grain interiors, and interfaces has been studied within CuInSe 2 solar cells to better understand the beneficial or detrimental role of K distribution among these regions in chalcopyrite–based solar cells. Solar cells have been fabricated with intentional K introduction into specific regions of the device including the CuInSe 2/CdS interface (CuInSe 2/KInSe 2/CdS) and the grain interiors (Cu 0.93K 0.07InSe 2/CdS). A control CuInSe 2/CdS device was also studied to separate effects of K originating from the soda–lime glass substrate from those of intentionally introduced K. The experiment was designed to understand K effects inmore » Cu(In,Ga)Se 2 solar cells while mitigating complications from multiple elements in the 3 + site. The distribution of all elements within these samples has been directly observed with sub–nm resolution via atom probe tomography. In addition, electron beam–induced current measurements have been performed to correlate the atom probe tomography compositional profiles to the nanoscale carrier collection properties. The experiments show that a large decrease in the Cu/In ratio at the CdS interface can be achieved by forming KInSe 2 at the absorber surface, which drastically improves the device efficiency. The results presented here show a direct link between K concentration, Cu depletion, and In accumulation, such that the Cu/In ratio significantly reduces with K incorporation. In conclusion, the findings help clarify the mechanism behind K–induced efficiency enhancement.« less

Revealing the beneficial role of K in grain interiors, grain boundaries, and at the buffer interface for highly efficient CuInSe 2 solar cells

DOE PAGES

Muzzillo, Christopher P.; Poplawsky, Jonathan D.; Tong, Ho Ming; ...

2018-06-06

K incorporation within grain boundaries, grain interiors, and interfaces has been studied within CuInSe 2 solar cells to better understand the beneficial or detrimental role of K distribution among these regions in chalcopyrite–based solar cells. Solar cells have been fabricated with intentional K introduction into specific regions of the device including the CuInSe 2/CdS interface (CuInSe 2/KInSe 2/CdS) and the grain interiors (Cu 0.93K 0.07InSe 2/CdS). A control CuInSe 2/CdS device was also studied to separate effects of K originating from the soda–lime glass substrate from those of intentionally introduced K. The experiment was designed to understand K effects inmore » Cu(In,Ga)Se 2 solar cells while mitigating complications from multiple elements in the 3 + site. The distribution of all elements within these samples has been directly observed with sub–nm resolution via atom probe tomography. In addition, electron beam–induced current measurements have been performed to correlate the atom probe tomography compositional profiles to the nanoscale carrier collection properties. The experiments show that a large decrease in the Cu/In ratio at the CdS interface can be achieved by forming KInSe 2 at the absorber surface, which drastically improves the device efficiency. The results presented here show a direct link between K concentration, Cu depletion, and In accumulation, such that the Cu/In ratio significantly reduces with K incorporation. In conclusion, the findings help clarify the mechanism behind K–induced efficiency enhancement.« less

Maximizing and stabilizing luminescence from halide perovskites with potassium passivation.

PubMed

Abdi-Jalebi, Mojtaba; Andaji-Garmaroudi, Zahra; Cacovich, Stefania; Stavrakas, Camille; Philippe, Bertrand; Richter, Johannes M; Alsari, Mejd; Booker, Edward P; Hutter, Eline M; Pearson, Andrew J; Lilliu, Samuele; Savenije, Tom J; Rensmo, Håkan; Divitini, Giorgio; Ducati, Caterina; Friend, Richard H; Stranks, Samuel D

2018-03-21

Metal halide perovskites are of great interest for various high-performance optoelectronic applications. The ability to tune the perovskite bandgap continuously by modifying the chemical composition opens up applications for perovskites as coloured emitters, in building-integrated photovoltaics, and as components of tandem photovoltaics to increase the power conversion efficiency. Nevertheless, performance is limited by non-radiative losses, with luminescence yields in state-of-the-art perovskite solar cells still far from 100 per cent under standard solar illumination conditions. Furthermore, in mixed halide perovskite systems designed for continuous bandgap tunability (bandgaps of approximately 1.7 to 1.9 electronvolts), photoinduced ion segregation leads to bandgap instabilities. Here we demonstrate substantial mitigation of both non-radiative losses and photoinduced ion migration in perovskite films and interfaces by decorating the surfaces and grain boundaries with passivating potassium halide layers. We demonstrate external photoluminescence quantum yields of 66 per cent, which translate to internal yields that exceed 95 per cent. The high luminescence yields are achieved while maintaining high mobilities of more than 40 square centimetres per volt per second, providing the elusive combination of both high luminescence and excellent charge transport. When interfaced with electrodes in a solar cell device stack, the external luminescence yield-a quantity that must be maximized to obtain high efficiency-remains as high as 15 per cent, indicating very clean interfaces. We also demonstrate the inhibition of transient photoinduced ion-migration processes across a wide range of mixed halide perovskite bandgaps in materials that exhibit bandgap instabilities when unpassivated. We validate these results in fully operating solar cells. Our work represents an important advance in the construction of tunable metal halide perovskite films and interfaces that can approach the efficiency limits in tandem solar cells, coloured-light-emitting diodes and other optoelectronic applications.

Electron-selective contacts via ultra-thin organic interface dipoles for silicon organic heterojunction solar cells

NASA Astrophysics Data System (ADS)

Reichel, Christian; Würfel, Uli; Winkler, Kristina; Schleiermacher, Hans-Frieder; Kohlstädt, Markus; Unmüssig, Moritz; Messmer, Christoph A.; Hermle, Martin; Glunz, Stefan W.

2018-01-01

In the last years, novel materials for the formation of electron-selective contacts on n-type crystalline silicon (c-Si) heterojunction solar cells were explored as an interfacial layer between the metal electrode and the c-Si wafer. Besides inorganic materials like transition metal oxides or alkali metal fluorides, also interfacial layers based on organic molecules with a permanent dipole moment are promising candidates to improve the contact properties. Here, the dipole effect plays an essential role in the modification of the interface and effective work function of the contact. The amino acids L-histidine, L-tryptophan, L-phenylalanine, glycine, and sarcosine, the nucleobase adenine, and the heterocycle 4-hydroxypyridine were investigated as dipole materials for an electron-selective contact on the back of p- and n-type c-Si with a metal electrode based on aluminum (Al). Furthermore, the effect of an added fluorosurfactant on the resulting contact properties was examined. The performance of n-type c-Si solar cells with a boron diffusion on the front was significantly increased when L-histidine and/or the fluorosurfactant was applied as a full-area back surface field. This improvement was attributed to the modification of the interface and the effective work function of the contact by the dipole material which was corroborated by numerical device simulations. For these solar cells, conversion efficiencies of 17.5% were obtained with open-circuit voltages (Voc) of 625 mV and fill factors of 76.3%, showing the potential of organic interface dipoles for silicon organic heterojunction solar cells due to their simple formation by solution processing and their low thermal budget requirements.

Graphene-enhanced thermal interface materials for heat removal from photovoltaic solar cells

NASA Astrophysics Data System (ADS)

Saadah, M.; Gamalath, D.; Hernandez, E.; Balandin, A. A.

2016-09-01

The increase in the temperature of photovoltaic (PV) solar cells affects negatively their power conversion efficiency and decreases their lifetime. The negative effects are particularly pronounced in concentrator solar cells. Therefore, it is crucial to limit the PV cell temperature by effectively removing the excess heat. Conventional thermal phase change materials (PCMs) and thermal interface materials (TIMs) do not possess the thermal conductivity values sufficient for thermal management of the next generation of PV cells. In this paper, we report the results of investigation of the increased efficiency of PV cells with the use of graphene-enhanced TIMs. Graphene reveals the highest values of the intrinsic thermal conductivity. It was also shown that the thermal conductivity of composites can be increased via utilization of graphene fillers. We prepared TIMs with up to 6% of graphene designed specifically for PV cell application. The solar cells were tested using the solar simulation module. It was found that the drop in the output voltage of the solar panel under two-sun concentrated illumination can be reduced from 19% to 6% when grapheneenhanced TIMs are used. The proposed method can recover up to 75% of the power loss in solar cells.

NASA's Best-Observed X-Class Flare of All Time

NASA Image and Video Library

2014-05-07

This combined image shows the March 29, 2014, X-class flare as seen through the eyes of different observatories. SDO is on the bottom/left, which helps show the position of the flare on the sun. The darker orange square is IRIS data. The red rectangular inset is from Sacramento Peak. The violet spots show the flare's footpoints from RHESSI. -- On March 29, 2014 the sun released an X-class flare. It was observed by NASA's Interface Region Imaging Spectrograph, or IRIS; NASA's Solar Dynamics Observatory, or SDO; NASA's Reuven Ramaty High Energy Solar Spectroscopic Imager, or RHESSI; the Japanese Aerospace Exploration Agency's Hinode; and the National Solar Observatory's Dunn Solar Telescope located at Sacramento Peak in New Mexico. To have a record of such an intense flare from so many observatories is unprecedented. Such research can help scientists better understand what catalyst sets off these large explosions on the sun. Perhaps we may even some day be able to predict their onset and forewarn of the radio blackouts solar flares can cause near Earth - blackouts that can interfere with airplane, ship and military communications. Read more: 1.usa.gov/1kMDQbO Join our Google+ Hangout on May 8 at 2:30pm EST: go.nasa.gov/1mwbBEZ Credit: NASA Goddard NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Multiple-etalon systems for the Advanced Technology Solar Telescope

NASA Technical Reports Server (NTRS)

Gary, G. Allen; Balasubramaniam, K. S.; Sigwarth, Michael

2003-01-01

Multiple etalon systems are discussed that meet the science requirements for a narrow-passband imaging system for the 4-meter National Solar Observatory (NSO)/Advance Technology Solar Telescope (ATST). A multiple etalon system can provide an imaging interferometer that works in four distinct modes: as a spectro-polarimeter, a filter-vector magnetograph, an intermediate-band imager, and broadband high-resolution imager. Specific dual and triple etalon configurations are described that provide a spectrographic passband of 2.0-3.5 micron and reduce parasitic light levels to 10(exp -4) as required for precise polarization measurement, e.g., Zeeman measurements of magnetic sensitive lines. A TESOS-like (Telecentric Etalon SOlar Spectrometer) triple etalon system provides a spectral purity of 10(exp -5). The triple designs have the advantage of reducing the finesse requirement on each etalon; allow the use of more stable blocking filters, and have very high spectral purity. A dual-etalon double-pass (Cavallini-like) system can provide a competing configuration. Such a dual-etalon design can provide high contrast. The selection of the final focal plane instrument will depend on a trade-off between an ideal instrument and practical reality. The trade study will include the number of etalons, their aperture sizes, complexities of the optical train, number of blocking filters, configuration of the electronic control system, computer interfaces, temperature controllers, etalon controllers, and their associated feedback electronics. The heritage of single and multiple etalon systems comes from their use in several observatories, including the Marshall Space Flight Center (MSFC) Solar Observatory, Sacramento Peak Observatory (NSO), and Kiepenheuer-Institut fur Sonnenphysik (KIS, Germany), Mees Solar Observatory (University of Hawaii), and Arcetri Astrophysical Observatory (Italy). The design of the ATST multiple etalon system will benefit from the experience gained at these observatories.

Multiple Etalon Systems for the Advanced Technology Solar Telescope

NASA Technical Reports Server (NTRS)

Gary, G. Allen; Balasubramaniam, K. S.; Sigwarth, Michael; Six, N. Frank (Technical Monitor)

2002-01-01

Multiple etalons systems are discussed that meet the 4-meter NSO/Advance Technology Solar Telescope (http://www.nso.edu/ATST/index.html) instrument and science requirements for a narrow bandpass imaging system. A multiple etalon system can provide an imaging interferometer working in four distinct modes: as a spectro-polarimeter, a filter-vector magnetograph, and a wide-band and broad-band high-resolution imager. Specific dual and triple etalon configurations will be described that provides spectrographic passband of 2.0-3.5nm and reduces parasitic light levels to 1/10000 as required by precise polarization measurement, e.g., Zeeman measurements of magnetic sensitive lines. A TESOS-like triple etalon system provides for spectral purity of 100 thousandths. The triple designs have the advantage of reducing the finesse requirement on each etalon, allowing much more stable blocking filters, and can have very high spectral purity. A dual-etalon double-pass Cavallini-like configuration can provide a competing configuration. This design can provide high contrast with only a double etalon. The selection of the final focal plan instrument will depend on a trade-off of the ideal instrument versus reality, the number of etalons, the aperture of etalons, the number of blocking filters the electronic control system and computer interfaces, the temperature control and controllers for the etalons and the electronics. The use of existing experience should provide significant cost savings. The heritage of use of etalons and multiple etalon systems in solar physics come from a number of observatories, which includes MSFC Solar Observatory (NASA), Sac Peak Observatory (NSO), and Kiepenheuer Institute for Solar Physics (Germany), Mees Solar Observatory (University of Hawaii), and Arcetri Astrophysical Observatory (Italy). The design of the ATST multiple etalon system will reply on the existing experience from these observatories.

Development of the User Interface for AIR-Spec

NASA Astrophysics Data System (ADS)

Cervantes Alcala, E.; Guth, G.; Fedeler, S.; Samra, J.; Cheimets, P.; DeLuca, E.; Golub, L.

2016-12-01

The airborne infrared spectrometer (AIR-Spec) is an imaging spectrometer that will observe the solar corona during the 2017 total solar eclipse. This eclipse will provide a unique opportunity to observe infrared emission lines in the corona. Five spectral lines are of particular interest because they may eventually be used to measure the coronal magnetic field. To avoid infrared absorption from atmospheric water vapor, AIR-Spec will be placed on an NSF Gulfstream aircraft flying above 14.9 km. AIR-Spec must be capable of taking stable images while the plane moves. The instrument includes an image stabilization system, which uses fiber-optic gyroscopes to determine platform rotation, GPS to calculate the ephemeris of the sun, and a voltage-driven mirror to correct the line of sight. An operator monitors a white light image of the eclipse and manually corrects for residual drift. The image stabilization calculation is performed by a programmable automatic controller (PAC), which interfaces with the gyroscopes and mirror controller. The operator interfaces with a separate computer, which acquires images and computes the solar ephemeris. To ensure image stabilization is successful, a human machine interface (HMI) was developed to allow connection between the client and PAC. In order to make control of the instruments user friendly during the short eclipse observation, a graphical user interface (GUI) was also created. The GUI's functionality includes turning image stabilization on and off, allowing the user to input information about the geometric setup, calculating the solar ephemeris, refining estimates of the initial aircraft attitude, and storing data from the PAC on the operator's computer. It also displays time, location, attitude, ephemeris, gyro rates and mirror angles.

Band alignment and charge transfer in rutile-TiO2/CH3NH3PbI3-xClx interfaces.

PubMed

Nemnes, G A; Goehry, C; Mitran, T L; Nicolaev, Adela; Ion, L; Antohe, S; Plugaru, N; Manolescu, A

2015-11-11

Rutile-TiO2/hybrid halide perovskite CH3NH3PbI3-xClx interfaces are investigated by ab initio density functional theory calculations. The role of chlorine in achieving enhanced solar cell power conversion efficiencies is in the focus of recent studies, which point to increased carrier mobilities, reduced recombination rates, a driven morphology evolution of the perovskite layer and improved carrier transport across the interface. As it was recently established that chlorine is preferentially localized in the vicinity of the interface and not in the bulk of the perovskite layer, we analyze the changes introduced in the electronic properties by varying the chlorine concentration near the interface. In particular, we discuss the effects introduced in the electronic band structure and show the role of chlorine in the enhanced electron injection into the rutile-TiO2 layer. Taking into account these implications, we discuss the conditions for optimizing the solar cell efficiency in terms of interfacial chlorine concentration.

Substrate-induced interfacial plasmonics for photovoltaic conversion

PubMed Central

Li, Xinxi; Jia, Chuancheng; Ma, Bangjun; Wang, Wei; Fang, Zheyu; Zhang, Guoqing; Guo, Xuefeng

2015-01-01

Surface plasmon resonance (SPR) is widely used as light trapping schemes in solar cells, because it can concentrate light fields surrounding metal nanostructures and realize light management at the nanoscale. SPR in photovoltaics generally occurs at the metal/dielectric interfaces. A well-defined interface is therefore required to elucidate interfacial SPR processes. Here, we designed a photovoltaic device (PVD) with an atomically flat TiO2 dielectric/dye/graphene/metal nanoparticle (NP) interface for quantitatively studying the SPR enhancement of the photovoltaic conversion. Theoretical and experimental results indicated that the graphene monolayer was transparent to the electromagnetic field. This transparency led to significant substrate-induced plasmonic hybridization at the heterostructure interface. Combined with interparticle plasmonic coupling, the substrate-induced plasmonics concentrated light at the interface and enhanced the photo-excitation of dyes, thus improving the photoelectric conversion. Such a mechanistic understanding of interfacial plasmonic enhancement will further promote the development of efficient plasmon-enhanced solar cells and composite photocatalysts. PMID:26412576

Results from the Science Instrument Definition Team for the Gondola for High Altitude Planetary Science Project

NASA Astrophysics Data System (ADS)

Chanover, Nancy J.; Aslam, Shahid; DiSanti, Michael A.; Hibbitts, Charles A.; Honniball, Casey I.; Paganini, Lucas; Parker, Alex; Skrutskie, Michael F.; Young, Eliot F.

2016-10-01

The Gondola for High Altitude Planetary Science (GHAPS) is an observing asset under development by NASA's Planetary Science Division that will be hosted on stratospheric balloon missions intended for use by the broad planetary science community. GHAPS is being designed in a modular fashion to interface to a suite of instruments as called for by science needs. It will operate at an altitude of 30+ km and will include an optical telescope assembly with a 1-meter aperture and a pointing stability of approximately 1 arcsecond with a flight duration of ~100 days. The spectral grasp of the system is envisaged to include wavelengths spanning the near-ultraviolet to near/mid-infrared (~0.3-5 µm) and possibly to longer wavelengths.The GHAPS Science Instrument Definition Team (SIDT) was convened in May 2016 to define the scope of science investigations, derive the science requirements and instrument concepts for GHAPS, prioritize the instruments according to science priorities that address Planetary Science Decadal Survey questions, and generate a report that is broadly disseminated to the planetary science community. The SIDT examined a wide range of solar system targets and science questions, focusing on unique measurements that could be made from a balloon-borne platform to address high-priority planetary science questions for a fraction of the cost of space missions. The resulting instrument concepts reflect unique capabilities offered by a balloon-borne platform (e.g., observations at spectral regions inaccessible from the ground due to telluric absorption, diffraction-limited imaging, and long duration uninterrupted observations of a target). We discuss example science cases that can be addressed with GHAPS and describe a notional instrument suite that can be used by guest observers to pursue decadal-level science questions.

Semiconducting Single-Walled Carbon Nanotubes in Solar Energy Harvesting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blackburn, Jeffrey L.

Semiconducting single-walled carbon nanotubes (s-SWCNTs) represent a tunable model one-dimensional system with exceptional optical and electronic properties. High-throughput separation and purification strategies have enabled the integration of s-SWCNTs into a number of optoelectronic applications, including photovoltaics (PVs). In this Perspective, we discuss the fundamental underpinnings of two model PV interfaces involving s-SWCNTs. We first discuss s-SWCNT-fullerene heterojunctions where exciton dissociation at the donor-acceptor interface drives solar energy conversion. Next, we discuss charge extraction at the interface between s-SWCNTs and a photoexcited perovskite active layer. In each case, the use of highly enriched semiconducting SWCNT samples enables fundamental insights into themore » thermodynamic and kinetic mechanisms that drive the efficient conversion of solar photons into long-lived separated charges. As a result, these model systems help to establish design rules for next-generation PV devices containing well-defined organic semiconductor layers and help to frame a number of important outstanding questions that can guide future studies.« less

Semiconducting Single-Walled Carbon Nanotubes in Solar Energy Harvesting

DOE PAGES

Blackburn, Jeffrey L.

2017-06-14

Semiconducting single-walled carbon nanotubes (s-SWCNTs) represent a tunable model one-dimensional system with exceptional optical and electronic properties. High-throughput separation and purification strategies have enabled the integration of s-SWCNTs into a number of optoelectronic applications, including photovoltaics (PVs). In this Perspective, we discuss the fundamental underpinnings of two model PV interfaces involving s-SWCNTs. We first discuss s-SWCNT-fullerene heterojunctions where exciton dissociation at the donor-acceptor interface drives solar energy conversion. Next, we discuss charge extraction at the interface between s-SWCNTs and a photoexcited perovskite active layer. In each case, the use of highly enriched semiconducting SWCNT samples enables fundamental insights into themore » thermodynamic and kinetic mechanisms that drive the efficient conversion of solar photons into long-lived separated charges. As a result, these model systems help to establish design rules for next-generation PV devices containing well-defined organic semiconductor layers and help to frame a number of important outstanding questions that can guide future studies.« less

The Virtual Solar Observatory: What Are We Up To Now?

NASA Technical Reports Server (NTRS)

Gurman, J. B.; Hill, F.; Suarez-Sola, F.; Bogart, R.; Amezcua, A.; Martens, P.; Hourcle, J.; Hughitt, K.; Davey, A.

2012-01-01

In the nearly ten years of a functional Virtual Solar Observatory (VSO), http://virtualsolar.org/ we have made it possible to query and access sixty-seven distinct solar data products and several event lists from nine spacecraft and fifteen observatories or observing networks. We have used existing VSO technology, and developed new software, for a distributed network of sites caching and serving SDO HMI and/ or AlA data. We have also developed an application programming interface (API) that has enabled VSO search and data access capabilities in IDL, Python, and Java. We also have quite a bit of work yet to do, including completion of the implementation of access to SDO EVE data, and access to some nineteen other data sets from space- and ground-based observatories. In addition, we have been developing a new graphic user interface that will enable the saving of user interface and search preferences. We solicit advice from the community input prioritizing our task list, and adding to it

Understanding and managing trust at the climate science-policy interface

NASA Astrophysics Data System (ADS)

Lacey, Justine; Howden, Mark; Cvitanovic, Christopher; Colvin, R. M.

2018-01-01

Climate change effects are accelerating, making the need for appropriate actions informed by sound climate knowledge ever more pressing. A strong climate science-policy relationship facilitates the effective integration of climate knowledge into local, national and global policy processes, increases society's responsiveness to a changing climate, and aligns research activity to policy needs. This complex science-policy relationship requires trust between climate science `producers' and `users', but our understanding of trust at this interface remains largely uncritical. To assist climate scientists and policymakers, this Perspective provides insights into how trust develops and operates at the interface of climate science and policy, and examines the extent to which trust can manage — or even create — risk at this interface.

Astrobiobound! Search for Life in the Solar System: Scientists and Engineers Bringing their Challenges to K-12 Students

NASA Astrophysics Data System (ADS)

Klug Boonstra, S. L.; Swann, J.; Manfredi, L.; Zippay, A.; Boonstra, D.

2014-12-01

The Next Generation Science Standards (NGSS) brought many dynamic opportunities and capabilities to the K-12 science classroom - especially with the inclusion of engineering. Using science as a context to help students engage in the engineering practices and engineering disciplinary core ideas is an essential step to students' understanding of how science drives engineering and how engineering enables science. Real world examples and applications are critical for students to see how these disciplines are integrated. Furthermore, the interface of science and engineering raise the level of science understanding, and facilitate higher order thinking skills through relevant experiences. Astrobiobound! is designed for the NGSS (Next Generation Science Standards) and CCSS (Common Core State Standards). Students also practice and build 21st Century Skills. Astrobiobound! help students see how science and systems engineering are integrated to achieve a focused scientific goal. Students engage in the engineering design process to design a space mission which requires them to balance the return of their science data with engineering limitations such as power, mass and budget. Risk factors also play a role during this simulation and adds to the excitement and authenticity. Astrobiobound! presents the authentic first stages of NASA mission design process. This simulation mirrors the NASA process in which the science goals, type of mission, and instruments to return required data to meet mission goals are proposed within mission budget before any of the construction part of engineering can begin. NASA scientists and engineers were consulted in the development of this activity as an authentic simulation of their mission proposal process.

Design principle for efficient charge separation at the donor-acceptor interface for high performance organic solar cell device

NASA Astrophysics Data System (ADS)

Nie, Wanyi; Gupta, Gautam; Crone, Brian; Wang, Hsing-Lin; Mohite, Aditya; MPA-11 Material synthesis and integrated device Team; MPA-chemistry Team

2014-03-01

The performance of donor (D) /acceptor (A) structure based organic electronic devices, such as solar cell, light emitting devices etc., relays on the charge transfer process at the interface dramatically. In organic solar cell, the photo-induced electron-hole pair is tightly bonded and will form a charge transfer (CT) state at the D/A interface after dissociation. There is a large chance for them to recombine through CT state and thus is a major loss that limit the overall performance. Here, we report three different strategies that allow us to completely suppress the exciplex (or charge transfer state) recombination between any D/A system. We observe that the photocurrent increases by 300% and the power conversion efficiency increases by 4-5 times simply by inserting a spacer layer in the form of an a) insulator b) Oliogomer or using a c) heavy atom at the donor-acceptor interface in a P3HT/C60 bilayer device. By using those different functional mono layers, we successfully suppressed the exciplex recombination in evidence of increased photocurrent and open circuit voltage. Moreover, these strategies are applicable universally to any donor-acceptor interface. And we demonstrated such strategies in a bulk-heterojunction device which improved the power conversion efficiency from 3.5% up to 4.6%.

Optical and thermal design of 1.5-m aperture solar UV visible and IR observing telescope for Solar-C mission

NASA Astrophysics Data System (ADS)

Suematsu, Y.; Katsukawa, Y.; Shimizu, T.; Ichimoto, K.; Horiuchi, T.; Matsumoto, Y.; Takeyama, N.

2017-11-01

The next Japanese solar mission, SOLAR-C, which has been envisaged after successful science operation of Hinode (SOLAR-B) mission, is perusing two plans: plan-A and plan-B, and under extensive study from science objectives as well as engineering point of view. The plan-A aims at performing out-of-ecliptic observations for investigating, with helioseismic approach, internal structure and dynamo mechanisms of the Sun. It also explores polar regions where fast solar wind is believed to originate. A baseline orbit for plan-A is a circular orbit of 1 AU distance from the Sun with its inclination at around or greater than 40 degrees. The plan-B aims to study small-scale plasma processes and structures in the solar atmosphere which attract researchers' growing interest, followed by many Hinode discoveries [1], for understanding fully dynamism and magnetic nature of the atmosphere. With plan-B, high-angular-resolution investigation of the entire solar atmosphere (from the photosphere to the corona, including their interface layers, i.e., chromosphere and transition region) is to be performed with enhanced spectroscopic and spectro-polarimetric capability as compared with Hinode, together with enhanced sensitivity towards ultra-violet wavelengths. The orbit of plan-B is either a solar synchronous polar orbit of altitude around 600 km or a geosynchronous orbit to ensure continuous solar observations. After the decision of any one of the two plans, the SOLAR-C will be proposed for launch in mid-2010s. In this paper, we will present a basic design of one of major planned instrumental payload for the plan-B: the Solar Ultra-violet Visible and near IR observing Telescope (hereafter referred to as SUVIT). The basic concept in designing the SUVIT is to utilize as much as possible a heritage of successful telescope of the Solar Optical Telescope (SOT) aboard Hinode [2]. Major differences of SUVIT from SOT are the three times larger aperture of 1.5 m, which enables to collect one order of magnitude more photons than SOT, relatively shorter telescope length of 2.8 m to accommodate a launcher's nosecone size for possible dual-satellite-launch configuration, and much wider observing wavelength from UV (down to 250 nm) through near IR (up to 1100 nm). The large aperture is essentially important to attain scientific goals of the plan-B, especially for accurate diagnostics of the dynamic solar chromosphere as revealed by Hinode, although this make it difficult to design the telescope because of ten times more solar heat load introduced into the telescope. The SUVIT consists of two optically separable components; the telescope assembly (TA) and an accompanying focal plane package equipped with filtergraphs and spectrographs. Opto-mechanical and -thermal performance of the TA is crucial to attain high-quality solar observations and here we present a status of feasible study in its optical and thermal designing for diffraction-limited performance at visible wavelength in a reasonably wide field of view.

Towards tunable and multifunctional interfaces: Multicomponent amorphous alloys and bilayer stacks

NASA Astrophysics Data System (ADS)

Kast, Matthew G.

Controlling the electronic structure and requisite charge transfer at and across interfaces is a grand challenge of materials science. Despite decades of research and numerous successes in the fields microelectronics and photovoltaics much work remains to be done. In many applications, whether they be in microelectronics, photovoltaics or display technology there is a demand for multiple functions at a single interface. Historically, existent materials were either discarded as an option due to known properties or tested with some application based figure of merit in mind. Following this, the quality of the material and/or the preparation of the surface/interface to which the material would be deposited was optimized. As the microelectronics and photovoltaics industries have matured, continued progress (faster, lower power transistors and more efficient, cheaper, abundant solar cells) will require new materials (possibly not previously existent) that are fundamentally better for their application than their highly optimized existent counter parts. The manifestation of this has been seen in the microelectronics field with introduction of hafnium silicates to replace silica (which had previously been monumentally successful) as the gate dielectrics for the most advanced transistors. Continued progress in efficient, cheap, abundant photovoltaics will require similar advances. Advances will be needed in the area of new abundant absorbers that can be deposited cheaply which result in materials with high efficiencies. In addition, selective contacts capable of extracting charge from efficient absorbers with low ohmic losses and low recombination rates will be needed. Presented here are two approaches to the multifunctional interface problem, first the use of amorphous alloys that open up the accessible composition space of thin films significantly and second the use of bilayers that loosen the requirements of a single film at an interface.

Exploring the prominence-corona connection and its expansion into the outer corona using total solar eclipse observations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Habbal, Shadia Rifai; Morgan, Huw; Druckmüller, Miloslav, E-mail: shadia@ifa.hawaii.edu

Prominences constitute the most complex magnetic structures in the solar corona. The ubiquitous presence of their seemingly confined dense and cool plasma in an otherwise million-degree environment remains a puzzle. Using a decade of white light total solar eclipse observations, we show how these images reveal an intricate relationship between prominences and coronal structures both in their immediate vicinity, known as coronal cavities, and in the extended corona out to several solar radii. Observations of suspended prominences and twisted helical structures spanning several solar radii are central to these findings. The different manifestations of the prominence-corona interface that emerge frommore » this study underscore the fundamental role played by prominences in defining and controlling the complex expansion and dynamic behavior of the solar magnetic field in the neighborhood of magnetic polarity reversal regions. This study suggests that the unraveling of prominences and the outward expansion of the helical twisted field lines linked to them could be the solar origin of twisted magnetic flux ropes detected in interplanetary space, and of the mechanism by which the Sun sheds its magnetic helicity. This work also underscores the likely role of the prominence-corona interface as a source of the slow solar wind.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kazmerski, L. L.

'' . . . with robust investments in research and market development, the picture changes dramatically.'' Thus, the realigned U.S. Photovoltaic Industry Roadmap highlights R&D as critical to the tipping point that will make solar photovoltaics (PV) significant in the U.S. energy portfolio--part of a well-designed plan that would bring ''2034 expectations'' to reality by 2020. Technology improvement and introduction depend on key, focused, and pertinent research contributions that range from the most fundamental through the applied. In this paper, we underscore the successes and relevance of our current systems-driven PV R&D programs, which are built on integrated capabilities. Thesemore » capabilities span atomic-level characterization, nanotechnology, new materials design, interface and device engineering, theoretical guidance and modeling, processing, measurements and analysis, and process integration. This presentation identifies and provides examples of critical research tipping points needed to foster now and near technologies (primarily crystalline silicon and thin films) and to introduce coming generations of solar PV that provide options to push us to the next performance levels (devices with ultra-high efficiencies and with ultra-low cost). The serious importance of science and creativity to U.S. PV technology ownership--and the increased focus to accelerate the time from laboratory discovery to industry adoption--are emphasized at this ''tipping point'' for solar PV.« less

Total and Spectral Solar Irradiance Sensor (TSIS) Project Overview

NASA Technical Reports Server (NTRS)

Carlisle, Candace; Wedge, Ronnice; Wu, Dong; Stello, Harry; Robinson, Renee

2015-01-01

The main objective of the Total and Spectral solar Irradiance Sensor (TSIS) is to acquire measurements to determine the direct and indirect effects of solar radiation on climate. TSIS total solar irradiance measurements will extend a 37-year long uninterrupted measurement record of incoming solar radiation, the dominant energy source driving the Earths climate and the most precise indicator of changes in the Suns energy output. TSIS solar spectral irradiance measurements will determine the regions of the Earths multi-layered atmosphere that are affected by solar variability, from which the solar forcing mechanisms causing changes in climate can be quantified. TSIS includes two instruments: the Total Irradiance Monitor (TIM) and the Spectral Irradiance Monitor (SIM), integrated into a single payload. The TSIS TIM and SIM instruments are upgraded versions of the two instruments that are flying on the Solar Radiation and Climate Experiment (SORCE) mission launched in January 2003. TSIS was originally planned for the nadir-pointing National Polar-orbiting Operational Environmental Satellite System (NPOESS) spacecraft. The TSIS instrument passed a Critical Design Review (CDR) for NPOESS in December 2009. In 2010, TSIS was re-planned for the Joint Polar Satellite System (JPSS) Polar Free Flyer (PFF). The TSIS TIM, SIM, and associated electronics were built, tested, and successfully completed pre-ship review as of December 2013.In early 2014, NOAA and NASA agreed to fly TSIS on the International Space Station (ISS). In the FY16 Presidents Budget, NASA assumes responsibility for the TSIS mission on ISS. The TSIS project includes requirements, interface, design, build and test of the TSIS payload, including an updated pointing system, for accommodation on the ISS. It takes advantage of the prior development of the TSIS sensors and electronics. The International Space Station (ISS) program contributions include launch services and robotic installation of the TSIS payload onto an ISS Express Logistics Carrier, mission operations, and communications. Total and Spectral solar irradiance data products will be produced, calibrated, and made publically available through the Goddard Earth Science Data and Information Services Center (GES DISC).The NASA GSFC TSIS project at GSFC is responsible for project management, system engineering, safety and mission assurance, and engineering oversight for the TSIS payload. The TSIS project has contracted with the University of Colorado Laboratory for Atmospheric and Space Physics (LASP) for the design, development and testing of TSIS, support for ISS integration, science operations of the TSIS instrument, data processing, data evaluation and delivery to the GES DISC. TSIS will be delivered to Kennedy Space Center for integration in 2017, with launch and installation onto ISS planned for late 2017-early 2018. After a 90-day check-out period, NASA plans five years of TSIS operations.

Expanded Owens Valley Solar Array Science and Data Products

NASA Astrophysics Data System (ADS)

Gary, Dale E.; Hurford, G. J.; Nita, G. M.; Fleishman, G. D.; McTiernan, J. M.

2010-05-01

The Owens Valley Solar Array (OVSA) has been funded for major expansion, to create a university-based facility serving a broad scientific community, to keep the U.S. competitive in the field of solar radio physics. The project, funded by the National Science Foundation through the MRI-Recovery and Reinvestment program, will result in a world-class facility for scientific research at microwave radio frequencies (1-18 GHz) in solar and space weather physics. The project also includes an exciting program of targeted astronomical science. The solar science to be addressed focuses on the magnetic structure of the solar corona, on transient phenomena resulting from magnetic interactions, including the sudden release of energy and subsequent particle acceleration and heating, and on space weather phenomena. The project will support the scientific community by providing open data access and software tools for analysis of the data, to exploit synergies with on-going solar research in other wavelength bands. The New Jersey Institute of Technology (NJIT) will upgrade OVSA from its current complement of 7 antennas to a total of 15 by adding 8 new antennas, and will reinvest in the existing infrastructure by replacing the existing control systems, signal transmission, and signal processing with modern, far more capable and reliable systems based on new technology developed for the Frequency Agile Solar Radiotelescope (FASR). The project will be completed in time to provide solar-dedicated observations during the upcoming solar maximum in 2013 and beyond. We will detail the new science addressed by the expanded array, and provide an overview of the expected data products.

Interface Optoelectronics Engineering for Mechanically Stacked Tandem Solar Cells Based on Perovskite and Silicon.

PubMed

Kanda, Hiroyuki; Uzum, Abdullah; Nishino, Hitoshi; Umeyama, Tomokazu; Imahori, Hiroshi; Ishikawa, Yasuaki; Uraoka, Yukiharu; Ito, Seigo

2016-12-14

Engineering of photonics for antireflection and electronics for extraction of the hole using 2.5 nm of a thin Au layer have been performed for two- and four-terminal tandem solar cells using CH 3 NH 3 PbI 3 perovskite (top cell) and p-type single crystal silicon (c-Si) (bottom cell) by mechanically stacking. Highly transparent connection multilayers of evaporated-Au and sputtered-ITO films were fabricated at the interface to be a point-contact tunneling junction between the rough perovskite and flat silicon solar cells. The mechanically stacked tandem solar cell with an optimized tunneling junction structure was ⟨perovskite for the top cell/Au (2.5 nm)/ITO (154 nm) stacked-on ITO (108 nm)/c-Si for the bottom cell⟩. It was confirmed the best efficiency of 13.7% and 14.4% as two- and four-terminal devices, respectively.

Solar thermal repowering systems integration. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dubberly, L. J.; Gormely, J. E.; McKenzie, A. W.

1979-08-01

This report is a solar repowering integration analysis which defines the balance-of-plant characteristics and costs associated with the solar thermal repowering of existing gas/oil-fired electric generating plants. Solar repowering interface requirements for water/steam and salt or sodium-cooled central receivers are defined for unit sizes ranging from 50 MWe non-reheat to 350 MWe reheat. Finally balance-of-plant cost estimates are presented for each of six combinations of plant type, receiver type and percent solar repowering.

KSC-2013-2627

NASA Image and Video Library

2013-06-10

VANDENBERG AFB – Detail of the Orbital Sciences Pegasus XL rocket that will lift NASA's IRIS solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch from Vandenberg June 26. IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Tony Vauclin

KSC-2013-2620

NASA Image and Video Library

2013-06-10

VANDENBERG AFB – Detail of the Orbital Sciences Pegasus XL rocket that will lift NASA's IRIS solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch from Vandenberg June 26. IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Tony Vauclin

KSC-2013-2625

NASA Image and Video Library

2013-06-10

VANDENBERG AFB – Detail of the Orbital Sciences Pegasus XL rocket that will lift NASA's IRIS solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch from Vandenberg June 26. IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Tony Vauclin

Efficient inverted bulk-heterojunction polymer solar cells with self-assembled monolayer modified zinc oxide.

PubMed

Kim, Wook Hyun; Lyu, Hong-Kun; Han, Yoon Soo; Woo, Sungho

2013-10-01

The performance of poly(3-hexylthiophen) (P3HT) and [6, 6]phenyl C61 butyric acid methyl ester ([60]PCBM)-based inverted bulk-heterojunction (BHJ) polymer solar cells (PSCs) is enhanced by the modification of zinc oxide (ZnO)/BHJ interface with carboxylic-acid-functionalized self-assembled monolayers (SAMs). Under simulated solar illumination of AM 1.5 (100 mW/cm2), the inverted devices fabricated with SAM-modified ZnO achieved an enhanced power conversion efficiency (PCE) of 3.34% due to the increased fill factor and photocurrent density as compared to unmodified cells with PCE of 2.60%. This result provides an efficient method for interface engineering in inverted BHJ PSCs.

Multiple Discipline science assessment. [considering astronomy, astrophysics, cosmology, gravitation and geophysics when planning planetary missions

NASA Technical Reports Server (NTRS)

Wells, W. C.

1978-01-01

Various science disciplines were examined to determine where and when it is appropriate to include their objectives in the planning of planetary missions. The disciplines considered are solar astronomy, stellar and galactic astronomy, solar physics, cosmology and gravitational physics, the geosciences and the applied sciences. For each discipline, science objectives are identified which could provide a multiple discipline opportunity utilizing either a single spacecraft or two spacecraft delivered by a single launch vehicle. Opportunities using a common engineering system are also considered. The most promising opportunities identified include observations of solar images and relativistic effects using the Mercury orbiter; collection of samples exposed to solar radiation using the Mars surface sample return; studies of interstellar neutral H and He, magnetic fields, cosmic rays, and solar physics during Pluto or Neptune flybys; using the Mars orbiter to obtain solar images from 0.2 AU synchronous or from 90 deg orbit; and the study of the structure and composition of the atmosphere using atmospheric probes and remotely piloted vehicles.

Receivers

NASA Technical Reports Server (NTRS)

Donnelly, H.

1983-01-01

Before discussing Deep Space Network receivers, a brief description of the functions of receivers and how they interface with other elements of the Network is presented. Different types of receivers are used in the Network for various purposes. The principal receiver type is used for telemetry and tracking. This receiver provides the capability, with other elements of the Network, to track the space probe utilizing Doppler and range measurements, and to receive telemetry, including both scientific data from the onboard experiments and engineering data pertaining to the health of the probe. Another type of receiver is used for radio science applications. This receiver measures phase perturbations on the carrier signal to obtain information on the composition of solar and planetary atmospheres and interplanetary space. A third type of receiver utilizes very long baseline interferometry (VLBI) techniques for both radio science and spacecraft navigation data. Only the telemetry receiver is described in detail in this document. The integration of the Receiver-Exciter subsystem with other portions of the Deep Space Network is described.

Solar Probe Plus: A NASA Mission to Touch the Sun

NASA Astrophysics Data System (ADS)

Fox, N. J.; Bale, S. D.; Decker, R. B.; Howard, R.; Kasper, J. C.; McComas, D. J.; Szabo, A.; Velli, M. M.

2013-12-01

Solar Probe Plus (SPP), currently in Phase B, will be the first mission to fly into the low solar corona, revealing how the corona is heated and the solar wind is accelerated, solving two fundamental mysteries that have been top priority science goals since such a mission was first proposed in 1958. The scale and concept of such a mission has been revised at intervals since that time, yet the core has always been a close encounter with the Sun. The primary science goal of the Solar Probe Plus mission is to determine the structure and dynamics of the Sun's coronal magnetic field, understand how the solar corona and wind are heated and accelerated, and determine what mechanisms accelerate and transport energetic particles. The SPP mission will achieve this by identifying and quantifying the basic plasma physical processes at the heart of the Heliosphere. SPP uses an innovative mission design, significant technology development and a risk-reducing engineering development to meet the SPP science objectives: 1) Trace the flow of energy that heats and accelerates the solar corona and solar wind; 2) Determine the structure and dynamics of the plasma and magnetic fields at the sources of the solar wind; and 3) Explore mechanisms that accelerate and transport energetic particles. In this poster, we present Solar Probe Plus and examine how the mission will address the science questions that have remained unanswered for over 5 decades.

Report on the solar physics-plasma physics workshop

NASA Technical Reports Server (NTRS)

Sturrock, P. A.; Baum, P. J.; Beckers, J. M.; Newman, C. E.; Priest, E. R.; Rosenberg, H.; Smith, D. F.; Wentzel, D. G.

1976-01-01

The paper summarizes discussions held between solar physicists and plasma physicists on the interface between solar and plasma physics, with emphasis placed on the question of what laboratory experiments, or computer experiments, could be pursued to test proposed mechanisms involved in solar phenomena. Major areas discussed include nonthermal plasma on the sun, spectroscopic data needed in solar plasma diagnostics, types of magnetic field structures in the sun's atmosphere, the possibility of MHD phenomena involved in solar eruptive phenomena, the role of non-MHD instabilities in energy release in solar flares, particle acceleration in solar flares, shock waves in the sun's atmosphere, and mechanisms of radio emission from the sun.

Inverters for interfacing of solar cells with the power grid

NASA Astrophysics Data System (ADS)

Karamanzanis, G. N.; Jackson, R. D.

In this work, based on a research course in the Engineering Dep. Cambridge University, some non-classical inverter circuits are studied. They can be used for interfacing solar cells with the power grid at low voltage (230V) and at low power level. They are based on d.c. choppers which have a fast switching transistor. Their theoretical efficiency is 100 percent and they provide a satisfactory output current waveform in phase to the a.c. line voltage. The problems of control are also studied using a suitable mathematical model.

Tailoring the interface using thiophene small molecules in TiO2/P3HT hybrid solar cells.

PubMed

Freitas, Flavio S; Clifford, John N; Palomares, Emilio; Nogueira, Ana F

2012-09-14

In this paper we focus on the effect of carboxylated thiophene small molecules as interface modifiers in TiO(2)/P3HT hybrid solar cells. Our results show that small differences in the chemical structure of these molecules, for example, the presence of the -CH(2)- group in the 2-thiopheneacetic acid (TAA), can greatly increase the TiO(2) surface wettability, improving the TiO(2)/polymer contact. This effect is important to enhance exciton splitting and charge separation.

Emitter/absorber interface of CdTe solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Tao, E-mail: tsong241@gmail.com; Sites, James R.; Kanevce, Ana

The performance of CdTe solar cells can be very sensitive to the emitter/absorber interface, especially for high-efficiency cells with high bulk lifetime. Performance losses from acceptor-type interface defects can be significant when interface defect states are located near mid-gap energies. Numerical simulations show that the emitter/absorber band alignment, the emitter doping and thickness, and the defect properties of the interface (i.e., defect density, defect type, and defect energy) can all play significant roles in the interface recombination. In particular, a type I heterojunction with small conduction-band offset (0.1 eV ≤ ΔE{sub C} ≤ 0.3 eV) can help maintain good cell efficiency in spite of high interfacemore » defect density, much like with Cu(In,Ga)Se{sub 2} (CIGS) cells. The basic principle is that positive ΔE{sub C}, often referred to as a “spike,” creates an absorber inversion and hence a large hole barrier adjacent to the interface. As a result, the electron-hole recombination is suppressed due to an insufficient hole supply at the interface. A large spike (ΔE{sub C} ≥ 0.4 eV), however, can impede electron transport and lead to a reduction of photocurrent and fill-factor. In contrast to the spike, a “cliff” (ΔE{sub C} < 0 eV) allows high hole concentration in the vicinity of the interface, which will assist interface recombination and result in a reduced open-circuit voltage. Another way to mitigate performance losses due to interface defects is to use a thin and highly doped emitter, which can invert the absorber and form a large hole barrier at the interface. CdS is the most common emitter material used in CdTe solar cells, but the CdS/CdTe interface is in the cliff category and is not favorable from the band-offset perspective. The ΔE{sub C} of other n-type emitter choices, such as (Mg,Zn)O, Cd(S,O), or (Cd,Mg)Te, can be tuned by varying the elemental ratio for an optimal positive value of ΔE{sub C}. These materials are predicted to yield higher voltages and would therefore be better candidates for the CdTe-cell emitter.« less

The National Solar Observatory Digital Library - a resource for space weather studies

NASA Astrophysics Data System (ADS)

Hill, F.; Erdwurm, W.; Branston, D.; McGraw, R.

2000-09-01

We describe the National Solar Observatory Digital Library (NSODL), consisting of 200GB of on-line archived solar data, a RDBMS search engine, and an Internet HTML-form user interface. The NSODL is open to all users and provides simple access to solar physics data of basic importance for space weather research and forecasting, heliospheric research, and education. The NSODL can be accessed at the URL www.nso.noao.edu/diglib.

The Projects for Onboard Autonomy (PROBA2) Science Centre: Sun Watcher Using APS Detectors and Image Processing (SWAP) and Large-Yield Radiometer (LYRA) Science Operations and Data Products

NASA Astrophysics Data System (ADS)

Zender, J.; Berghmans, D.; Bloomfield, D. S.; Cabanas Parada, C.; Dammasch, I.; De Groof, A.; D'Huys, E.; Dominique, M.; Gallagher, P.; Giordanengo, B.; Higgins, P. A.; Hochedez, J.-F.; Yalim, M. S.; Nicula, B.; Pylyser, E.; Sanchez-Duarte, L.; Schwehm, G.; Seaton, D. B.; Stanger, A.; Stegen, K.; Willems, S.

2013-08-01

The PROBA2 Science Centre (P2SC) is a small-scale science operations centre supporting the Sun observation instruments onboard PROBA2: the EUV imager Sun Watcher using APS detectors and image Processing (SWAP) and Large-Yield Radiometer (LYRA). PROBA2 is one of ESA's small, low-cost Projects for Onboard Autonomy (PROBA) and part of ESA's In-Orbit Technology Demonstration Programme. The P2SC is hosted at the Royal Observatory of Belgium, co-located with both Principal Investigator teams. The P2SC tasks cover science planning, instrument commanding, instrument monitoring, data processing, support of outreach activities, and distribution of science data products. PROBA missions aim for a high degree of autonomy at mission and system level, including the science operations centre. The autonomy and flexibility of the P2SC is reached by a set of web-based interfaces allowing the operators as well as the instrument teams to monitor quasi-continuously the status of the operations, allowing a quick reaction to solar events. In addition, several new concepts are implemented at instrument, spacecraft, and ground-segment levels allowing a high degree of flexibility in the operations of the instruments. This article explains the key concepts of the P2SC, emphasising the automation and the flexibility achieved in the commanding as well as the data-processing chain.

Materials, device, and interface engineering to improve polymer-based solar cells

NASA Astrophysics Data System (ADS)

Hau, Steven Kin

The continued depletion of fossil fuel resources has lead to the rise in energy production costs which has lead to the search for an economically viable alternative energy source. One alternative of particular interest is solar energy. A promising alternative to inorganic materials is organic semiconductor polymer solar cells due to their advantages of being cheaper, light weight, flexible and made into large areas by roll-to-roll processing. In this dissertation, an integrated approach is taken to improve the overall performance of polymer-based solar cells by the development of new polymer materials, device architectures, and interface engineering of the contacts between layers. First, a new class of metallated conjugated polymers is explored as potential solar cell materials. Systematic modifications to the molecular units on the main chain of amorphous metallated Pt-polymers show a correlation that improving charge carrier mobility also improves solar cell performance leading to mobilities as high as 1 x 10-2 cm2/V·s and efficiencies as high as 4.1%. Second, an inverted device architecture using a more air stable electrode (Ag) is demonstrated to improve the ambient stability of unencapsulated P3HT:PCBM devices showing over 80% efficiency retention after 40 days of exposure. To further demonstrate the potential for roll-to-roll processing of polymer solar cells, solution processed Ag-nanoparticles were used to replace the vacuum deposited Ag anode electrode for inverted solar cells showing efficiencies as high as 3%. In addition, solution processed polymer based electrodes were demonstrated as a replacement to the expensive and brittle indium tin oxide showing efficiencies of 3% on flexible substrate solar cells. Third, interface engineering of the n-type (high temperature sol-gel processed TiO2 or ZnO, low temperature processed ZnO nanoparticles) electron selective metal oxide contacts in inverted solar cells with self-assembled monolayers (SAM) show improved device performance. Modifying the n-type layer in inverted cells with C60-SAMs containing different anchoring groups leads to an improvement in photocurrent density and fill factor leading to efficiencies as high as 4.9%.

Telescience Testbed Program: A study of software for SIRTF instrument control

NASA Technical Reports Server (NTRS)

Young, Erick T.

1992-01-01

As a continued element in the Telescience Testbed Program (TTP), the University of Arizona Steward Observatory and the Electrical and Computer Engineering Department (ECE) jointly developed a testbed to evaluate the Operations and Science Instrument System (OASIS) software package for remote control of an instrument for the Space Infrared Telescope Facility (SIRTF). SIRTF is a cryogenically-cooled telescope with three focal plane instruments that will be the infrared element of NASA's Great Observatory series. The anticipated launch date for SIRTF is currently 2001. Because of the complexity of the SIRTF mission, it was not expected that the OASIS package would be suitable for instrument control in the flight situation, however, its possible use as a common interface during the early development and ground test phases of the project was considered. The OASIS package, developed at the University of Colorado for control of the Solar Mesosphere Explorer (SME) satellite, serves as an interface between the operator and the remote instrument which is connected via a network. OASIS provides a rudimentary windowing system as well as support for standard spacecraft communications protocols. The experiment performed all of the functions required of the MIPS simulation program. Remote control of the instrument was demonstrated but found to be inappropriate for SIRTF at this time for the following reasons: (1) programming interface is too difficult; (2) significant computer resources were required to run OASIS; (3) the communications interface is too complicated; (4) response time was slow; and (5) quicklook of image data was not possible.

Two-Dimensional Cadmium Chloride Nanosheets in Cadmium Telluride Solar Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perkins, Craig L.; Beall, Carolyn; Reese, Matthew O.

In this paper we make use of a liquid nitrogen-based thermomechanical cleavage technique and a surface analysis cluster tool to probe in detail the tin oxide/emitter interface at the front of completed CdTe solar cells. We show that this thermomechanical cleavage occurs within a few angstroms of the SnO 2/emitter interface. An unexpectedly high concentration of chlorine at this interface, ~20%, was determined from a calculation that assumed a uniform chlorine distribution. Angle-resolved X-ray photoelectron spectroscopy was used to further probe the structure of the chlorine-containing layer, revealing that both sides of the cleave location are covered by one-third ofmore » a unit cell of pure CdCl 2, a thickness corresponding to about one Cl-Cd-Cl molecular layer. We interpret this result in the context of CdCl 2 being a true layered material similar to transition-metal dichalcogenides. Exposing cleaved surfaces to water shows that this Cl-Cd-Cl trilayer is soluble, raising questions pertinent to cell reliability. Our work provides new and unanticipated details about the structure and chemistry of front surface interfaces and should prove important to improving materials, processes, and reliability of next-generation CdTe-based solar cells.« less

Two-Dimensional Cadmium Chloride Nanosheets in Cadmium Telluride Solar Cells

DOE PAGES

Perkins, Craig L.; Beall, Carolyn; Reese, Matthew O.; ...

2017-05-12

In this paper we make use of a liquid nitrogen-based thermomechanical cleavage technique and a surface analysis cluster tool to probe in detail the tin oxide/emitter interface at the front of completed CdTe solar cells. We show that this thermomechanical cleavage occurs within a few angstroms of the SnO 2/emitter interface. An unexpectedly high concentration of chlorine at this interface, ~20%, was determined from a calculation that assumed a uniform chlorine distribution. Angle-resolved X-ray photoelectron spectroscopy was used to further probe the structure of the chlorine-containing layer, revealing that both sides of the cleave location are covered by one-third ofmore » a unit cell of pure CdCl 2, a thickness corresponding to about one Cl-Cd-Cl molecular layer. We interpret this result in the context of CdCl 2 being a true layered material similar to transition-metal dichalcogenides. Exposing cleaved surfaces to water shows that this Cl-Cd-Cl trilayer is soluble, raising questions pertinent to cell reliability. Our work provides new and unanticipated details about the structure and chemistry of front surface interfaces and should prove important to improving materials, processes, and reliability of next-generation CdTe-based solar cells.« less

Redefining Scientist-Educator Partnerships: Science in Service at Stanford

NASA Astrophysics Data System (ADS)

Beck, K.

2005-05-01

The Stanford Solar Observatories Group and Haas Center for Public Service have created an innovative model for scientist-educator partnerships in which science students are trained and mentored by public service education professionals to create outreach events for local communities. The program, Science in Service, is part of the EPO plan for the Solar Group's participation in NASA's Solar Dynamics Observatory mission. Based on the principles of service learning, the Science in Service Program mentors college science students in best practices for communicating science and engages these students in public service projects that center on teaching solar science. The program goals are to - Enhance and expand the learning experiences that pre-college students, from underserved and underrepresented groups in particular, have in science and technology. - Promote leadership in community service in the area of science and engineering among the next generation of scientists and engineers, today's undergraduate students. - Encourage science and engineering faculty to think creatively about their outreach requirements and to create a community of faculty committed to quality outreach programs. This talk will describe the unique advantages and challenges of a research-public service partnership, explain the structure of Stanford's Science in Service Program, and present the experiences of the undergraduates and the outreach communities that have been involved in the program.

Graphics interfaces and numerical simulations: Mexican Virtual Solar Observatory

NASA Astrophysics Data System (ADS)

Hernández, L.; González, A.; Salas, G.; Santillán, A.

2007-08-01

Preliminary results associated to the computational development and creation of the Mexican Virtual Solar Observatory (MVSO) are presented. Basically, the MVSO prototype consists of two parts: the first, related to observations that have been made during the past ten years at the Solar Observation Station (EOS) and at the Carl Sagan Observatory (OCS) of the Universidad de Sonora in Mexico. The second part is associated to the creation and manipulation of a database produced by numerical simulations related to solar phenomena, we are using the MHD ZEUS-3D code. The development of this prototype was made using mysql, apache, java and VSO 1.2. based GNU and `open source philosophy'. A graphic user interface (GUI) was created in order to make web-based, remote numerical simulations. For this purpose, Mono was used, because it is provides the necessary software to develop and run .NET client and server applications on Linux. Although this project is still under development, we hope to have access, by means of this portal, to other virtual solar observatories and to be able to count on a database created through numerical simulations or, given the case, perform simulations associated to solar phenomena.

Accessing Solar Irradiance Data Products From the LASP Interactive Solar IRradiance Datacenter (LISIRD)

NASA Astrophysics Data System (ADS)

Ware Dewolfe, A.; Wilson, A.; Lindholm, D. M.; Pankratz, C. K.; Snow, M.; Woods, T. N.

2009-12-01

The Laboratory for Atmospheric and Space Physics (LASP) is enhancing the LASP Interactive Solar IRradiance Datacenter (LISIRD) to provide access to a comprehensive set of solar spectral irradiance measurements. LISIRD has recently been updated to serve many new datasets and models, including sunspot index, photometric sunspot index, Lyman-alpha, and magnesium-II core-to-wing ratio. A new user interface emphasizes web-based interactive visualizations, allowing users to explore and compare this data before downloading it for analysis. The data provided covers a wavelength range from soft X-ray (XUV) at 0.1 nm up to the near infrared (NIR) at 2400 nm, as well as wavelength-independent Total Solar Irradiance (TSI). Combined data from the SORCE, TIMED-SEE, UARS-SOLSTICE, and SME instruments provide almost continuous coverage from 1981 to the present, while Hydrogen Lyman-alpha (121.6 nm) measurements / models date from 1947 to the present. This poster provides an overview of the LISIRD system, summarizes the data sets currently available, describes future plans and capabilities, and provides details on how to access solar irradiance data through LISIRD interfaces at http://lasp.colorado.edu/lisird/.

Solar Irradiance Data Products at the LASP Interactive Solar IRradiance Datacenter (LISIRD)

NASA Astrophysics Data System (ADS)

Ware Dewolfe, A.; Wilson, A.; Lindholm, D. M.; Pankratz, C. K.; Snow, M. A.; Woods, T. N.

2010-12-01

The Laboratory for Atmospheric and Space Physics (LASP) has developed the LASP Interactive Solar IRradiance Datacenter (LISIRD) to provide access to a comprehensive set of solar irradiance measurements. LISIRD has recently been updated to serve many new datasets and models, including data from SORCE, UARS-SOLSTICE, SME, and TIMED-SEE, and model data from the Flare Irradiance Spectral Model (FISM). The user interface emphasizes web-based interactive visualizations, allowing users to explore and compare this data before downloading it for analysis. The data provided covers a wavelength range from soft X-ray (XUV) at 0.1 nm up to the near infrared (NIR) at 2400 nm, as well as wavelength-independent Total Solar Irradiance (TSI). Combined data from the SORCE, TIMED-SEE, UARS-SOLSTICE, and SME instruments provide continuous coverage from 1981 to the present, while Lyman-alpha measurements, FISM daily data, and TSI models date from the 1940s to the present. LISIRD will also host Glory TSI data as part of the SORCE data system. This poster provides an overview of the LISIRD system, summarizes the data sets currently available, describes future plans and capabilities, and provides details on how to access solar irradiance data through LISIRD’s interfaces.

Tuning Transpiration by Interfacial Solar Absorber-Leaf Engineering.

PubMed

Zhuang, Shendong; Zhou, Lin; Xu, Weichao; Xu, Ning; Hu, Xiaozhen; Li, Xiuqiang; Lv, Guangxin; Zheng, Qinghui; Zhu, Shining; Wang, Zhenlin; Zhu, Jia

2018-02-01

Plant transpiration, a process of water movement through a plant and its evaporation from aerial parts especially leaves, consumes a large component of the total continental precipitation (≈48%) and significantly influences global water distribution and climate. To date, various chemical and/or biological explorations have been made to tune the transpiration but with uncertain environmental risks. In recent years, interfacial solar steam/vapor generation is attracting a lot of attention for achieving high energy transfer efficiency. Various optical and thermal designs at the solar absorber-water interface for potential applications in water purification, seawater desalination, and power generation appear. In this work, the concept of interfacial solar vapor generation is extended to tunable plant transpiration by showing for the first time that the transpiration efficiency can also be enhanced or suppressed through engineering the solar absorber-leaf interface. By tuning the solar absorption of membrane in direct touch with green leaf, surface temperature of green leaf will change accordingly because of photothermal effect, thus the transpiration efficiency as well as temperature and relative humidity in the surrounding environment will be tuned. This tunable transpiration by interfacial absorber-leaf engineering can open an alternative avenue to regulate local atmospheric temperature, humidity, and eventually hydrologic cycle.

Teaching and sharing about the Sun in the United States and with Spanish language resources

NASA Astrophysics Data System (ADS)

Peticolas, L. M.; Craig, N.; Hawkins, I.; Walker, C.

2007-05-01

The United States has many different scientific agencies that fund research on solar science, including the National Aeronautics and Space Agency (NASA) and the National Science Foundation (NSF). Because there is a large population of Spanish-speaking people in the US, some of the resources developed by the education components of research projects take into account broader cultural perspectives on science and are developed in Spanish. We will describe the education and outreach programs of three solar programs funded by NASA and NSF, the Solar TErrestrial RElations Observatory (STEREO) program, the "We Are One Under the Sun" Program, and the National Optical Astronomy Observatory (NOAO) education program. The STEREO program aims to teach about the Sun through different venues including teacher workshops and courses, teacher materials, turning solar data from STEREO into sound, working with museums, and creating solar posters, CDs, DVDs, and lenticulars. The "We are One Under the Sun" program focuses on Native Americans and Hispanics of Native heritage. It works by merging culture, ancient observatories, and the latest NASA solar science to engage children, youth, and the general public in science and technology through solar traditions in their own indigenous culture. The NOAO Educational Outreach Program was established to make the science and scientists of NOAO more accessible to the K-12 and college-level communities. We will focus on the NOAO solar projects and Spanish-Language Astronomy Materials Educational Center program, which provides multiple types of Spanish- language materials for teachers. These programs have had different levels of outreach in Spanish-speaking countries, namely Mexico (STEREO and "We are One Under the Sun") and Chile (NOAO). We will describe these efforts and give links to the Spanish and English resources available to learn and teach about the Sun.

Fundamentals and applications of solar energy. Part 2

NASA Astrophysics Data System (ADS)

Faraq, I. H.; Melsheimer, S. S.

Applications of techniques of chemical engineering to the development of materials, production methods, and performance optimization and evaluation of solar energy systems are discussed. Solar thermal storage systems using phase change materials, liquid phase Diels-Alder reactions, aquifers, and hydrocarbon oil were examined. Solar electric systems were explored in terms of a chlorophyll solar cell, the nonequilibrium electric field effects developed at photoelectrode/electrolyte interfaces, and designs for commercial scale processing of solar cells using continuous thin-film coating production methods. Solar coal gasification processes were considered, along with multilayer absorber coatings for solar concentrator receivers, solar thermal industrial applications, the kinetics of anaerobic digestion of crop residues to produce methane, and a procedure for developing a computer simulation of a solar cooling system.

Exploring Novel Spintronic Responses from Advanced Functional Organic Materials

DTIC Science & Technology

2015-11-12

March 20-22, 2014 (8) Interface enhanced photovoltaic and Seebeck effects in organic solar cells and thermoelectric devices DISTRIBUTION A...on thermoelectric effects by using polymer/metal interface-controllable thermal and electric conductions. The project explored a new strategy by using...following major breakthroughs on molecular metamaterials by using spin radicals and on thermoelectric effects by using polymer/metal interface

One-Year stable perovskite solar cells by 2D/3D interface engineering

NASA Astrophysics Data System (ADS)

Grancini, G.; Roldán-Carmona, C.; Zimmermann, I.; Mosconi, E.; Lee, X.; Martineau, D.; Narbey, S.; Oswald, F.; de Angelis, F.; Graetzel, M.; Nazeeruddin, Mohammad Khaja

2017-06-01

Despite the impressive photovoltaic performances with power conversion efficiency beyond 22%, perovskite solar cells are poorly stable under operation, failing by far the market requirements. Various technological approaches have been proposed to overcome the instability problem, which, while delivering appreciable incremental improvements, are still far from a market-proof solution. Here we show one-year stable perovskite devices by engineering an ultra-stable 2D/3D (HOOC(CH2)4NH3)2PbI4/CH3NH3PbI3 perovskite junction. The 2D/3D forms an exceptional gradually-organized multi-dimensional interface that yields up to 12.9% efficiency in a carbon-based architecture, and 14.6% in standard mesoporous solar cells. To demonstrate the up-scale potential of our technology, we fabricate 10 × 10 cm2 solar modules by a fully printable industrial-scale process, delivering 11.2% efficiency stable for >10,000 h with zero loss in performances measured under controlled standard conditions. This innovative stable and low-cost architecture will enable the timely commercialization of perovskite solar cells.

One-Year stable perovskite solar cells by 2D/3D interface engineering

PubMed Central

Grancini, G.; Roldán-Carmona, C.; Zimmermann, I.; Mosconi, E.; Lee, X.; Martineau, D.; Narbey, S.; Oswald, F.; De Angelis, F.; Graetzel, M.; Nazeeruddin, Mohammad Khaja

2017-01-01

Despite the impressive photovoltaic performances with power conversion efficiency beyond 22%, perovskite solar cells are poorly stable under operation, failing by far the market requirements. Various technological approaches have been proposed to overcome the instability problem, which, while delivering appreciable incremental improvements, are still far from a market-proof solution. Here we show one-year stable perovskite devices by engineering an ultra-stable 2D/3D (HOOC(CH2)4NH3)2PbI4/CH3NH3PbI3 perovskite junction. The 2D/3D forms an exceptional gradually-organized multi-dimensional interface that yields up to 12.9% efficiency in a carbon-based architecture, and 14.6% in standard mesoporous solar cells. To demonstrate the up-scale potential of our technology, we fabricate 10 × 10 cm2 solar modules by a fully printable industrial-scale process, delivering 11.2% efficiency stable for >10,000 h with zero loss in performances measured under controlled standard conditions. This innovative stable and low-cost architecture will enable the timely commercialization of perovskite solar cells. PMID:28569749

One-Year stable perovskite solar cells by 2D/3D interface engineering.

PubMed

Grancini, G; Roldán-Carmona, C; Zimmermann, I; Mosconi, E; Lee, X; Martineau, D; Narbey, S; Oswald, F; De Angelis, F; Graetzel, M; Nazeeruddin, Mohammad Khaja

2017-06-01

Despite the impressive photovoltaic performances with power conversion efficiency beyond 22%, perovskite solar cells are poorly stable under operation, failing by far the market requirements. Various technological approaches have been proposed to overcome the instability problem, which, while delivering appreciable incremental improvements, are still far from a market-proof solution. Here we show one-year stable perovskite devices by engineering an ultra-stable 2D/3D (HOOC(CH 2 ) 4 NH 3 ) 2 PbI 4 /CH 3 NH 3 PbI 3 perovskite junction. The 2D/3D forms an exceptional gradually-organized multi-dimensional interface that yields up to 12.9% efficiency in a carbon-based architecture, and 14.6% in standard mesoporous solar cells. To demonstrate the up-scale potential of our technology, we fabricate 10 × 10 cm 2 solar modules by a fully printable industrial-scale process, delivering 11.2% efficiency stable for >10,000 h with zero loss in performances measured under controlled standard conditions. This innovative stable and low-cost architecture will enable the timely commercialization of perovskite solar cells.

Improvement of the photovoltaic performance of Cu2ZnSn(S x Se1-x )4 solar cells by adding polymer in the precursor solution

NASA Astrophysics Data System (ADS)

Yang, Gang; Li, Yong-Feng; Yao, Bin; Ding, Zhan-Hui; Deng, Rui; Zhao, Hai-Feng; Zhang, Li-Gong; Zhang, Zhen-Zhong

2018-03-01

Kesterite Cu2ZnSn(S x Se1-x )4 (CZTSSe) thin films and related solar cells were successfully fabricated by a facile sol-gel method and selenization process. The influence of Polyvinylpyrrolidone (PVP) additive on the properties of the CZTSSe films and the power conversion efficiency (PCE) of the solar cells were investigated. The results reveal that the qualities of CZTSSe films can be manipulated by incorporating a small amount of PVP. With addition of 1 wt% of PVP, the smoothness and grain size of the CZTSSe films were greatly improved. The contact at the CZTSSe/Mo interface was also improved. As a result, the optimized PCE of solar cells improved from 2.24% to 4.34% after the addition of 1 wt% PVP due to the decrease of recombination at the interfaces. These results suggest that polymer addition in the precursor solution is a promising method for obtaining high quality of CZTSSe films and high-performance solar cells.

Simultaneous control of multiple instruments at the Advanced Technology Solar Telescope

NASA Astrophysics Data System (ADS)

Johansson, Erik M.; Goodrich, Bret

2012-09-01

The Advanced Technology Solar Telescope (ATST) is a 4-meter solar observatory under construction at Haleakala, Hawaii. The simultaneous use of multiple instruments is one of the unique capabilities that makes the ATST a premier ground based solar observatory. Control of the instrument suite is accomplished by the Instrument Control System (ICS), a layer of software between the Observatory Control System (OCS) and the instruments. The ICS presents a single narrow interface to the OCS and provides a standard interface for the instruments to be controlled. It is built upon the ATST Common Services Framework (CSF), an infrastructure for the implementation of a distributed control system. The ICS responds to OCS commands and events, coordinating and distributing them to the various instruments while monitoring their progress and reporting the status back to the OCS. The ICS requires no specific knowledge about the instruments. All information about the instruments used in an experiment is passed by the OCS to the ICS, which extracts and forwards the parameters to the appropriate instrument controllers. The instruments participating in an experiment define the active instrument set. A subset of those instruments must complete their observing activities in order for the experiment to be considered complete and are referred to as the must-complete instrument set. In addition, instruments may participate in eavesdrop mode, outside of the control of the ICS. All instrument controllers use the same standard narrow interface, which allows new instruments to be added without having to modify the interface or any existing instrument controllers.

Origin of Photovoltage Enhancement via Interfacial Modification with Silver Nanoparticles Embedded in an a-SiC:H p-Type Layer in a-Si:H Solar Cells.

PubMed

Li, Tiantian; Zhang, Qixing; Ni, Jian; Huang, Qian; Zhang, Dekun; Li, Baozhang; Wei, Changchun; Yan, Baojie; Zhao, Ying; Zhang, Xiaodan

2017-03-29

We used silver nanoparticles (Ag-NPs) embedded in the p-type semiconductor layer of hydrogenated amorphous silicon (a-Si:H) solar cells in the Schottky barrier contact design to modify the interface between aluminum-doped ZnO (ZnO:Al, AZO) and p-type hydrogenated amorphous silicon carbide (p-a-SiC:H) without plasmonic absorption. The high work function of the Ag-NPs provided a good channel for the transport of photogenerated holes. A p-type nanocrystalline SiC:H layer was used to compensate for the real surface defects and voids on the surface of Ag-NPs to reduce recombination at the AZO/p-type layer interface, which then enhanced the photovoltage of single-junction a-Si:H solar cells to values as high as 1.01 V. The Ag-NPs were around 10 nm in diameter and thermally stable in the p-type a-SiC:H film at the solar-cell process temperature. We will also show that a wide range of photovoltages between 1.01 and 2.89 V could be obtained with single-, double-, and triple-junction solar cells based on the single-junction a-Si:H solar cells with tunable high photovoltage. These solar cells are suitable photocathodes for solar water-splitting applications.

Beyond Solar-B: MTRAP, the Magnetic Transition Region Probe

NASA Technical Reports Server (NTRS)

Davis, John M.; Moore, Ronald L.; Hathaway, David H.

2003-01-01

The next generation of solar missions will reveal and measure fine-scale solar magnetic fields and their effects in the solar atmosphere at heights, small scales, sensitivities, and fields of view well beyond the reach of Solar-B. The necessity for, and potential of, such observations for understanding solar magnetic fields, their generation in and below the photosphere, and their control of the solar atmosphere and heliosphere, were the focus of a science definition workshop, 'High-Resolution Solar Magnetography from Space: Beyond Solar-B,' held in Huntsville Alabama in April 2001. Forty internationally prominent scientists active in solar research involving fine-scale solar magnetism participated in this Workshop and reached consensus that the key science objective to be pursued beyond Solar-B is a physical understanding of the fine-scale magnetic structure and activity in the magnetic transition region, defined as the region between the photosphere and corona where neither the plasma nor the magnetic field strongly dominates the other. The observational objective requires high cadence (less than 10s) vector magnetic field maps, and spatially resolved spectra from the IR, visible, vacuum UV, to the EUV at high resolution (less than 50km) over a large FOV (approximately 140,000 km). A polarimetric resolution of one part in ten thousand is required to measure transverse magnetic fields of less than 30G. The latest SEC Roadmap includes a mission identified as MTRAP to meet these requirements. Enabling technology development requirements include large, lightweight, reflecting optics, large format sensors (16K x 16K pixels) with high QE at 150 nm, and extendable spacecraft structures. The Science Organizing Committee of the Beyond Solar-B Workshop recommends that: (1) Science and Technology Definition Teams should be established in FY04 to finalize the science requirements and to define technology development efforts needed to ensure the practicality of MTRAP's observational goals; (2) The necessary technology development funding should be included in Code S budgets for FY06 and beyond to prepare MTRAP for a new start no later than the nominal end of the Solar-B mission, around 2010.

Beyond Solar-B: MTRAP, the Magnetic TRAnsition Region Probe

NASA Astrophysics Data System (ADS)

Davis, J. M.; Moore, R. L.; Hathaway, D. H.; Science Definition CommitteeHigh-Resolution Solar Magnetography Beyond Solar-B Team

2003-05-01

The next generation of solar missions will reveal and measure fine-scale solar magnetic fields and their effects in the solar atmosphere at heights, small scales, sensitivities, and fields of view well beyond the reach of Solar-B. The necessity for, and potential of, such observations for understanding solar magnetic fields, their generation in and below the photosphere, and their control of the solar atmosphere and heliosphere, were the focus of a science definition workshop, "High-Resolution Solar Magnetography from Space: Beyond Solar-B," held in Huntsville Alabama in April 2001. Forty internationally prominent scientists active in solar research involving fine-scale solar magnetism participated in this Workshop and reached consensus that the key science objective to be pursued beyond Solar-B is a physical understanding of the fine-scale magnetic structure and activity in the magnetic transition region, defined as the region between the photosphere and corona where neither the plasma nor the magnetic field strongly dominates the other. The observational objective requires high cadence (< 10s) vector magnetic field maps, and spatially resolved spectra from the IR, visible, vacuum UV, to the EUV at high resolution (< 50km) over a large FOV ( 140,000 km). A polarimetric resolution of one part in ten thousand is required to measure transverse magnetic fields of < 30G. The latest SEC Roadmap includes a mission identified as MTRAP to meet these requirements. Enabling technology development requirements include large, lightweight, reflecting optics, large format sensors (16K x 16K pixels) with high QE at 150 nm, and extendable spacecraft structures. The Science Organizing Committee of the Beyond Solar-B Workshop recommends that: 1. Science and Technology Definition Teams should be established in FY04 to finalize the science requirements and to define technology development efforts needed to ensure the practicality of MTRAP's observational goals. 2. The necessary technology development funding should be included in Code S budgets for FY06 and beyond to prepare MTRAP for a new start no later than the nominal end of the Solar-B mission, around 2010.

Solar Probe Plus: A NASA Mission to Touch the Sun

NASA Astrophysics Data System (ADS)

Fox, N. J.; Velli, M. M. C.; Kasper, J. C.; McComas, D. J.; Howard, R.; Bale, S. D.; Decker, R. B.

2014-12-01

Solar Probe Plus (SPP), currently in Phase C, will be the first mission to fly into the low solar corona, revealing how the corona is heated and the solar wind and energetic particles are accelerated, solving fundamental mysteries that have been top priority science goals since such a mission was first proposed in 1958. The scale and concept of such a mission has been revised at intervals since that time, yet the core has always been a close encounter with the Sun. The primary science goal of the Solar Probe Plus mission is to determine the structure and dynamics of the Sun's coronal magnetic field, understand how the solar corona and wind are heated and accelerated, and determine what mechanisms accelerate and transport energetic particles. The SPP mission will achieve this by identifying and quantifying the basic plasma physical processes at the heart of the Heliosphere. SPP uses an innovative mission design, significant technology development and a risk-reducing engineering development to meet the SPP science objectives: 1) Trace the flow of energy that heats and accelerates the solar corona and solar wind; 2) Determine the structure and dynamics of the plasma and magnetic fields at the sources of the solar wind; and 3) Explore mechanisms that accelerate and transport energetic particles. In this presentation, we present Solar Probe Plus and examine how the mission will address the science questions that have remained unanswered for over 5 decades.

Semiconductor ferroelectric compositions and their use in photovoltaic devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rappe, Andrew M; Davies, Peter K; Spanier, Jonathan E

Disclosed herein are ferroelectric perovskites characterized as having a band gap, Egap, of less than 2.5 eV. Also disclosed are compounds comprising a solid solution of KNbO3 and BaNi1/2Nb1/2O3-delta, wherein delta is in the range of from 0 to about 1. The specification also discloses photovoltaic devices comprising one or more solar absorbing layers, wherein at least one of the solar absorbing layers comprises a semiconducting ferroelectric layer. Finally, this patent application provides solar cell, comprising: a heterojunction of n- and p-type semiconductors characterized as comprising an interface layer disposed between the n- and p-type semiconductors, the interface layer comprisingmore » a semiconducting ferroelectric absorber layer capable of enhancing light absorption and carrier separation.« less

Impedance analysis of PbS colloidal quantum dot solar cells with different ZnO nanowire lengths

NASA Astrophysics Data System (ADS)

Fukuda, Takeshi; Takahashi, Akihiro; Wang, Haibin; Takahira, Kazuya; Kubo, Takaya; Segawa, Hiroshi

2018-03-01

The photoconversion efficiency of colloidal quantum dot (QD) solar cells has been markedly improved by optimizing the surface passivation and device structure, and details of device physics are now under investigation. In this study, we investigated the resistance and capacitance components at the ZnO/PbS-QD interface and inside a PbS-QD layer by measuring the impedance spectrum while the interface area was controlled by changing the ZnO nanowire length. By evaluating the dependence of optical intensity and DC bias voltage on the ZnO nanowire length, only the capacitance was observed to be influenced by the interface area, and this indicates that photoinduced carriers are generated at the surface of PbS-QD. In addition, since the capacitance is proportional to the surface area of the QD, the interface area can be evaluated from the capacitance. Finally, photovoltaic performance was observed to increase with increasing ZnO nanowire length owing to the large interface area, and this result is in good agreement with the capacitance measurement.

Characterization of opto-electrical enhancement of tandem photoelectrochemical cells by using photoconductive-AFM

NASA Astrophysics Data System (ADS)

Park, Sun-Young; Elbersen, Rick; Huskens, Jurriaan; Gardeniers, Han; Lee, Joo-Yul; Mul, Guido; Heo, Jinhee

2017-07-01

Solar-to-hydrogen conversion by water splitting in photoelectrochemical cells (PECs) is a promising approach to alleviate problems associated with intermittency in solar energy supply and demand. Several interfacial resistances in photoelectrodes limit the performance of such cells, while the properties of interfaces are not easy to analyze in situ. We applied photoconductive-AFM to analyze the performance of WO3/p+n Si photoanodes, containing an ultra-thin metal interface of either Au or Pt. The Au interface consisted of Au nanoparticles with well-ordered interspacing, while Pt was present in the form of a continuous film. Photoconductive-AFM data show that upon illumination significantly larger currents are measured for the WO3/p+n Si anode equipped with the Au interface, as compared to the WO3/p+n Si anode with the Pt interface, in agreement with the better performance of the former electrode in a photoelectrochemical cell. The remarkable performance of the Au-containing electrode is proposed to be the result of favorable electron-hole recombination rates induced by the Au nanoparticles in a plasmon resonance excited state.

Inductively and capacitively coupled plasmas at interface: A comparative study towards highly efficient amorphous-crystalline Si solar cells

NASA Astrophysics Data System (ADS)

Guo, Yingnan; Ong, Thiam Min Brian; Levchenko, I.; Xu, Shuyan

2018-01-01

A comparative study on the application of two quite different plasma-based techniques to the preparation of amorphous/crystalline silicon (a-Si:H/c-Si) interfaces for solar cells is presented. The interfaces were fabricated and processed by hydrogen plasma treatment using the conventional plasma-enhanced chemical vacuum deposition (PECVD) and inductively coupled plasma chemical vapour deposition (ICP-CVD) methods The influence of processing temperature, radio-frequency power, treatment duration and other parameters on interface properties and degree of surface passivation were studied. It was found that passivation could be improved by post-deposition treatment using both ICP-CVD and PECVD, but PECVD treatment is more efficient for the improvement on passivation quality, whereas the minority carrier lifetime increased from 1.65 × 10-4 to 2.25 × 10-4 and 3.35 × 10-4 s after the hydrogen plasma treatment by ICP-CVD and PECVD, respectively. In addition to the improvement of carrier lifetimes at low temperatures, low RF powers and short processing times, both techniques are efficient in band gap adjustment at sophisticated interfaces.

NASA's Best-Observed X-Class Flare of All Time

NASA Image and Video Library

2014-05-07

This close-up of the sunspot underneath the March 29, 2014, flare shows incredible detail. The image was captured by the G-band camera at Sacramento Peak in New Mexico. This instrument can focus on only a small area at once, but provide very high resolution. Ground-based telescope data can be hindered by Earth's atmosphere, which blocks much of the sun's ultraviolet and X-ray light, and causes twinkling even in the light it does allow through. As it happens, the March 29 flare occurred at a time of day in New Mexico that often results in the best viewing times from the ground. Credit: Kevin Reardon (National Solar Observatory), Lucia Kleint (BAER Institute) -- On March 29, 2014 the sun released an X-class flare. It was observed by NASA's Interface Region Imaging Spectrograph, or IRIS; NASA's Solar Dynamics Observatory, or SDO; NASA's Reuven Ramaty High Energy Solar Spectroscopic Imager, or RHESSI; the Japanese Aerospace Exploration Agency's Hinode; and the National Solar Observatory's Dunn Solar Telescope located at Sacramento Peak in New Mexico. To have a record of such an intense flare from so many observatories is unprecedented. Such research can help scientists better understand what catalyst sets off these large explosions on the sun. Perhaps we may even some day be able to predict their onset and forewarn of the radio blackouts solar flares can cause near Earth - blackouts that can interfere with airplane, ship and military communications. Read more: 1.usa.gov/1kMDQbO Join our Google+ Hangout on May 8 at 2:30pm EST: go.nasa.gov/1mwbBEZ Credit: NASA Goddard NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Performance of Solar Proxy Options of IRI-Plas Model for Equinox Seasons

NASA Astrophysics Data System (ADS)

Sezen, Umut; Gulyaeva, Tamara L.; Arikan, Feza

2018-02-01

International Reference Ionosphere (IRI) is the most acclaimed climatic model of the ionosphere. Since 2009, the range of the IRI model has been extended to the Global Positioning System (GPS) orbital height of 20,000 km in the plasmasphere. The new model, which is called IRI extended to Plasmasphere (IRI-Plas), can input not only the ionosonde foF2 and hmF2 but also the GPS-total electron content (TEC). IRI-Plas has been provided at www.ionolab.org, where online computation of ionospheric parameters is accomplished through a user-friendly interface. The solar proxies that are available in IRI-Plas can be listed as sunspot number (SSN1), SSN2, F10.7, global electron content (GEC), TEC, IG, Mg II, Lyman-α, and GEC_RZ. In this study, ionosonde foF2 data are compared with IRI-Plas foF2 values with the Consultative Committee International Radio (CCIR) and International Union of Radio Science (URSI) model choices for each solar proxy, with or without the GPS-TEC input for the equinox months of October 2011 and March 2015. It has been observed that the best fitting model choices in Root Mean Square (RMS) and Normalized RMS (NRMS) sense are the Jet Propulsion Laboratory global ionospheric maps-TEC input with Lyman-α solar proxy option for both months. The input of TEC definitely lowers the difference between the model and ionosonde foF2 values. The IG and Mg II solar proxies produce similar model foF2 values, and they usually are the second and third best fits to the ionosonde foF2 for the midlatitude ionosphere. In high-latitude regions, Jet Propulsion Laboratory global ionospheric map-TEC inputs to IRI-Plas with Lyman-α, GEC_RZ, and TEC solar proxies are the best choices. In equatorial region, the best fitting solar proxies are IG, Lyman-α, and Mg II.

Think Scientifically: Science Hidden in a Storybook

NASA Astrophysics Data System (ADS)

Van Norden, W. M.

2012-12-01

The Solar Dynamics Observatory's Think Scientifically (TS) program links literacy and science in the elementary classroom through an engaging storybook format and hands-on, inquiry based activities. TS consists of three illustrated storybooks, each addressing a different solar science concept. Accompanying each book is a hands-on science lesson plan that emphasizes the concepts addressed in the book, as well as math, reading, and language arts activities. Written by teachers, the books are designed to be extremely user-friendly and easy to implement in classroom instruction. The objectives of the program are: (1) to increase time spent on science in elementary school classrooms, (2) to assist educators in implementing hands-on science activities that reinforce concepts from the book, (3) to increase teacher capacity and comfort in teaching solar concepts, (4) to increase student awareness and interest in solar topics, especially students in under-served and under-represented communities. Our program meets these objectives through the National Science Standards-based content delivered in each story, the activities provided in the books, and the accompanying training that teachers are offered through the program.; ;

The New Solar System

NASA Astrophysics Data System (ADS)

Beatty, J. Kelly; Collins Petersen, Carolyn; Chaikin, Andrew

1999-01-01

As the definitive guide for the armchair astronomer, The New Solar System has established itself as the leading book on planetary science and solar system studies. Incorporating the latest knowledge of the solar system, a distinguished team of researchers, many of them Principal Investigators on NASA missions, explain the solar system with expert ease. The completely-revised text includes the most recent findings on asteroids, comets, the Sun, and our neighboring planets. The book examines the latest research and thinking about the solar system; looks at how the Sun and planets formed; and discusses our search for other planetary systems and the search for life in the solar system. In full-color and heavily-illustrated, the book contains more than 500 photographs, portrayals, and diagrams. An extensive set of tables with the latest characteristics of the planets, their moon and ring systems, comets, asteroids, meteorites, and interplanetary space missions complete the text. New to this edition are descriptions of collisions in the solar system, full scientific results from Galileo's mission to Jupiter and its moons, and the Mars Pathfinder mission. For the curious observer as well as the student of planetary science, this book will be an important library acquisition. J. Kelly Beatty is the senior editor of Sky & Telescope, where for more than twenty years he has reported the latest in planetary science. A renowned science writer, he was among the first journalists to gain access to the Soviet space program. Asteroid 2925 Beatty was named on the occasion of his marriage in 1983. Carolyn Collins Petersen is an award-winning science writer and co-author of Hubble Vision (Cambridge 1995). She has also written planetarium programs seen at hundreds of facilities around the world. Andrew L. Chaikin is a Boston-based science writer. He served as a research geologist at the Smithsonian Institution's Center for Earth and Planetary Studies. He is a contributing editor to Popular Science and writes frequently for other publications.

Space Moves: Adding Movement to Solar System Lessons

ERIC Educational Resources Information Center

Jenkins, Deborah Bainer; Heidorn, Brent

2009-01-01

Earth and space science figure prominently in the National Science Education Standards for levels 5-8 (NRC 1996). The Earth in the Solar System standard focuses on students' ability to understand (1) the composition of the solar system (Earth, Moon, Sun, planets with their moons, and smaller objects like asteroids and comets) and (2) that…

A new observational approach to investigate the heliospheric interstellar wind interface - The study of extreme and far ultraviolet resonantly scattered solar radiation from neon, oxygen, carbon and nitrogen

NASA Technical Reports Server (NTRS)

Bowyer, Stuart; Fahr, Hans J.

1990-01-01

One of the outstanding uncertainties in the understanding of the heliosphere concerns the character of the interaction between the outflowing solar wind and the interstellar medium. A new possibility for obtaining information on this topic is suggested. The cosmically abundant elements neon, oxygen, carbon, and nitrogen will be affected differently at their interface passage depending upon the character of this region. Consequently, the distribution of these atoms and their ions will vary within the inner heliosphere. The study of resonantly scattered solar radiation from these species will then provide information on the nature of the interface. A preliminary evaluation of this approach has been carried out, and the results are encouraging. The relevant lines to be studied are in the extreme and far ulraviolet. The existing data in these bands are reviewed; unfortunately, past instrumentation has had insufficient resolution and sensitivity to provide useful information. The capabilities of future approved missions with capabilities in this area are evaluated.

Special issue on enabling open and interoperable access to Planetary Science and Heliophysics databases and tools

NASA Astrophysics Data System (ADS)

2018-01-01

The large amount of data generated by modern space missions calls for a change of organization of data distribution and access procedures. Although long term archives exist for telescopic and space-borne observations, high-level functions need to be developed on top of these repositories to make Planetary Science and Heliophysics data more accessible and to favor interoperability. Results of simulations and reference laboratory data also need to be integrated to support and interpret the observations. Interoperable software and interfaces have recently been developed in many scientific domains. The Virtual Observatory (VO) interoperable standards developed for Astronomy by the International Virtual Observatory Alliance (IVOA) can be adapted to Planetary Sciences, as demonstrated by the VESPA (Virtual European Solar and Planetary Access) team within the Europlanet-H2020-RI project. Other communities have developed their own standards: GIS (Geographic Information System) for Earth and planetary surfaces tools, SPASE (Space Physics Archive Search and Extract) for space plasma, PDS4 (NASA Planetary Data System, version 4) and IPDA (International Planetary Data Alliance) for planetary mission archives, etc, and an effort to make them interoperable altogether is starting, including automated workflows to process related data from different sources.

Reaching to the Star

NASA Astrophysics Data System (ADS)

Ruzhitskaya, Lanika; Speck, A.; Baldridge, S.; Briggs, J.

2014-01-01

The 2017 solar eclipse will pass over the Midwest and right over the University of Missouri in Columbia. This event presents us with a wonderful opportunity for science outreach and education programs. In preparation for this event, we use our Coronado solar telescope as a portable solar viewing observatory roving all over our campus. During these solar viewing events, students, faculty and staff have a chance to look through the telescope to discover for themselves-- and learn about-- the most prominent features of the Sun: limb darkening, sunspots, granulations, flares, prominences and filaments. Astronomy undergraduate and graduate students are on hand to answer questions and to hand out leaflets explaining the science behind these solar features. These solar observations represent excellent opportunities for those who want to know more about the Sun and its role in our lives: from solar activity to global warming; from the formation of the Sun, our planet and the entire Solar System down to the end of our Sun’s life. These events also benefit the volunteering students who learn how to explain complicated science concepts in a simple way to the general public. In addition, the portable solar observatory makes people aware about other science talks and events on our campus. These events are a great way to make people on campus aware about the upcoming solar eclipse. Over the course of the next four years we expect to have generated enough interest to be able to accomplish our goal of hosting solar eclipse festivities in August of 2017 in our football stadium in front of a massive crowd of interested observers and potential astronomy students.

Science sequence design

NASA Technical Reports Server (NTRS)

Koskela, P. E.; Bollman, W. E.; Freeman, J. E.; Helton, M. R.; Reichert, R. J.; Travers, E. S.; Zawacki, S. J.

1973-01-01

The activities of the following members of the Navigation Team are recorded: the Science Sequence Design Group, responsible for preparing the final science sequence designs; the Advanced Sequence Planning Group, responsible for sequence planning; and the Science Recommendation Team (SRT) representatives, responsible for conducting the necessary sequence design interfaces with the teams during the mission. The interface task included science support in both advance planning and daily operations. Science sequences designed during the mission are also discussed.

SAGE III Educational Outreach and Student's On-Line Atmospheric Research

NASA Astrophysics Data System (ADS)

Woods, D. C.; Moore, S. W.; Walters, S. C.

2002-05-01

Students On-Line Atmospheric Research (SOLAR) is a NASA-sponsored educational outreach program aimed at raising the level of interest in science among elementary, middle, and high school students. SOLAR is supported by, and closely linked to, NASA's Stratospheric Aerosol and Gas Experiment III (SAGE III). SAGE III, launched on a Russian METEOR 3M spacecraft in December 2001, is a key component of NASA's Earth Observing System. It will monitor the quantity and distribution of aerosols, ozone, clouds, and other important trace gases in the upper atmosphere. Early data from SAGE III indicate that the instrument is performing as expected. SAGE III measurements will extend the long-term data record established by its predecessors, SAGE I and SAGE II, which spans from 1979 to the present. In addition, SAGE III's added measurement capabilities will provide more detailed data on certain atmospheric species. SOLAR selects interesting topics related to the science issues addressed by the SAGE III experiments, and develops educational materials and projects to enhance science teaching, and to help students realize the relevance of these issues to our lives on Earth. For example, SOLAR highlights some of the major questions regarding the health of the atmosphere such as possible influences of aerosols on global climate, and atmospheric processes related to ozone depletion. The program features projects to give students hands-on experience with scientific equipment and help develop skills in collecting, analyzing, and reporting science results. SOLAR focuses on helping teachers become familiar with current research in the atmospheric sciences, helping teachers integrate SOLAR developed educational materials into their curriculum. SOLAR gives special presentations at national and regional science teacher conferences and conducts a summer teacher workshop at the NASA Langley Research Center. This poster will highlight some of the key features of the SOLAR program and will present descriptions of student projects, teacher workshops, and SOLAR resources.

Development of n-ZnO/p-Si single heterojunction solar cell with and without interfacial layer

NASA Astrophysics Data System (ADS)

Hussain, Babar

The conversion efficiency of conventional silicon (Si) photovoltaic cells has not been improved significantly during last two decades but their cost decreased dramatically during this time. However, the higher price-per-watt of solar cells is still the main bottleneck in their widespread use for power generation. Therefore, new materials need to be explored for the fabrication of solar cells potentially with lower cost and higher efficiency. The n-type zinc oxide (n-ZnO) and p-type Si (p-Si) based single heterojunction solar cell (SHJSC) is one of the several attempts to replace conventional Si single homojunction solar cell technology. There are three inadequacies in the literature related to n-ZnO/p-Si SHJSC: (1) a detailed theoretical analysis to evaluate potential of the solar cell structure, (2) inconsistencies in the reported value of open circuit voltage (VOC) of the solar cell, and (3) lower value of experimentally achieved VOC as compared to theoretical prediction based on band-bending between n-ZnO and p-Si. Furthermore, the scientific community lacks consensus on the optimum growth parameters of ZnO. In this dissertation, I present simulation and experimental results related to n-ZnO/p-Si SHJSC to fill the gaps mentioned above. Modeling and simulation of the solar cell structure are performed using PC1D and AFORS-HET software taking practical constraints into account to explore the potential of the structure. Also, unnoticed benefits of ZnO in solar cells such as an additional antireflection (AR) effect and low temperature deposition are highlighted. The growth parameters of ZnO using metal organic chemical vapor deposition and sputtering are optimized. The structural, optical, and electrical characterization of ZnO thin films grown on sapphire and Si substrates is performed. Several n-ZnO/p-Si SHJSC devices are fabricated to confirm the repeatability of the VOC. Moreover, the AR effect of ZnO while working as an n-type layer is experimentally verified. The spatial analysis for thickness uniformity and optical quality of ZnO films is carried out. These properties turn out to play a fundamental role in device performance and so far have been overlooked by the research community. Three different materials are used as a quantum buffer layer at the interface of ZnO and Si to suppress the interface states and improve the VOC. The best measured value of VOC of 359 mV is achieved using amorphous-ZnO (a-ZnO) as the buffer layer at the interface. Finally, supplementary simulations are performed to optimize the valence-band and conduction-band offsets by engineering the bandgap and electron affinity of ZnO. After we published our initial results related to the feasibility of n-ZnO/p-Si SHJSC [Sol. Energ. Mat. Sol. Cells 139 (2015) 95-100], different research groups have fabricated and reported the solar cell performance with the best efficiency of 7.1% demonstrated very recently by Pietruszka et al. [Sol. Energ. Mat. Sol. Cells 147 (2016) 164-170]. We conclude that major challenge in n-ZnO/p-Si SHJSC is to overcome Fermi-level pinning at the hetero-interface. A potential solution is to use the appropriate material as buffer layer which is confirmed by observing an improvement in VOC using a-ZnO at the interface as buffer layer. Once the interface quality is improved and the experimental value of VOC matched the theoretical prediction, the n-ZnO/p-Si SHJSC can potentially have significant contribution in solar cells industry.

Parker Solar Probe: A NASA Mission to Touch the Sun: Mission Status Update

NASA Astrophysics Data System (ADS)

Fox, N. J.

2017-12-01

The newly renamed, Parker Solar Probe (PSP) mission will be the first mission to fly into the low solar corona, revealing how the corona is heated and the solar wind and energetic particles are accelerated, solving fundamental mysteries that have been top priority science goals since such a mission was first proposed in 1958. The scale and concept of such a mission has been revised at intervals since that time, yet the core has always been a close encounter with the Sun. The primary science goal of the Parker Solar Probe mission is to determine the structure and dynamics of the Sun's coronal magnetic field, understand how the solar corona and wind are heated and accelerated, and determine what mechanisms accelerate and transport energetic particles. PSP uses an innovative mission design, significant technology development and a risk-reducing engineering development to meet the science objectives. In this presentation, we provide an update on the progress of the Parker Solar Probe mission as we prepare for the July 2018 launch.

Solar Probe Plus: A NASA Mission to Touch the SunMission Status Update

NASA Astrophysics Data System (ADS)

Fox, N. J.

2016-12-01

Solar Probe Plus (SPP), currently in Phase D, will be the first mission to fly into the low solar corona, revealing how the corona is heated and the solar wind and energetic particles are accelerated, solving fundamental mysteries that have been top priority science goals since such a mission was first proposed in 1958. The scale and concept of such a mission has been revised at intervals since that time, yet the core has always been a close encounter with the Sun. The primary science goal of the Solar Probe Plus mission is to determine the structure and dynamics of the Sun's coronal magnetic field, understand how the solar corona and wind are heated and accelerated, and determine what mechanisms accelerate and transport energetic particles. SPP uses an innovative mission design, significant technology development and a risk-reducing engineering development to meet the SPP science objectives. In this presentation, we provide an update on the progress of the Solar Probe Plus mission as we prepare for the July 2018 launch.

Junction Quality of SnO2-Based Perovskite Solar Cells Investigated by Nanometer-Scale Electrical Potential Profiling.

PubMed

Xiao, Chuanxiao; Wang, Changlei; Ke, Weijun; Gorman, Brian P; Ye, Jichun; Jiang, Chun-Sheng; Yan, Yanfa; Al-Jassim, Mowafak M

2017-11-08

Electron-selective layers (ESLs) and hole-selective layers (HSLs) are critical in high-efficiency organic-inorganic lead halide perovskite (PS) solar cells for charge-carrier transport, separation, and collection. We developed a procedure to assess the quality of the ESL/PS junction by measuring potential distribution on the cross section of SnO 2 -based PS solar cells using Kelvin probe force microscopy. Using the potential profiling, we compared three types of cells made of different ESLs but otherwise having an identical device structure: (1) cells with PS deposited directly on bare fluorine-doped SnO 2 (FTO)-coated glass; (2) cells with an intrinsic SnO 2 thin layer on the top of FTO as an effective ESL; and (3) cells with the SnO 2 ESL and adding a self-assembled monolayer (SAM) of fullerene. The results reveal two major potential drops or electric fields at the ESL/PS and PS/HSL interfaces. The electric-field ratio between the ESL/PS and PS/HSL interfaces increased in devices as follows: FTO < SnO 2 -ESL < SnO 2 + SAM; this sequence explains the improvements of the fill factor (FF) and open-circuit voltage (V oc ). The improvement of the FF from the FTO to SnO 2 -ESL cells may result from the reduction in voltage loss at the PS/HSL back interface and the improvement of V oc from the prevention of hole recombination at the ESL/PS front interface. The further improvements with adding an SAM is caused by the defect passivation at the ESL/PS interface, and hence, improvement of the junction quality. These nanoelectrical findings suggest possibilities for improving the device performance by further optimizing the SnO 2 -based ESL material quality and the ESL/PS interface.

Junction Quality of SnO 2-Based Perovskite Solar Cells Investigated by Nanometer-Scale Electrical Potential Profiling

DOE PAGES

Xiao, Chuanxiao; Wang, Changlei; Ke, Weijun; ...

2017-10-13

Electron-selective layers (ESLs) and hole-selective layers (HSLs) are critical in high-efficiency organic-inorganic lead halide perovskite (PS) solar cells for charge-carrier transport, separation, and collection. We developed a procedure to assess the quality of the ESL/PS junction by measuring potential distribution on cross-section of SnO 2-based perovskite solar cells using Kelvin probe force microscopy. Using the potential profiling, we compared three types of cells made of different ESLs but otherwise having identical device structure: cells with PS deposited directly on bare fluorine-doped SnO 2 (FTO)-coated glass; cells with an intrinsic SnO 2 thin layer on the top of FTO as anmore » effective ESL; and cells with the SnO2 ESL and adding a self-assembled monolayer (SAM) of fullerene. The results reveal two major potential drops or electric fields at the ESL/PS and PS/HSL interfaces. The electric-field ratio between the ESL/PS and PS/HSL interfaces increased in devices as follows: FTO < SnO 2-ESL < SnO 2+SAM; this sequence explains the improvements of fill factor (FF) and open-circuit voltage ( V oc). The improvement of FF from the FTO to SnO 2-ESL cells may result from the reduction in voltage lose at the PS/HSL back interface and the improvement of V oc from the prevention of hole recombination at the ESL/PS front interface. The further improvements with adding a SAM is caused by the defect passivation at the ESL/PS interface, and hence, improvement of the junction quality. Furthermore, these nanoelectrical findings suggest possibilities for improving the device performance by further optimizing the SnO2-based ESL material quality and the ESL/PS interface.« less

Junction Quality of SnO 2-Based Perovskite Solar Cells Investigated by Nanometer-Scale Electrical Potential Profiling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiao, Chuanxiao; Wang, Changlei; Ke, Weijun

Electron-selective layers (ESLs) and hole-selective layers (HSLs) are critical in high-efficiency organic-inorganic lead halide perovskite (PS) solar cells for charge-carrier transport, separation, and collection. We developed a procedure to assess the quality of the ESL/PS junction by measuring potential distribution on cross-section of SnO 2-based perovskite solar cells using Kelvin probe force microscopy. Using the potential profiling, we compared three types of cells made of different ESLs but otherwise having identical device structure: cells with PS deposited directly on bare fluorine-doped SnO 2 (FTO)-coated glass; cells with an intrinsic SnO 2 thin layer on the top of FTO as anmore » effective ESL; and cells with the SnO2 ESL and adding a self-assembled monolayer (SAM) of fullerene. The results reveal two major potential drops or electric fields at the ESL/PS and PS/HSL interfaces. The electric-field ratio between the ESL/PS and PS/HSL interfaces increased in devices as follows: FTO < SnO 2-ESL < SnO 2+SAM; this sequence explains the improvements of fill factor (FF) and open-circuit voltage ( V oc). The improvement of FF from the FTO to SnO 2-ESL cells may result from the reduction in voltage lose at the PS/HSL back interface and the improvement of V oc from the prevention of hole recombination at the ESL/PS front interface. The further improvements with adding a SAM is caused by the defect passivation at the ESL/PS interface, and hence, improvement of the junction quality. Furthermore, these nanoelectrical findings suggest possibilities for improving the device performance by further optimizing the SnO2-based ESL material quality and the ESL/PS interface.« less

Quantitative biological surface science: challenges and recent advances.

PubMed

Höök, Fredrik; Kasemo, Bengt; Grunze, Michael; Zauscher, Stefan

2008-12-23

Biological surface science is a broad, interdisciplinary subfield of surface science, where properties and processes at biological and synthetic surfaces and interfaces are investigated, and where biofunctional surfaces are fabricated. The need to study and to understand biological surfaces and interfaces in liquid environments provides sizable challenges as well as fascinating opportunities. Here, we report on recent progress in biological surface science that was described within the program assembled by the Biomaterial Interface Division of the Science and Technology of Materials, Interfaces and Processes (www.avs.org) during their 55th International Symposium and Exhibition held in Boston, October 19-24, 2008. The selected examples show that the rapid progress in nanoscience and nanotechnology, hand-in-hand with theory and simulation, provides increasingly sophisticated methods and tools to unravel the mechanisms and details of complex processes at biological surfaces and in-depth understanding of biomolecular surface interactions.

Innovative Science Experiments Using Phoenix

ERIC Educational Resources Information Center

Kumar, B. P. Ajith; Satyanarayana, V. V. V.; Singh, Kundan; Singh, Parmanand

2009-01-01

A simple, flexible and very low cost hardware plus software framework for developing computer-interfaced science experiments is presented. It can be used for developing computer-interfaced science experiments without getting into the details of electronics or computer programming. For developing experiments this is a middle path between…

Get Involved in Planetary Discoveries through New Worlds, New Discoveries

NASA Astrophysics Data System (ADS)

Shupla, Christine; Shipp, S. S.; Halligan, E.; Dalton, H.; Boonstra, D.; Buxner, S.; SMD Planetary Forum, NASA

2013-01-01

"New Worlds, New Discoveries" is a synthesis of NASA’s 50-year exploration history which provides an integrated picture of our new understanding of our solar system. As NASA spacecraft head to and arrive at key locations in our solar system, "New Worlds, New Discoveries" provides an integrated picture of our new understanding of the solar system to educators and the general public! The site combines the amazing discoveries of past NASA planetary missions with the most recent findings of ongoing missions, and connects them to the related planetary science topics. "New Worlds, New Discoveries," which includes the "Year of the Solar System" and the ongoing celebration of the "50 Years of Exploration," includes 20 topics that share thematic solar system educational resources and activities, tied to the national science standards. This online site and ongoing event offers numerous opportunities for the science community - including researchers and education and public outreach professionals - to raise awareness, build excitement, and make connections with educators, students, and the public about planetary science. Visitors to the site will find valuable hands-on science activities, resources and educational materials, as well as the latest news, to engage audiences in planetary science topics and their related mission discoveries. The topics are tied to the big questions of planetary science: how did the Sun’s family of planets and bodies originate and how have they evolved? How did life begin and evolve on Earth, and has it evolved elsewhere in our solar system? Scientists and educators are encouraged to get involved either directly or by sharing "New Worlds, New Discoveries" and its resources with educators, by conducting presentations and events, sharing their resources and events to add to the site, and adding their own public events to the site’s event calendar! Visit to find quality resources and ideas. Connect with educators, students and the public to share the exciting planetary science discoveries as they’re uncovered during this unprecedented period of solar system exploration!

Proceedings of the Flat-plate Solar Array Project Research Forum on High-efficiency Crystalline Silicon Solar Cells

NASA Technical Reports Server (NTRS)

Kachare, R.

1985-01-01

The high-efficiency crystalline silicon solar cells research forum addressed high-efficiency concepts, surface-interface effects, bulk effects, modeling and device processing. The topics were arranged into six interactive sessions, which focused on the state-of-the-art of device structures, identification of barriers to achieve high-efficiency cells and potential ways to overcome these barriers.

Hole-Accepting-Ligand-Modified CdSe QDs for Dramatic Enhancement of Photocatalytic and Photoelectrochemical Hydrogen Evolution by Solar Energy.

PubMed

Li, Xu-Bing; Liu, Bin; Wen, Min; Gao, Yu-Ji; Wu, Hao-Lin; Huang, Mao-Yong; Li, Zhi-Jun; Chen, Bin; Tung, Chen-Ho; Wu, Li-Zhu

2016-04-01

Solar H 2 evolution of CdSe QDs can be significantly enhanced simply by introducing a suitable hole-accepting-ligand for achieving efficient hole extraction and transfer at the nanoscale interfaces, which opens an effective pathway for dissociation of excitons to generate long-lived charge separation, thus improving the solar-to-fuel conversion efficiency.

Employing Lead Thiocyanate Additive to Reduce the Hysteresis and Boost the Fill Factor of Planar Perovskite Solar Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ke, Weijun; Xiao, Chuanxiao; Wang, Changlei

2016-05-04

Lead thiocyanate in the perovskite precursor can increase the grain size of a perovskite thin film and reduce the conductivity of the grain boundaries, leading to perovskite solar cells with reduced hysteresis and enhanced fill factor. A planar perovskite solar cell with grain boundary and interface passivation achieves a steady-state efficiency of 18.42%.

The Helioseismic and Magnetic Imager (HMI) Vector Magnetic Field Pipeline: Magnetohydrodynamics Simulation Module for the Global Solar Corona.

PubMed

Hayashi, K; Hoeksema, J T; Liu, Y; Bobra, M G; Sun, X D; Norton, A A

Time-dependent three-dimensional magnetohydrodynamics (MHD) simulation modules are implemented at the Joint Science Operation Center (JSOC) of the Solar Dynamics Observatory (SDO). The modules regularly produce three-dimensional data of the time-relaxed minimum-energy state of the solar corona using global solar-surface magnetic-field maps created from Helioseismic and Magnetic Imager (HMI) full-disk magnetogram data. With the assumption of a polytropic gas with specific-heat ratio of 1.05, three types of simulation products are currently generated: i) simulation data with medium spatial resolution using the definitive calibrated synoptic map of the magnetic field with a cadence of one Carrington rotation, ii) data with low spatial resolution using the definitive version of the synchronic frame format of the magnetic field, with a cadence of one day, and iii) low-resolution data using near-real-time (NRT) synchronic format of the magnetic field on a daily basis. The MHD data available in the JSOC database are three-dimensional, covering heliocentric distances from 1.025 to 4.975 solar radii, and contain all eight MHD variables: the plasma density, temperature, and three components of motion velocity, and three components of the magnetic field. This article describes details of the MHD simulations as well as the production of the input magnetic-field maps, and details of the products available at the JSOC database interface. To assess the merits and limits of the model, we show the simulated data in early 2011 and compare with the actual coronal features observed by the Atmospheric Imaging Assembly (AIA) and the near-Earth in-situ data.

Exploring what prompts ITIC to become a superior acceptor in organic solar cell by combining molecular dynamics simulation with quantum chemistry calculation.

PubMed

Pan, Qing-Qing; Li, Shuang-Bao; Duan, Ying-Chen; Wu, Yong; Zhang, Ji; Geng, Yun; Zhao, Liang; Su, Zhong-Min

2017-11-29

The interface characteristic is a crucial factor determining the power conversion efficiency of organic solar cells (OSCs). In this work, our aim is to conduct a comparative study on the interface characteristics between the very famous non-fullerene acceptor, ITIC, and a fullerene acceptor, PC71BM by combining molecular dynamics simulations with density functional theory. Based on some typical interface models of the acceptor ITIC or PC71BM and the donor PBDB-T selected from MD simulation, besides the evaluation of charge separation/recombination rates, the relative positions of Frenkel exciton (FE) states and the charge transfer states along with their oscillator strengths are also employed to estimate the charge separation abilities. The results show that, when compared with those for the PBDB-T/PC71BM interface, the CT states are more easily formed for the PBDB-T/ITIC interface by either the electron transfer from the FE state or direct excitation, indicating the better charge separation ability of the former. Moreover, the estimation of the charge separation efficiency manifests that although these two types of interfaces have similar charge recombination rates, the PBDB-T/ITIC interface possesses the larger charge separation rates than those of the PBDB-T/PC71BM interface. Therefore, the better match between PBDB-T and ITIC together with a larger charge separation efficiency at the interface are considered to be the reasons for the prominent performance of ITIC in OSCs.

Science and Technology Facility | Photovoltaic Research | NREL

Science.gov Websites

- and back-contact schemes for advanced thin-film PV solar cells. Contact materials include metals Science and Technology Facility Science and Technology Facility Solar cell, thin-film, and Development Laboratory Research in thin-film PV is accomplished in this lab with techniques used for

Hands-on Activities for Exploring the Solar System in K-14 Formal and Informal Education Settings

NASA Astrophysics Data System (ADS)

Allen, J. S.; Tobola, K. W.

2004-12-01

Introduction: Activities developed by NASA scientists and teachers focus on integrating Planetary Science activities with existing Earth science, math, and language arts curriculum. Educators may choose activities that fit a particular concept or theme within their curriculum from activities that highlight missions and research pertaining to exploring the solar system. Most of the activities use simple, inexpensive techniques that help students understand the how and why of what scientists are learning about comets, asteroids, meteorites, moons and planets. The web sites for the activities contain current information so students experience recent mission information such as data from Mars rovers or the status of Stardust sample return. The Johnson Space Center Astromaterials Research and Exploration Science education team has compiled a variety of NASA solar system activities to produce an annotated thematic syllabus useful to classroom educators and informal educators as they teach space science. An important aspect of the syllabus is that it highlights appropriate science content information and key science and math concepts so educators can easily identify activities that will enhance curriculum development. The outline contains URLs for the activities and NASA educator guides as well as links to NASA mission science and technology. In the informal setting, educators can use solar system exploration activities to reinforce learning in association with thematic displays, planetarium programs, youth group gatherings, or community events. In both the informal and the primary education levels the activities are appropriately designed to excite interest, arouse curiosity and easily take the participants from pre-awareness to the awareness stage. Middle school educators will find activities that enhance thematic science and encourage students to think about the scientific process of investigation. Some of the activities offered may easily be adapted for the upper levels of high school and early college, as they require students to use and analyze data. Syllabus Format: The Exploring the Solar System Syllabus of Activities starts with a variety of solar system scale activities that fit different settings and equipment. The early solar system formation activities are focused on asteroids, meteorites and planet formation. The theme of how and why we explore our solar system encompasses activities that engage the language and creative arts. Further activities highlight the Sun and planetary geology. A key aspect of the usefulness of the syllabus is that it provides easy access to solar system content, activities, related links and the thematic context for the classroom teacher or group leader. Conclusion: The Exploring the Solar System Syllabus of Activities is a concentrated resource of activities and links that allows educators to comfortably and inexpensively share the excitement and science of solar system exploration with students and members of the public. Additional Information: Some of the activities included in the Exploring the Solar System Syllabus of Activities are in the following NASA developed guides. http://ares.jsc.nasa.gov/Education/index.html

Web site lets solar scientists inform and inspire students

NASA Astrophysics Data System (ADS)

Hauck, Karin

2012-07-01

Where on the Web can a middle school girl ask a female solar scientist about solar storms, the course and behavior of charged solar particles, and the origin of the Sun's dynamo—and also find out what the scientist was like as a child, whether the scientist has tattoos or enjoys snowboarding, what she likes and dislikes about her career, and how she balances her energy for work and family life? These kinds of exchanges happen at Solar Week (http://www.solarweek.org; see Figure 1). Established in 2000, Solar Week is an online resource for middle and lower high school students about the science of the Sun, sponsored by the Center for Science Education at the Space Sciences Laboratory (CSE@SSL) at the University of California, Berkeley (UC Berkeley). The Web site's goals are to educate students about the Sun and solar physics and to encourage future careers in science—especially for girls. One way is by giving solar scientists the chance to be relatable role models, to answer students' questions, and to share their experiences in an online forum.

Transits in our Solar System for educational activities: Mercury Transit 2016 and Total Solar Eclipse 2017

NASA Astrophysics Data System (ADS)

Pérez-Ayúcar, M.; Breitfelner, M.

2017-09-01

Solar transits are rare astronomical event of profound historical importance and with an enormous potential to engage nowadays students and general public into Planetary Sciences and Space. Mercury transits occur only about every 13-14 times per century. Total solar eclipses occur around 18 months apart somewhere on Earth, but they recur only every 3-4 centuries on the same location. Although its historic scientific importance (examples, to measure the distances in the solar system, to observe the solar corona) has diminished since humanity roams our solar system with robotic spacecrafts, transits remain a spectacular astronomical event that is used very effectively to engage general public and students to Science and Space in general. The educational project CESAR (Cooperation through Education in Science and Astronomy Research) has been covering since 2012 such events (Venus transit 2012, live Sun transmissions, solar eclipses, ISS transits ...). We report the outstanding outcome of the two public educational and outreach events since last year: the May 2016 Mercury Transit, and the recent August 2017 Total Eclipse. And the follow up activities expected for future transits.

Reliable wet-chemical cleaning of natively oxidized high-efficiency Cu(In,Ga)Se{sub 2} thin-film solar cell absorbers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lehmann, Jascha; Potsdam Institute for Climate Impact Research; Lehmann, Sebastian, E-mail: sebastian.lehmann@ftf.lth.se

2014-12-21

Currently, Cu-containing chalcopyrite-based solar cells provide the highest conversion efficiencies among all thin-film photovoltaic (PV) technologies. They have reached efficiency values above 20%, the same performance level as multi-crystalline silicon-wafer technology that dominates the commercial PV market. Chalcopyrite thin-film heterostructures consist of a layer stack with a variety of interfaces between different materials. It is the chalcopyrite/buffer region (forming the p-n junction), which is of crucial importance and therefore frequently investigated using surface and interface science tools, such as photoelectron spectroscopy and scanning probe microscopy. To ensure comparability and validity of the results, a general preparation guide for “realistic” surfacesmore » of polycrystalline chalcopyrite thin films is highly desirable. We present results on wet-chemical cleaning procedures of polycrystalline Cu(In{sub 1-x}Ga{sub x})Se{sub 2} thin films with an average x = [Ga]/([In] + [Ga]) = 0.29, which were exposed to ambient conditions for different times. The hence natively oxidized sample surfaces were etched in KCN- or NH{sub 3}-based aqueous solutions. By x-ray photoelectron spectroscopy, we find that the KCN treatment results in a chemical surface structure which is – apart from a slight change in surface composition – identical to a pristine as-received sample surface. Additionally, we discover a different oxidation behavior of In and Ga, in agreement with thermodynamic reference data, and we find indications for the segregation and removal of copper selenide surface phases from the polycrystalline material.« less

The silane depletion fraction as an indicator for the amorphous/crystalline silicon interface passivation quality

NASA Astrophysics Data System (ADS)

Descoeudres, A.; Barraud, L.; Bartlome, R.; Choong, G.; De Wolf, Stefaan; Zicarelli, F.; Ballif, C.

2010-11-01

In silicon heterojunction solar cells, thin amorphous silicon layers passivate the crystalline silicon wafer surfaces. By using in situ diagnostics during plasma-enhanced chemical vapor deposition (PECVD), the authors report how the passivation quality of such layers directly relate to the plasma conditions. Good interface passivation is obtained from highly depleted silane plasmas. Based upon this finding, layers deposited in a large-area very high frequency (40.68 MHz) PECVD reactor were optimized for heterojunction solar cells, yielding aperture efficiencies up to 20.3% on 4 cm2 cells.

Solar-powered hot-air system

NASA Technical Reports Server (NTRS)

1979-01-01

Solar-powered air heater supplies part or all of space heating requirements of residential or commercial buildings and is interfaced with air to water heat exchanger to heat domestic hot water. System has potential application in drying agricultural products such as cotton, lumber, corn, grains, and peanuts.

The Solar Probe Plus Mission: Humanity's First Visit to Our Star

NASA Technical Reports Server (NTRS)

Fox, N. J.; Velli, M. C.; Bale, S. D.; Decker, R.; Driesman, A.; Howard, R. A.; Kasper, J. C.; Kinnison, J.; Kusterer, M.; Lario, D.;

The Solar Probe Plus Mission: Humanity's First Visit to Our Star

NASA Astrophysics Data System (ADS)

Fox, N. J.; Velli, M. C.; Bale, S. D.; Decker, R.; Driesman, A.; Howard, R. A.; Kasper, J. C.; Kinnison, J.; Kusterer, M.; Lario, D.; Lockwood, M. K.; McComas, D. J.; Raouafi, N. E.; Szabo, A.

2016-12-01

Solar Probe Plus (SPP) will be the first spacecraft to fly into the low solar corona. SPP's main science goal is to determine the structure and dynamics of the Sun's coronal magnetic field, understand how the solar corona and wind are heated and accelerated, and determine what processes accelerate energetic particles. Understanding these fundamental phenomena has been a top-priority science goal for over five decades, dating back to the 1958 Simpson Committee Report. The scale and concept of such a mission has been revised at intervals since that time, yet the core has always been a close encounter with the Sun. The mission design and the technology and engineering developments enable SPP to meet its science objectives to: (1) Trace the flow of energy that heats and accelerates the solar corona and solar wind; (2) Determine the structure and dynamics of the plasma and magnetic fields at the sources of the solar wind; and (3) Explore mechanisms that accelerate and transport energetic particles. The SPP mission was confirmed in March 2014 and is under development as a part of NASA's Living with a Star (LWS) Program. SPP is scheduled for launch in mid-2018, and will perform 24 orbits over a 7-year nominal mission duration. Seven Venus gravity assists gradually reduce SPP's perihelion from 35 solar radii (RS) for the first orbit to {<}10 RS for the final three orbits. In this paper we present the science, mission concept and the baseline vehicle for SPP, and examine how the mission will address the key science questions

Two Solar Tornadoes Observed with the Interface Region Imaging Spectrograph

NASA Astrophysics Data System (ADS)

Yang, Zihao; Tian, Hui; Peter, Hardi; Su, Yang; Samanta, Tanmoy; Zhang, Jingwen; Chen, Yajie

2018-01-01

The barbs or legs of some prominences show an apparent motion of rotation, which are often termed solar tornadoes. It is under debate whether the apparent motion is a real rotating motion, or caused by oscillations or counter-streaming flows. We present analysis results from spectroscopic observations of two tornadoes by the Interface Region Imaging Spectrograph. Each tornado was observed for more than 2.5 hr. Doppler velocities are derived through a single Gaussian fit to the Mg II k 2796 Å and Si IV 1393 Å line profiles. We find coherent and stable redshifts and blueshifts adjacent to each other across the tornado axes, which appears to favor the interpretation of these tornadoes as rotating cool plasmas with temperatures of 104 K–105 K. This interpretation is further supported by simultaneous observations of the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory, which reveal periodic motions of dark structures in the tornadoes. Our results demonstrate that spectroscopic observations can provide key information to disentangle different physical processes in solar prominences.

Fill factor in organic solar cells can exceed the Shockley-Queisser limit

NASA Astrophysics Data System (ADS)

Trukhanov, Vasily A.; Bruevich, Vladimir V.; Paraschuk, Dmitry Yu.

2015-06-01

The ultimate efficiency of organic solar cells (OSC) is under active debate. The solar cell efficiency is calculated from the current-voltage characteristic as a product of the open-circuit voltage (VOC), short-circuit current (JSC), and the fill factor (FF). While the factors limiting VOC and JSC for OSC were extensively studied, the ultimate FF for OSC is scarcely explored. Using numerical drift-diffusion modeling, we have found that the FF in OSC can exceed the Shockley-Queisser limit (SQL) established for inorganic p-n junction solar cells. Comparing charge generation and recombination in organic donor-acceptor bilayer heterojunction and inorganic p-n junction, we show that such distinctive properties of OSC as interface charge generation and heterojunction facilitate high FF, but the necessary condition for FF exceeding the SQL in OSC is field-dependence of charge recombination at the donor-acceptor interface. These findings can serve as a guideline for further improvement of OSC.

Spin-enhanced organic bulk heterojunction photovoltaic solar cells.

PubMed

Zhang, Ye; Basel, Tek P; Gautam, Bhoj R; Yang, Xiaomei; Mascaro, Debra J; Liu, Feng; Vardeny, Z Valy

2012-01-01

Recently, much effort has been devoted to improve the efficiency of organic photovoltaic solar cells based on blends of donors and acceptors molecules in bulk heterojunction architecture. One of the major losses in organic photovoltaic devices has been recombination of polaron pairs at the donor-acceptor domain interfaces. Here, we present a novel method to suppress polaron pair recombination at the donor-acceptor domain interfaces and thus improve the organic photovoltaic solar cell efficiency, by doping the device active layer with spin 1/2 radical galvinoxyl. At an optimal doping level of 3 wt%, the efficiency of a standard poly(3-hexylthiophene)/1-(3-(methoxycarbonyl)propyl)-1-1-phenyl)(6,6)C(61) solar cell improves by 18%. A spin-flip mechanism is proposed and supported by magneto-photocurrent measurements, as well as by density functional theory calculations in which polaron pair recombination rate is suppressed by resonant exchange interaction between the spin 1/2 radicals and charged acceptors, which convert the polaron pair spin state from singlet to triplet.

Interface Engineering Based on Liquid Metal for Compact-Layer-free, Fully Printable Mesoscopic Perovskite Solar Cells.

PubMed

Zhang, Yumin; Zhao, Jianhong; Zhang, Jin; Jiang, Xixi; Zhu, Zhongqi; Liu, Qingju

2018-05-09

A printing process for the fabrication of perovskite solar cells (PSCs) exhibits promising future application in the photovoltaic industry due to its low-cost and eco-friendly preparation. In mesoscopic carbon-based PSCs, however, compared to conventional ones, the hole-transport-layer-free PSCs often lead to inefficient hole extraction. Here, we used liquid metal (LM, Galinstan) as an interface modifier material in combination with a carbon electrode. Considering the high conductivity and room-temperature fluidity, it is found that LMs are superior in improving hole extraction and, more importantly, LMs tend to be reserved at the interface between ZrO 2 and carbon for enhancing the contact property. Correspondingly, the carrier transfer resistance was decreased at the carbon/perovskite interface. As optimized content, the triple mesoscopic PSCs based on mixed-cation perovskite with a power conversion efficiency of 13.51% was achieved, involving a 26% increase compared to those without LMs. This work opens new techniques for LMs in optoelectronics and printing.

A New Planet in our Solar System? NASA Takes a Look

NASA Image and Video Library

2016-01-20

NASA’s Director of Planetary Science, Jim Green, discusses the Jan. 20, 2016 Astronomical Journal science paper that points to the possibility of a new “Planet 9” in our solar system beyond Pluto, examining the scientific process and inviting you to have a front row seat to our exploration of the solar system.

Measurement of Solar Spectra Relating to Photosynthesis and Solar Cells: An Inquiry Lab for Secondary Science

ERIC Educational Resources Information Center

Ruggirello, Rachel M.; Balcerzak, Phyllis; May, Victoria L.; Blankenship, Robert E.

2012-01-01

The process of photosynthesis is central to science curriculum at all levels. This article describes an inquiry-based laboratory investigation developed to explore the impact of light quality on photosynthesis and to connect this process to current research on harvesting solar energy, including bioenergy, artificial photosynthesis, and solar…

75 FR 6414 - Consumer Interface With the Smart Grid

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-09

... OFFICE OF SCIENCE AND TECHNOLOGY POLICY Consumer Interface With the Smart Grid AGENCY: Office of Science and Technology Policy (OSTP), Executive Office of the President. ACTION: Notice; request for public comment. SUMMARY: With this notice, the Office of Science and Technology Policy (OSTP) within the...

75 FR 7526 - Consumer Interface With the Smart Grid

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-19

... OFFICE OF SCIENCE AND TECHNOLOGY POLICY Consumer Interface With the Smart Grid AGENCY: Office of Science and Technology Policy (OSTP), Executive Office of the President. ACTION: Notice; request for public comment. SUMMARY: With this notice, the Office of Science and Technology Policy (OSTP) within the...

Solar Cookers.

ERIC Educational Resources Information Center

King, Richard C.

1981-01-01

Describes the use of solar cookers in the science classroom. Includes instructions for construction of a solar cooker, an explanation of how solar cookers work, and a number of suggested activities. (DS)

Interactive Webmap-Based Science Planning for BepiColombo

NASA Astrophysics Data System (ADS)

McAuliffe, J.; Martinez, S.; Ortiz de Landaluce, I.; de la Fuente, S.

2015-10-01

For BepiColombo, ESA's Mission to Mercury, we will build a web-based, map-based interface to the Science Planning System. This interface will allow the mission's science teams to visually define targets for observations and interactively specify what operations will make up the given observation. This will be a radical departure from previous ESA mission planning methods. Such an interface will rely heavily on GIS technologies. This interface will provide footprint coverage of all existing archived data for Mercury, including a set of built-in basemaps. This will allow the science teams to analyse their planned observations and operational constraints with relevant contextual information from their own instrument, other BepiColombo instruments or from previous missions. The interface will allow users to import and export data in commonly used GIS formats, such that it can be visualised together with the latest planning information (e.g. import custom basemaps) or analysed in other GIS software. The interface will work with an object-oriented concept of an observation that will be a key characteristic of the overall BepiColombo scienceplanning concept. Observation templates or classes will be tracked right through the planning-executionprocessing- archiving cycle to the final archived science products. By using an interface that synthesises all relevant available information, the science teams will have a better understanding of the operational environment; it will enhance their ability to plan efficiently minimising or removing manual planning. Interactive 3D visualisation of the planned, scheduled and executed observations, simulation of the viewing conditions and interactive modification of the observation parameters are also being considered.

Are current sheets the boundary of fluxtubes in the solar wind? -- A study from multiple spacecraft observation

NASA Astrophysics Data System (ADS)

Li, G.; Arnold, L.; Miao, B.; Yan, Y.

2011-12-01

G. Li (1,2), L. Arnold (1), B. Miao (3) and Y. Yan (4) (1) Department of Physics, University of Alabama in Huntsville Huntsville, AL, 35899 (2) CSPAR, University of Alabama in Huntsville Huntsville, AL, 35899 (3) School of Earth and Space Sciences, University of Science and Technology of CHINA, Hefei, China (4) Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Science, Beijing 100012, China Current sheets is a common structure in the solar wind and is a significant source of solar wind MHD turbulence intermittency. The origin of these structure is presently unknown. Non-linear interactions of the solar wind MHD turbulence can spontaneously generate these structures. On the other hand, there are proposals that these structures may represent relic structures having solar origins. Using a technique developed in [1], we examine current sheets in the solar wind from multiple spacecraft. We identify the "single-peak" and "double-peak" events in the solar wind and discuss possible scenarios for these events and its implication of the origin of the current sheets. [1] Li, G., "Identify current-sheet-like structures in the solar wind", ApJL 672, L65, 2008.

KSC-2013-2728

NASA Image and Video Library

2013-06-13

VANDENBERG ABF, Calif. - The Orbital Sciences launch team monitors the Pegasus XL rocket that will lift NASA's IRIS solar observatory into orbit as the rocket and payload are moved from a hangar onto a transporter at Vandenberg Air Force Base. IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch from Vandenberg June 26. IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: VAFB/Randy Beaudoin

KSC-2013-2725

NASA Image and Video Library

2013-06-13

VANDENBERG ABF, Calif. - The Orbital Sciences launch team monitors the Pegasus XL rocket that will lift NASA's IRIS solar observatory into orbit as the rocket and payload are moved from a hangar onto a transporter at Vandenberg Air Force Base. IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch from Vandenberg June 26. IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: VAFB/Randy Beaudoin

KSC-2013-2483

NASA Image and Video Library

2013-05-29

VANDENBERG AFB, Calif. - A mission logo decal for the launch of NASA's IRIS solar observatory aboard an Orbital Sciences Pegasus XL rocket. The decal is on the side of the Pegasus. Engineers are working inside a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Randy Beaudoin

KSC-2013-2484

NASA Image and Video Library

2013-05-29

VANDENBERG AFB, Calif. - A mission logo decal for the launch of NASA's IRIS solar observatory aboard an Orbital Sciences Pegasus XL rocket. The decal is on the side of the Pegasus. Engineers are working inside a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Randy Beaudoin

KSC-2013-2729

NASA Image and Video Library

2013-06-13

VANDENBERG ABF, Calif. - The Orbital Sciences launch team monitors the Pegasus XL rocket that will lift NASA's IRIS solar observatory into orbit as the rocket and payload are moved from a hangar onto a transporter at Vandenberg Air Force Base. IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch from Vandenberg June 26. IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: VAFB/Randy Beaudoin

A Coral Sea Rehearsal for the Eclipse Megamovie

NASA Astrophysics Data System (ADS)

Hudson, H. S.; Davey, A. R.; Ireland, J.; Jones, L.; Mcintosh, S. W.; Paglierani, R.; Pasachoff, J. M.; Peticolas, L. M.; Russell, R. M.; Suarez Sola, F. I.; Sutherland, L.; Thompson, M. J.

2012-12-01

The "Eclipse on the Coral Sea" - 13/14 November 2012 (GMT/Australia) - will have happened already. Our intention is to have used this opportunity as a trial run for the eclipse in 2017, which features 1.5 hours of totality across the whole width of the continental US. Conceived first and foremost as an education and public outreach activity, the plan is to engage the public in solar science and technology by providing a way for them to include images they have taken of the solar eclipse, into a movie representation of coronal evolution in time. This project will assimilate as much eclipse photography as possible from the public. The resulting movie(s) will cover all ranges of expertise, and at the basic smartphone or hand-held digital camera level, we expect to have obtained a huge number of images in the case of good weather conditions. The capability of modern digital technology to handle such a data flow is new. The basic purpose of this and the 2017 Megamovie observations is to explore this capability and its ability to engage people from many different communities in the solar science, astronomy, mathematics, and technology. The movie in 2017, especially, may also have important science impact because of the uniqueness of the corona as seen under eclipse conditions. In this presentation we will describe our smartphone application development (see the "Transit of Venus" app for a role model here). We will also summarize data acquisition via both the app and more traditional web interfaces. Although for the Coral Sea eclipse event we don't expect to have a movie product by the time of the AGU, for the 2017 event we do intend to assemble the heterogenous data into beautiful movies within a short space of time after the eclipse. These movies may have relatively low resolution but would extend to the base of the corona. We encourage participation in the 2012 observations, noting that no total eclipse, prior to 2017, will occur in a region with good infrastructure for extended observations. The National Center for Atmospheric Research is sponsored by the National Science Foundation. The Megamovie project is supported by NSF grant AGS-1247226, and JMP's eclipse work about the eclipses of 2012 is supported by NSF grant AGS-1047726.

Genesis Radiation Environment

NASA Technical Reports Server (NTRS)

Minow, Joseph I.; Altstatt, Richard L.; Skipworth, William C.

2007-01-01

The Genesis spacecraft launched on 8 August 2001 sampled solar wind environments at L1 from 2001 to 2004. After the Science Capsule door was opened, numerous foils and samples were exposed to the various solar wind environments during periods including slow solar wind from the streamer belts, fast solar wind flows from coronal holes, and coronal mass ejections. The Survey and Examination of Eroded Returned Surfaces (SEERS) program led by NASA's Space Environments and Effects program had initiated access for the space materials community to the remaining Science Capsule hardware after the science samples had been removed for evaluation of materials exposure to the space environment. This presentation will describe the process used to generate a reference radiation Genesis Radiation Environment developed for the SEERS program for use by the materials science community in their analyses of the Genesis hardware.

Science with the solar optical telescope

NASA Technical Reports Server (NTRS)

Jordan, S. D.; Hogan, G. D.

1984-01-01

The Solar Optical Telescope (SOT) is designed to provide the solar physics community with the data necessary for solving several fundamental problems in the energetics and dynamics of the solar atmosphere. Among these problems are questions on the origin and evolution of the sun's magnetic field, heating of the outer solar atmosphere, and sources of the solar wind in the lower lying regions of the outer atmosphere. The SOT will be built under the management of NASA's Goddard Space Flight Center, with science instruments provided by teams led by Principal Investigators. The telescope will be built by the Perkin-Elmer Corporation, and the science instruments selected for the first flight will be provided by the Lockheed Palo Alto Research Laboratory (LPARL) and the California Institute of Technology, with actual construction of a combined science instrument taking place at the LPARL. The SOT has a 1.3-meter-diameter primary mirror that will be capable of achieving diffraction-limited viewing in the visible of 0.1 arc-second. This dimension is less than a hydrodynamic scale-height or a mean-free-path of a continuum photon in the solar atmosphere. Image stability will be achieved by a control system in the telescope, which moves both the primary and tertiary mirrors in tandem, and will be further enhanced by a correlation tracker in the combined science instrument. The SOT Facility is currently scheduled for its first flight on Spacelab at the beginning of the 1990's.

Solar wind and magnetosphere interactions

NASA Technical Reports Server (NTRS)

Russell, C. T.; Allen, J. H.; Cauffman, D. P.; Feynman, J.; Greenstadt, E. W.; Holzer, R. E.; Kaye, S. M.; Slavin, J. A.; Manka, R. H.; Rostoker, G.

1979-01-01

The relationship between the magnetosphere and the solar wind is addressed. It is noted that this interface determines how much of the solar plasma and field energy is transferred to the Earth's environment, and that this coupling not only varies in time, responding to major solar disturbances, but also to small changes in solar wind conditions and interplanetary field directions. It is recommended that the conditions of the solar wind and interplanetary medium be continuously monitored, as well as the state of the magnetosphere. Other recommendations include further study of the geomagnetic tail, tests of Pc 3,4 magnetic pulsations as diagnostics of the solar wind, and tests of kilometric radiation as a remote monitor of the auroral electrojet.

Ambient-Pressure X-ray Photoelectron Spectroscopy to Characterize the Solid/Liquid Interface: Probing the Electrochemical Double Layer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Favaro, Marco; Liu, Zhi; Crumlin, Ethan J.

Ambient-pressure X-ray photoelectron spectroscopy (APXPS) has contributed greatly to a wide range of research fields, including environmental science, catalysis, and electrochemistry, to name a few. The use of this technique at synchrotron facilities primarily focused on probing the solid/gas interface; however, it quickly advanced to the probing of liquid/vapor interfaces and solid/liquid interfaces through an X-ray-transparent window. Most recently, combining APXPS with “Tender” X-rays (~2.5 keV to 8 keV) on beamline 9.3.1 at the Advanced Light Source in Lawrence Berkeley National Laboratory (which can generate photoelectrons with much longer inelastic mean free paths) has enabled us to probe the solid/liquidmore » interface without needing a window. This innovation allows us to probe interfacial chemistries of electrochemically controlled solid/liquid interfaces undergoing charge transfer reactions. Lastly, these advancements have transitioned APXPS from a traditional surface science tool to an essential interface science technique.« less

Ambient-Pressure X-ray Photoelectron Spectroscopy to Characterize the Solid/Liquid Interface: Probing the Electrochemical Double Layer

DOE PAGES

Favaro, Marco; Liu, Zhi; Crumlin, Ethan J.

2017-03-31

Ambient-pressure X-ray photoelectron spectroscopy (APXPS) has contributed greatly to a wide range of research fields, including environmental science, catalysis, and electrochemistry, to name a few. The use of this technique at synchrotron facilities primarily focused on probing the solid/gas interface; however, it quickly advanced to the probing of liquid/vapor interfaces and solid/liquid interfaces through an X-ray-transparent window. Most recently, combining APXPS with “Tender” X-rays (~2.5 keV to 8 keV) on beamline 9.3.1 at the Advanced Light Source in Lawrence Berkeley National Laboratory (which can generate photoelectrons with much longer inelastic mean free paths) has enabled us to probe the solid/liquidmore » interface without needing a window. This innovation allows us to probe interfacial chemistries of electrochemically controlled solid/liquid interfaces undergoing charge transfer reactions. Lastly, these advancements have transitioned APXPS from a traditional surface science tool to an essential interface science technique.« less

Tackling the Dilemma of the Science-Policy Interface in Environmental Policy Analysis

ERIC Educational Resources Information Center

Cimorelli, Alan J.; Stahl, Cynthia H.

2005-01-01

Scientifically derived environmental indicators are central to environmental decision analysis. This article examines the interface between science (environmental indicators) and policy, and the dilemma of their integration. In the past, science has been shown to dominate many policy debates, usually with unfavorable results. The issue, therefore,…

Assessment Processes in Science across the Primary-Secondary Interface: An Australian Perspective

ERIC Educational Resources Information Center

Skamp, Keith

2016-01-01

Assessment guidelines in the "Australian Curriculum: Science" are outlined after the status and practice of science is overviewed. Available, but dated, empirical reports of teachers' assessment processes and procedures across the interface are compared. Current assessment practices are inferred from indirect research data. Two…

Current Approach in Surface Plasmons for Thin Film and Wire Array Solar Cell Applications

PubMed Central

Zhou, Keya; Guo, Zhongyi; Liu, Shutian; Lee, Jung-Ho

2015-01-01

Surface plasmons, which exist along the interface of a metal and a dielectric, have been proposed as an efficient alternative method for light trapping in solar cells during the past ten years. With unique properties such as superior light scattering, optical trapping, guide mode coupling, near field concentration, and hot-electron generation, metallic nanoparticles or nanostructures can be tailored to a certain geometric design to enhance solar cell conversion efficiency and to reduce the material costs. In this article, we review current approaches on different kinds of solar cells, such as crystalline silicon (c-Si) and amorphous silicon (a-Si) thin film solar cells, organic solar cells, nanowire array solar cells, and single nanowire solar cells. PMID:28793457

Evolving the Living With a Star Data System Definition

NASA Astrophysics Data System (ADS)

Otranto, J. F.; Dijoseph, M.

2003-12-01

NASA's Living With a Star (LWS) Program is a space weather-focused and applications-driven research program. The LWS Program is soliciting input from the solar, space physics, space weather, and climate science communities to develop a system that enables access to science data associated with these disciplines, and advances the development of discipline and interdisciplinary findings. The LWS Program will implement a data system that builds upon the existing and planned data capture, processing, and storage components put in place by individual spacecraft missions and also inter-project data management systems, including active and deep archives, and multi-mission data repositories. It is technically feasible for the LWS Program to integrate data from a broad set of resources, assuming they are either publicly accessible or allow access by permission. The LWS Program data system will work in coordination with spacecraft mission data systems and science data repositories, integrating their holdings using a common metadata representation. This common representation relies on a robust metadata definition that provides journalistic and technical data descriptions, plus linkages to supporting data products and tools. The LWS Program intends to become an enabling resource to PIs, interdisciplinary scientists, researchers, and students facilitating both access to a broad collection of science data, as well as the necessary supporting components to understand and make productive use of these data. For the LWS Program to represent science data that are physically distributed across various ground system elements, information will be collected about these distributed data products through a series of LWS Program-created agents. These agents will be customized to interface or interact with each one of these data systems, collect information, and forward any new metadata records to a LWS Program-developed metadata library. A populated LWS metadata library will function as a single point-of-contact that serves the entire science community as a first stop for data availability, whether or not science data are physically stored in an LWS-operated repository. Further, this metadata library will provide the user access to information for understanding these data including descriptions of the associated spacecraft and instrument, data format, calibration and operations issues, links to ancillary and correlative data products, links to processing tools and models associated with these data, and any corresponding findings produced using these data. The LWS may also support an active archive for solar, space physics, space weather, and climate data when these data would otherwise be discarded or archived off-line. This archive could potentially serve also as a data storage backup facility for LWS missions. The plan for the LWS Program metadata library is developed based upon input received from the solar and geospace science communities; the library's architecture is based on existing systems developed for serving science metadata. The LWS Program continues to seek constructive input from the science community, examples of both successes and failures in dealing with science data systems, and insights regarding the obstacles between the current state-of-the-practice and this vision for the LWS Program metadata library.

Impact of molybdenum out diffusion and interface quality on the performance of sputter grown CZTS based solar cells.

PubMed

Dalapati, Goutam Kumar; Zhuk, Siarhei; Masudy-Panah, Saeid; Kushwaha, Ajay; Seng, Hwee Leng; Chellappan, Vijila; Suresh, Vignesh; Su, Zhenghua; Batabyal, Sudip Kumar; Tan, Cheng Cheh; Guchhait, Asim; Wong, Lydia Helena; Wong, Terence Kin Shun; Tripathy, Sudhiranjan

2017-05-02

We have investigated the impact of Cu 2 ZnSnS 4 -Molybdenum (Mo) interface quality on the performance of sputter-grown Cu 2 ZnSnS 4 (CZTS) solar cell. Thin film CZTS was deposited by sputter deposition technique using stoichiometry quaternary CZTS target. Formation of molybdenum sulphide (MoS x ) interfacial layer is observed in sputter grown CZTS films after sulphurization. Thickness of MoS x layer is found ~142 nm when CZTS layer (550 nm thick) is sulphurized at 600 °C. Thickness of MoS x layer significantly increased to ~240 nm in case of thicker CZTS layer (650 nm) under similar sulphurization condition. We also observe that high temperature (600 °C) annealing suppress the elemental impurities (Cu, Zn, Sn) at interfacial layer. The amount of out-diffused Mo significantly varies with the change in sulphurization temperature. The out-diffused Mo into CZTS layer and reconstructed interfacial layer remarkably decreases series resistance and increases shunt resistance of the solar cell. The overall efficiency of the solar cell is improved by nearly five times when 600 °C sulphurized CZTS layer is applied in place of 500 °C sulphurized layer. Molybdenum and sulphur diffusion reconstruct the interface layer during heat treatment and play the major role in charge carrier dynamics of a photovoltaic device.

Employing Si solar cell technology to increase efficiency of ultra-thin Cu(In,Ga)Se2 solar cells.

PubMed

Vermang, Bart; Wätjen, Jörn Timo; Fjällström, Viktor; Rostvall, Fredrik; Edoff, Marika; Kotipalli, Ratan; Henry, Frederic; Flandre, Denis

2014-10-01

Reducing absorber layer thickness below 500 nm in regular Cu(In,Ga)Se 2 (CIGS) solar cells decreases cell efficiency considerably, as both short-circuit current and open-circuit voltage are reduced because of incomplete absorption and high Mo/CIGS rear interface recombination. In this work, an innovative rear cell design is developed to avoid both effects: a highly reflective rear surface passivation layer with nano-sized local point contact openings is employed to enhance rear internal reflection and decrease the rear surface recombination velocity significantly, as compared with a standard Mo/CIGS rear interface. The formation of nano-sphere shaped precipitates in chemical bath deposition of CdS is used to generate nano-sized point contact openings. Evaporation of MgF 2 coated with a thin atomic layer deposited Al 2 O 3 layer, or direct current magnetron sputtering of Al 2 O 3 are used as rear surface passivation layers. Rear internal reflection is enhanced substantially by the increased thickness of the passivation layer, and also the rear surface recombination velocity is reduced at the Al 2 O 3 /CIGS rear interface. (MgF 2 /)Al 2 O 3 rear surface passivated ultra-thin CIGS solar cells are fabricated, showing an increase in short circuit current and open circuit voltage compared to unpassivated reference cells with equivalent CIGS thickness. Accordingly, average solar cell efficiencies of 13.5% are realized for 385 nm thick CIGS absorber layers, compared with 9.1% efficiency for the corresponding unpassivated reference cells.

Employing Si solar cell technology to increase efficiency of ultra-thin Cu(In,Ga)Se2 solar cells

PubMed Central

Vermang, Bart; Wätjen, Jörn Timo; Fjällström, Viktor; Rostvall, Fredrik; Edoff, Marika; Kotipalli, Ratan; Henry, Frederic; Flandre, Denis

2014-01-01

Reducing absorber layer thickness below 500 nm in regular Cu(In,Ga)Se2 (CIGS) solar cells decreases cell efficiency considerably, as both short-circuit current and open-circuit voltage are reduced because of incomplete absorption and high Mo/CIGS rear interface recombination. In this work, an innovative rear cell design is developed to avoid both effects: a highly reflective rear surface passivation layer with nano-sized local point contact openings is employed to enhance rear internal reflection and decrease the rear surface recombination velocity significantly, as compared with a standard Mo/CIGS rear interface. The formation of nano-sphere shaped precipitates in chemical bath deposition of CdS is used to generate nano-sized point contact openings. Evaporation of MgF2 coated with a thin atomic layer deposited Al2O3 layer, or direct current magnetron sputtering of Al2O3 are used as rear surface passivation layers. Rear internal reflection is enhanced substantially by the increased thickness of the passivation layer, and also the rear surface recombination velocity is reduced at the Al2O3/CIGS rear interface. (MgF2/)Al2O3 rear surface passivated ultra-thin CIGS solar cells are fabricated, showing an increase in short circuit current and open circuit voltage compared to unpassivated reference cells with equivalent CIGS thickness. Accordingly, average solar cell efficiencies of 13.5% are realized for 385 nm thick CIGS absorber layers, compared with 9.1% efficiency for the corresponding unpassivated reference cells. PMID:26300619

Small Satellite Constellations for Geospace Sciences

NASA Astrophysics Data System (ADS)

Spence, H. E.

2016-12-01

The recent National Academy of Sciences Solar and Space Physics Decadal Survey (DS) identified community-consensus science priorities for the decade spanning 2013 - 2022. In this talk, we discuss the ways by which small satellite constellations are already and may soon accelerate progress toward achieving many of these science targets. The DS outlined four overarching science goals: (1) determine the origins of the Sun's activity and predict the variations in the space environment; (2) determine the dynamics and coupling of Earth's magnetosphere, ionosphere, and atmosphere and their response to solar and terrestrial inputs; (3) determine the interaction of the Sun with the solar system and the interstellar medium; and, (4) discover and characterize fundamental processes that occur both within the heliosphere and throughout the universe. These DS science goals provide the context for key science challenges in the three connected parts of the system that encompass all of solar and space physics, herein referred to as geospace: the Sun and heliosphere; the coupled solar wind-magnetosphere system; and, the coupled atmosphere-ionosphere-magnetosphere system. The DS further presented the role that small satellites play in resolving many of these science challenges, with a particular emphasis on the role that constellations of small satellites will play. While once considered by many as being "futuristic" or even "unrealizable", constellations of small satellites are already making important contributions to geospace science and with the promise for more to come. Using the DS as a guidepost, in this presentation, we outline representative small satellite constellation missions alread underway, some in development, and others notionally proposed over the next several years that employ small satellite constellations to tackle large science imperatives. Finally, we give examples of key small satellite technologies in development that will potentially enable great scientific return with comparatively low investments in small satellite missions.

Cation Substitution in Earth-Abundant Kesterite Photovoltaic Materials.

PubMed

Li, Jianjun; Wang, Dongxiao; Li, Xiuling; Zeng, Yu; Zhang, Yi

2018-04-01

As a promising candidate for low-cost and environmentally friendly thin-film photovoltaics, the emerging kesterite-based Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cells have experienced rapid advances over the past decade. However, the record efficiency of CZTSSe solar cells (12.6%) is still significantly lower than those of its predecessors Cu(In,Ga)Se 2 (CIGS) and CdTe thin-film solar cells. This record has remained for several years. The main obstacle for this stagnation is unanimously attributed to the large open-circuit voltage ( V OC ) deficit. In addition to cation disordering and the associated band tailing, unpassivated interface defects and undesirable energy band alignment are two other culprits that account for the large V OC deficit in kesterite solar cells. To capture the great potential of kesterite solar cells as prospective earth-abundant photovoltaic technology, current research focuses on cation substitution for CZTSSe-based materials. The aim here is to examine recent efforts to overcome the V OC limit of kesterite solar cells by cation substitution and to further illuminate several emerging prospective strategies, including: i) suppressing the cation disordering by distant isoelectronic cation substitution, ii) optimizing the junction band alignment and constructing a graded bandgap in absorber, and iii) engineering the interface defects and enhancing the junction band bending.

Cation Substitution in Earth‐Abundant Kesterite Photovoltaic Materials

PubMed Central

Li, Jianjun; Wang, Dongxiao; Li, Xiuling; Zeng, Yu

2018-01-01

Abstract As a promising candidate for low‐cost and environmentally friendly thin‐film photovoltaics, the emerging kesterite‐based Cu2ZnSn(S,Se)4 (CZTSSe) solar cells have experienced rapid advances over the past decade. However, the record efficiency of CZTSSe solar cells (12.6%) is still significantly lower than those of its predecessors Cu(In,Ga)Se2 (CIGS) and CdTe thin‐film solar cells. This record has remained for several years. The main obstacle for this stagnation is unanimously attributed to the large open‐circuit voltage (V OC) deficit. In addition to cation disordering and the associated band tailing, unpassivated interface defects and undesirable energy band alignment are two other culprits that account for the large V OC deficit in kesterite solar cells. To capture the great potential of kesterite solar cells as prospective earth‐abundant photovoltaic technology, current research focuses on cation substitution for CZTSSe‐based materials. The aim here is to examine recent efforts to overcome the V OC limit of kesterite solar cells by cation substitution and to further illuminate several emerging prospective strategies, including: i) suppressing the cation disordering by distant isoelectronic cation substitution, ii) optimizing the junction band alignment and constructing a graded bandgap in absorber, and iii) engineering the interface defects and enhancing the junction band bending. PMID:29721421

Tuning Transpiration by Interfacial Solar Absorber‐Leaf Engineering

PubMed Central

Zhuang, Shendong; Zhou, Lin; Xu, Weichao; Xu, Ning; Hu, Xiaozhen; Li, Xiuqiang; Lv, Guangxin; Zheng, Qinghui; Zhu, Shining

2017-01-01

Abstract Plant transpiration, a process of water movement through a plant and its evaporation from aerial parts especially leaves, consumes a large component of the total continental precipitation (≈48%) and significantly influences global water distribution and climate. To date, various chemical and/or biological explorations have been made to tune the transpiration but with uncertain environmental risks. In recent years, interfacial solar steam/vapor generation is attracting a lot of attention for achieving high energy transfer efficiency. Various optical and thermal designs at the solar absorber–water interface for potential applications in water purification, seawater desalination, and power generation appear. In this work, the concept of interfacial solar vapor generation is extended to tunable plant transpiration by showing for the first time that the transpiration efficiency can also be enhanced or suppressed through engineering the solar absorber–leaf interface. By tuning the solar absorption of membrane in direct touch with green leaf, surface temperature of green leaf will change accordingly because of photothermal effect, thus the transpiration efficiency as well as temperature and relative humidity in the surrounding environment will be tuned. This tunable transpiration by interfacial absorber‐leaf engineering can open an alternative avenue to regulate local atmospheric temperature, humidity, and eventually hydrologic cycle. PMID:29619300

Graphene, conducting polymer and their composites as transparent and current spreading electrode in GaN solar cells

NASA Astrophysics Data System (ADS)

Mahala, Pramila; Kumar, Ajay; Nayak, Sasmita; Behura, Sanjay; Dhanavantri, Chenna; Jani, Omkar

2016-04-01

Understanding the physics of charge carrier transport at graphene/p-GaN interface is critical for achieving efficient device functionality. Currently, the graphene/p-GaN interface is being explored as light emitting diodes, however this interface can be probed as a potential photovoltaic cell. We report the intimate interfacing of mechanically exfoliated graphene (EG), conducting polymer (PEDOT:PSS) and composite of reduced graphene oxide (rGO) and PEDOT:PSS with a wide band gap p-GaN layer. To explore their potential in energy harvesting, three heterojunction devices such as: (i) EG/p-GaN/sapphire, (ii) PEDOT:PSS/p-GaN/sapphire and (iii) PEDOT:PSS(rGO)/p-GaN/sapphire are designed and their photovoltaic characteristics are examined. It is interesting to observe that the EG/p-GaN/sapphire solar cell exhibits high open-circuit voltage of 0.545 V with low ideality factor and reverse saturation current. However, improved short circuit current density (13.7 mA/cm2) is noticed for PEDOT:PSS/p-GaN/sapphire solar cell because of enhanced conductivity accompanied by high transmittance for PEDOT:PSS. Further, the low series resistance for PEDOT:PSS(rGO)/p-GaN/sapphire is observed suggesting that the PEDOT:PSS and rGO composite is well dispersed and exhibits low interfacial resistances with p-GaN. The present investigation leverages the potential of graphene, conducting polymer and their composites as dual capability of (a) transparent and current spreading electrode and (b) an active top layer to make an intimate contact with wide bandgap p-type GaN for possible prospect towards high performance diodes, switches and solar cells.

Nondestructive Investigation of Heterojunction Interfacial Properties Using Two-Wavelength Raman Spectroscopy on Thin-Film CdS/CdTe Solar Cells.

PubMed

Zeng, Guanggen; Harrison, Paul; Kidman, Ali; Al-Mebir, Alaa; Feng, Lianghuan; Wu, Judy

2016-09-01

Raman spectra specific to CdS and CdTe were obtained on the CdS/CdTe heterojunction interface by employing two excitation wavelengths of λ1 = 488 nm and λ2 = 633 nm, respectively, from the glass side of Glass/FTO/CdS/CdTe/HgTe:Cu:graphite/Ag solar cells fabricated using pulsed-laser deposition (PLD). This two-wavelength Raman spectroscopy approach, with one wavelength selected below the absorption edge of the window layer (λ2 in this case), allows nondestructive characterization of the CdS/CdTe heterojunction and therefore correlation of the interfacial properties with the solar cell performance. In this study, the evolution of the interfacial strain relaxation during cell fabrication process was found to be affected not only by the inter-diffusion of S and Te corresponding to the formation of CdSxTe1-x ternary alloy with a various x from ∼0.01 to ∼0.067, but also by the variation in misfit dislocations (MDs) at CdS/CdTe interface from Raman TO/LO ratio ∼2.85 for as-deposited sample to TO/LO ∼4.44 for the cells post treatment. This is consistent with the change of the Urbach energy from 0.03 eV to 0.09 eV, indicative of the deterioration of crystalline quality of CdTe at interface although improved CdTe crystalline quality was observed away from the interface after the CdCl2 annealing. This difference crucially impacted on the rectification characteristics of the CdS/CdTe heterojunction and therefore the solar cell performance. © The Author(s) 2016.

Findings from an Independent Evaluation of the AMNH's Online Seminars on Science Course: "The Solar System"

ERIC Educational Resources Information Center

Inverness Research, 2009

2009-01-01

Inverness Research studied the American Museum of Natural History (AMNH) Seminars on Science program for eight years, from its inception in 1998 to 2006. In 2009, Inverness Research conducted additional studies of the AMNH's new online course, The Solar System. This paper presents teacher survey ratings for The Solar System, along with profiles of…

Thermal Storage Applications Workshop. Volume 2: Contributed Papers

NASA Technical Reports Server (NTRS)

1979-01-01

The solar thermal and the thermal and thermochemical energy storage programs are described as well as the technology requirements for both external (electrical) and internal (thermal, chemical) modes for energy storage in solar power plants. Specific technical issues addressed include thermal storage criteria for solar power plants interfacing with utility systems; optimal dispatch of storage for solar plants in a conventional electric grid; thermal storage/temperature tradeoffs for solar total energy systems; the value of energy storage for direct-replacement solar thermal power plants; systems analysis of storage in specific solar thermal power applications; the value of seasonal storage of solar energy; criteria for selection of the thermal storage system for a 10 MW(2) solar power plant; and the need for specific requirements by storage system development teams.

The Long Wavelength Array (LWA): A Large HF/VHF Array for Solar Physics, Ionospheric Science, and Solar Radar

DTIC Science & Technology

2010-09-01

adds an extra dimension to both IPS and other observations. The polarization of the CME synchrotron emission observed by [3] will be of great...base funding. 8. REFERENCES 1. Kassim et al., The 74 MHz System on the Very Large Array, The Astrophysical Journal Supplement Series, Vol. 172...The Long Wavelength Array (LWA): A Large HF/VHF Array for Solar Physics, Ionospheric Science, and Solar Radar Namir E. Kassim Naval Research

The Solar Probe mission - Mission design concepts and requirements

NASA Technical Reports Server (NTRS)

Ayon, Juan A.

1992-01-01

The Solar Probe concept as studied by the Jet Propulsion Laboratory represents the first mission to combine out-of-the-ecliptic scientific coverage with multiple, close solar encounters (at 4 solar radii). The scientific objectives of the mission have driven the investigation and analysis of several mission design concepts, all optimized to meet the science/mission requirements. This paper reviews those mission design concepts developed, the science objectives that drive the mission design, and the principle mission requirements associated with these various concepts.

Space telescopes planetary monitoring (PM) and Zvezdny (eng. star) patrol (ZP) for planetary science and exoplanets exploration

NASA Astrophysics Data System (ADS)

Tavrov, Alexander; Frolov, Pavel; Korablev, Oleg; Vedenkin, Nikolai; Barabanov, Sergey

2017-11-01

Solar System planetology requires a wide use of observing spectroscopy for surface geology to atmosphere climatology. A high-contrast imaging is required to study and to characterize extra-solar planetary systems among other faint astronomical targets observed in the vicinity of bright objects. Two middle class space telescopes projects aimed to observe Solar system planets by a long term monitoring via spectroscopy and polarimetry. Extra solar planets (exoplanets) engineering and scientific explorations are included in science program.

Versatile dual organic interface layer for performance enhancement of polymer solar cells

NASA Astrophysics Data System (ADS)

Li, Zhiqi; Liu, Chunyu; Zhang, Zhihui; Li, Jinfeng; Zhang, Liu; Zhang, Xinyuan; Shen, Liang; Guo, Wenbin; Ruan, Shengping

2016-11-01

The electron transport layer plays a crucial role on determining electron injection and extraction, resulting from the effect of balancing charge transport and reducing the interfacial energy barrier. Decreasing the inherent incompatibility and enhancing electrical contact via employing appropriate buffer layer at the surface of hydrophobic organic active layer and hydrophilic inorganic electrode are also essential for charge collection. Herein, we demonstrate that an efficient dual polyelectrolytes interfacial layer composed of polyethylenimine (PEI) and conducting poly(9,9-dihexylfluorenyl-2,7-diyl) (PDHFD) is incorporated to investigate the interface energetics and electron transport in polymer solar cells (PSCs). The composited PEI/PDHFD interface layer (PPIL) overcomed the low conductivity of bare PEI polymer, which decreased series resistance and facilitated electron extraction at the ITO/PPIL-active layer interface. The introduction of the interface energy state of the PPIL reduced the work function of ITO so that it can mate the top of the valence band of the photoactive materials and promoted the formation of ohmic contact at ITO electrode interface. As a result, the composited PPIL tuned energy alignment and accelerated the electron transfer, leading to significantly increased photocurrent and power conversion efficiency (PCE) of the devices based on various representative polymer:fullerene systems.

Concepts and Methods of Measuring Productivity at the Organization Level

DTIC Science & Technology

1993-09-01

Interfaces, The Institute of Management Sciences, 1987. Anderson, D. et al., An Introduction to Management Science, West Publishing Co., 1991... to Management Science, West Publishing Co., 1991. Anthony, G. M., "IEs Measure Work, Write Standards for White Collar Workers at Financial...Plant Productivity Measure for ’High-Tech’ Manufacturing, Interfaces, The Institute of Management Sciences, 1987. Anderson, D. et al., An Introduction

Icarus Investigations: A Model for Engaging Citizen Scientists to Solve Solar Big Data Challenges

NASA Astrophysics Data System (ADS)

Winter, H. D., III; Loftus, K.

2017-12-01

Solar data is growing at an exponential rate. NASA's Atmospheric Imaging Assembly (AIA) has produced a data volume of over 6 petabytes to date, and that volume is growing. The initial suite of instruments on DKIST are expected to generate approximately 25TB of data per day, with bursts up to 50TB. Making sense of this deluge of solar data is as formidable a task as collecting it. New techniques and new ways of thinking are needed in order to optimize the value of this immense amount of data. While machine learning algorithms are a natural tool to sift through Big Data, those tools need to be carefully constructed and trained in order to provide meaningful results. Trained volunteers are needed to provide a large volume of initial classifications in order to properly train machine learning algorithms. To retain a highly trained pool of volunteers to teach machine learning algorithms, we propose to host an ever-changing array of solar-based citizen science projects under a single collaborative project banner: Icarus Investigations. Icarus Investigations would build and retain a dedicated user base within Zooniverse, the most popular citizen science website with over a million registered users. Volunteers will become increasingly comfortable with solar images and solar features of interest as they work on projects that focus on a wide array of solar phenomena. Under a unified framework, new solar citizen science projects submitted to Icarus Investigations will build on the successes, and learn from the missteps, of their predecessors. In this talk we discuss the importance and benefits of engaging the public in citizen science projects and call for collaborators on future citizen science projects. We will also demonstrate the initial Icarus Investigations project, The Where of the Flare. This demonstration will allow us to highlight the workflow of a Icarus Investigations citizen science project with a concrete example.

The Micro-Instrumentation Package: A Solution to Lightweight Ballooning

NASA Astrophysics Data System (ADS)

Juneau, Jill

This paper discusses the design and testing of an over the horizon (OTH) light weight telemetry and termination system that can be used for small ballooning payloads. Currently, the Columbia Scientific Balloon Facility (CSBF) provides telemetry for the science payload by integrating one of two types of support packages. The type of support package integrated depends on whether the flight will stay in range of line of sight (LOS) or will exceed LOS requiring the use of over the horizon (OTH) telemetry. The weights of these systems range from 100 pounds to 350 pounds depending upon the use of redundant systems, equipment for high data rates, and batteries and/or solar panels for power requirements. These weight values are not as significant for larger payloads but can be crippling for smaller payloads. In addition, these support package systems are fairly expensive, placing a high importance on recovery. A lightweight and inexpensive telemetry system could be beneficial for various reasons. First, it would allow scientists to fly lightweight payloads on large balloons reaching even higher altitudes. Second, scientists could fly lightweight payloads on less expensive balloons such as meteorological balloons. Depending on the payload, these flights could be fairly inexpensive and even disposable. Third, a compact telemetry system on any balloon will free up more room for the science portion of the payload. In response, a compact telemetry/termination system called the Micro-Instrumentation Package (MIP) was developed. The MIP provides uplink and downlink communications, an interface to the science, housekeeping information including global positioning system (GPS) position, and relays. Instead of a power-hungry microprocessor, the MIP's central consists of a microcontroller. Microcontrollers are lower power, easily programmed, and can be purchased for less than ten dollars. For uplink and downlink telemetry, the MIP uses an LOS serial transceiver and an Iridium unit for OTH flights. A relay deck is also included for powering subsystems and for flight termination. Furthermore, the science will be able to interface to the MIP through a serial connection, although the data rates for the science interface will be limited compared to those of standard telemetry support packages. Overall, the MIP provides the basic necessities for the safe operation of a balloon flight without the weight and the expense of the current CSBF telemetry support packages. This paper will explain more about CSBF operations and delve further into the MIP development, testing and capabilities.

Simulation of silicon thin-film solar cells for oblique incident waves

NASA Astrophysics Data System (ADS)

Jandl, Christine; Hertel, Kai; Pflaum, Christoph; Stiebig, Helmut

2011-05-01

To optimize the quantum efficiency (QE) and short-circuit current density (JSC) of silicon thin-film solar cells, one has to study the behavior of sunlight in these solar cells. Simulations are an adequate and economic method to analyze the optical properties of light caused by absorption and reflection. To this end a simulation tool is developed to take several demands into account. These include the analysis of perpendicular and oblique incident waves under E-, H- and circularly polarized light. Furthermore, the topology of the nanotextured interfaces influences the efficiency and therefore also the short-circuit current density. It is well known that a rough transparent conductive oxide (TCO) layer increases the efficiency of solar cells. Therefore, it is indispensable that various roughness profiles at the interfaces of the solar cell layers can be modeled in such a way that atomic force microscope (AFM) scan data can be integrated. Numerical calculations of Maxwell's equations based on the finite integration technique (FIT) and Finite Difference Time Domain (FDTD) method are necessary to incorporate all these requirements. The simulations are performed in parallel on high performance computers (HPC) to meet the large computational requirements.

Advanced interface modelling of n-Si/HNO3 doped graphene solar cells to identify pathways to high efficiency

NASA Astrophysics Data System (ADS)

Zhao, Jing; Ma, Fa-Jun; Ding, Ke; Zhang, Hao; Jie, Jiansheng; Ho-Baillie, Anita; Bremner, Stephen P.

2018-03-01

In graphene/silicon solar cells, it is crucial to understand the transport mechanism of the graphene/silicon interface to further improve power conversion efficiency. Until now, the transport mechanism has been predominantly simplified as an ideal Schottky junction. However, such an ideal Schottky contact is never realised experimentally. According to literature, doped graphene shows the properties of a semiconductor, therefore, it is physically more accurate to model graphene/silicon junction as a Heterojunction. In this work, HNO3-doped graphene/silicon solar cells were fabricated with the power conversion efficiency of 9.45%. Extensive characterization and first-principles calculations were carried out to establish an advanced technology computer-aided design (TCAD) model, where p-doped graphene forms a straddling heterojunction with the n-type silicon. In comparison with the simple Schottky junction models, our TCAD model paves the way for thorough investigation on the sensitivity of solar cell performance to graphene properties like electron affinity. According to the TCAD heterojunction model, the cell performance can be improved up to 22.5% after optimizations of the antireflection coatings and the rear structure, highlighting the great potentials for fabricating high efficiency graphene/silicon solar cells and other optoelectronic devices.

Axisymmetric Self-Consistent Model of the Solar Wind Interaction with the Lism: Basic Results and Possible Ways of Development

NASA Astrophysics Data System (ADS)

Baranov, V. B.; Malama, Yu. G.

1996-10-01

We analyze the main results of the axisymmetric self-consistent model of the solar wind (SW) and supersonic local interstellar medium (LISM) interaction proposed by Baranov and Malama (1993, hereafter BM93, 1995) for an interstellar flow assumed to be composed of protons, electrons and hydrogen atoms. Here, in addition to the resonant charge exchange we also take into account the photoionization and the ionization by electron impact. The characteristics of the plasma in the interface region and inside the heliosphere depend strongly on the ionization degree of the LISM. The distribution function of the H atoms which penetrate the solar system from the LISM is non-Maxwellian, which implies that a pure hydrodynamic description of their motion is not appropriate. The H atom number density is a non-monotonic function of the heliocentric distance and the existence of a “hydrogen wall” in the vicinity of the heliopause is important for the interpretation of solar Lyman-alpha scattering experiments. The influence of the interface plasma structure on the interstellar oxygen penetration into the solar system is also illustrated. Possible ways of development of the model are analyzed.

A Solar Station for Education and Research on Solar Activity at a National University in Peru

NASA Astrophysics Data System (ADS)

Ishitsuka, J. K.

2006-11-01

pepe@geo.igp.gob.pe Beginning in 1937, the Carnegie Institution of Washington made active regional observations with a spectro-helioscope at the Huancayo Observatory. In 1957, during the celebration of the International Geophysical Year Mutsumi Ishitsuka arrived at the Geophysical Institute of Peru and restarted solar observations from the Huancayo Observatory. Almost 69 years have passed and many contributions for the geophysical and solar sciences have been made. Now the Instituto Geofisico del Peru (IGP), in cooperation with the Faculty of Sciences of the Universidad Nacional San Luis Gonzaga de Ica (UNICA), and with the support of the National Astronomical Observatory of Japan, are planning to construct a solar station refurbishing a coelostat that worked for many years at the Huancayo Observatory. A 15 cm refractor telescope is already installed at the university, for the observation of sunspots. A solar Flare Monitor Telescope (FMT) from Hida Observatory of Kyoto University could be sent to Peru and installed at the solar station at UNICA. As the refurbished coelostat, FMT will become a good tool to improve education and research in sciences.

A Small Mission Concept to the Sun-Earth Lagrangian L5 Point for Innovative Solar, Heliospheric and Space Weather Science

NASA Technical Reports Server (NTRS)

Lavraud, B.; Liu, Y.; Segura, K.; He, J.; Qin, G.; Temmer, M.; Vial, J.-C.; Xiong, M.; Davies, J. A.; Rouillard, A. P.;

A small mission concept to the Sun-Earth Lagrangian L5 point for innovative solar, heliospheric and space weather science

NASA Astrophysics Data System (ADS)

Lavraud, B.; Liu, Y.; Segura, K.; He, J.; Qin, G.; Temmer, M.; Vial, J.-C.; Xiong, M.; Davies, J. A.; Rouillard, A. P.; Pinto, R.; Auchère, F.; Harrison, R. A.; Eyles, C.; Gan, W.; Lamy, P.; Xia, L.; Eastwood, J. P.; Kong, L.; Wang, J.; Wimmer-Schweingruber, R. F.; Zhang, S.; Zong, Q.; Soucek, J.; An, J.; Prech, L.; Zhang, A.; Rochus, P.; Bothmer, V.; Janvier, M.; Maksimovic, M.; Escoubet, C. P.; Kilpua, E. K. J.; Tappin, J.; Vainio, R.; Poedts, S.; Dunlop, M. W.; Savani, N.; Gopalswamy, N.; Bale, S. D.; Li, G.; Howard, T.; DeForest, C.; Webb, D.; Lugaz, N.; Fuselier, S. A.; Dalmasse, K.; Tallineau, J.; Vranken, D.; Fernández, J. G.

2016-08-01

We present a concept for a small mission to the Sun-Earth Lagrangian L5 point for innovative solar, heliospheric and space weather science. The proposed INvestigation of Solar-Terrestrial Activity aNd Transients (INSTANT) mission is designed to identify how solar coronal magnetic fields drive eruptions, mass transport and particle acceleration that impact the Earth and the heliosphere. INSTANT is the first mission designed to (1) obtain measurements of coronal magnetic fields from space and (2) determine coronal mass ejection (CME) kinematics with unparalleled accuracy. Thanks to innovative instrumentation at a vantage point that provides the most suitable perspective view of the Sun-Earth system, INSTANT would uniquely track the whole chain of fundamental processes driving space weather at Earth. We present the science requirements, payload and mission profile that fulfill ambitious science objectives within small mission programmatic boundary conditions.

On the Role of Interfaces in Planar-Structured HC(NH2 )2 PbI3 Perovskite Solar Cells.

PubMed

Seol, Dong-Jin; Lee, Jin-Wook; Park, Nam-Gyu

2015-07-20

Planar-structured HC(NH2 )2 PbI3 (FAPbI3 ) perovskite solar cells were prepared via a two-step deposition process. To investigate the role of interface, the perovskite morphology was intentionally modified by varying HC(NH2 )2 I concentration. Surface and grain sizes of the deposited FAPbI3 became rougher and larger as the HC(NH2 )2 I concentration decreased from 58.2 to 40.7 mM. Average photocurrent was improved but photovoltage deteriorated slightly with decreasing concentration. Consequently, the average efficiency was improved from 7.82 % to 10.70 % and the best efficiency of 12.17 % was obtained at 40.7 mM. Photoluminescence (PL) at TiO2 /FAPbI3 interface was reduced with decreasing concentration, which was, however, reversed at FAPbI3 /spiro-MeOTAD one. By correlating PL data and the photovoltaic performance, we concluded that the TiO2 /perovskite interface plays a crucial role in determining photocurrent while the perovskite/spiro-MeOTAD interface is important in governing photovoltage. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evidence for Chemical and Electronic Nonuniformities in the Formation of the Interface of RbF-Treated Cu(In,Ga)Se2 with CdS.

PubMed

Nicoara, Nicoleta; Kunze, Thomas; Jackson, Philip; Hariskos, Dimitrios; Duarte, Roberto Félix; Wilks, Regan G; Witte, Wolfram; Bär, Marcus; Sadewasser, Sascha

2017-12-20

We report on the initial stages of CdS buffer layer formation on Cu(In,Ga)Se 2 (CIGSe) thin-film solar cell absorbers subjected to rubidium fluoride (RbF) postdeposition treatment (PDT). A detailed characterization of the CIGSe/CdS interface for different chemical bath deposition (CBD) times of the CdS layer is obtained from spatially resolved atomic and Kelvin probe force microscopy and laterally integrating X-ray spectroscopies. The observed spatial inhomogeneity in the interface's structural, chemical, and electronic properties of samples undergoing up to 3 min of CBD treatments is indicative of a complex interface formation including an incomplete coverage and/or nonuniform composition of the buffer layer. It is expected that this result impacts solar cell performance, in particular when reducing the CdS layer thickness (e.g., in an attempt to increase the collection in the ultraviolet wavelength region). Our work provides important findings on the absorber/buffer interface formation and reveals the underlying mechanism for limitations in the reduction of the CdS thickness, even when an alkali PDT is applied to the CIGSe absorber.

Measurement of solar spectra relating to photosynthesis and solar cells: an inquiry lab for secondary science.

PubMed

Ruggirello, Rachel M; Balcerzak, Phyllis; May, Victoria L; Blankenship, Robert E

2012-07-01

The process of photosynthesis is central to science curriculum at all levels. This article describes an inquiry-based laboratory investigation developed to explore the impact of light quality on photosynthesis and to connect this process to current research on harvesting solar energy, including bioenergy, artificial photosynthesis, and solar cells. This laboratory was used with high-school science teachers who then took this experience back to their classrooms. During this exercise, teachers used an economical spectroradiometer to measure the solar spectrum and relate this to photosynthetic light absorption by determining the quality of light beneath trees. Following this investigation, teachers learned about the plant-inspired dye-sensitized solar cells and constructed one. To connect their light quality investigation to the efficiency of photosynthesis and solar cells, teachers then collected data at locations with varying quality and intensity of light. In sum, this investigation provides a crucial connection between photosynthesis and cutting edge research on solar energy technologies. Our learning experience provides a new instructional model for understanding a little investigated aspect of photosynthesis and connects to authentic scientific research. Copyright © 2012 Wiley Periodicals, Inc.

Recent Advances in Solar Sail Propulsion at NASA

NASA Technical Reports Server (NTRS)

Johnson, Les; Young, Roy M.; Montgomery, Edward E., IV

2006-01-01

Supporting NASA's Science Mission Directorate, the In-Space Propulsion Technology Program is developing solar sail propulsion for use in robotic science and exploration of the solar system. Solar sail propulsion will provide longer on-station operation, increased scientific payload mass fraction, and access to previously inaccessible orbits for multiple potential science missions. Two different 20-meter solar sail systems were produced and successfully completed functional vacuum testing last year in NASA Glenn's Space Power Facility at Plum Brook Station, Ohio. The sails were designed and developed by ATK Space Systems and L'Garde, respectively. These sail systems consist of a central structure with four deployable booms that support the sails. This sail designs are robust enough for deployments in a one atmosphere, one gravity environment, and are scalable to much larger solar sails-perhaps as much as 150 meters on a side. In addition, computation modeling and analytical simulations have been performed to assess the scalability of the technology to the large sizes (>150 meters) required for first generation solar sails missions. Life and space environmental effects testing of sail and component materials are also nearly complete. This paper will summarize recent technology advancements in solar sails and their successful ambient and vacuum testing.

Solar System Planetary Science Decadal Survey and Missions in the Next Decade, 2013-2022

NASA Technical Reports Server (NTRS)

Reh, Kim

2011-01-01

In 2010, the National Research Council Space Studies Board established a decadal survey committee to develop a comprehensive science, mission, and technology strategy for planetary science that updates and extends the Board's 2003 Solar System Exploration Decadal Survey, "New Frontiers in the Solar System: An Integrated Exploration Strategy." The scope of the survey encompasses the inner planets (Mercury, Venus, and Mars), the Earth's Moon, the giant planets (Jupiter, Saturn, Uranus, and Neptune), the moons of the giant planets, dwarf planets and small bodies, primitive bodies including comets and Kuiper Belt objects, and astrobiology. Over this past year, the decadal survey committee has interacted with the broad solar system science community to determine the current state of knowledge and to identify the most important scientific questions expected to face the community during the interval 2013-2022. The survey has identified candidate missions that address the most important science questions and has conducted, through NASA sponsorship, concept studies to assess the cost of such missions as well as technology needs. The purpose of this paper is to provide an overview of the 2012 Solar System Planetary Science Decadal Survey study approach and missions that were studied for implementation in the upcoming decade. Final results of the decadal survey, including studies that were completed and the specific science, programmatic, and technology recommendations will be disclosed publically in the spring of 2011 and are not the subject of this paper.

Computer Vision for the Solar Dynamics Observatory (SDO)

NASA Astrophysics Data System (ADS)

Martens, P. C. H.; Attrill, G. D. R.; Davey, A. R.; Engell, A.; Farid, S.; Grigis, P. C.; Kasper, J.; Korreck, K.; Saar, S. H.; Savcheva, A.; Su, Y.; Testa, P.; Wills-Davey, M.; Bernasconi, P. N.; Raouafi, N.-E.; Delouille, V. A.; Hochedez, J. F.; Cirtain, J. W.; Deforest, C. E.; Angryk, R. A.; de Moortel, I.; Wiegelmann, T.; Georgoulis, M. K.; McAteer, R. T. J.; Timmons, R. P.

2012-01-01

In Fall 2008 NASA selected a large international consortium to produce a comprehensive automated feature-recognition system for the Solar Dynamics Observatory (SDO). The SDO data that we consider are all of the Atmospheric Imaging Assembly (AIA) images plus surface magnetic-field images from the Helioseismic and Magnetic Imager (HMI). We produce robust, very efficient, professionally coded software modules that can keep up with the SDO data stream and detect, trace, and analyze numerous phenomena, including flares, sigmoids, filaments, coronal dimmings, polarity inversion lines, sunspots, X-ray bright points, active regions, coronal holes, EIT waves, coronal mass ejections (CMEs), coronal oscillations, and jets. We also track the emergence and evolution of magnetic elements down to the smallest detectable features and will provide at least four full-disk, nonlinear, force-free magnetic field extrapolations per day. The detection of CMEs and filaments is accomplished with Solar and Heliospheric Observatory (SOHO)/ Large Angle and Spectrometric Coronagraph (LASCO) and ground-based Hα data, respectively. A completely new software element is a trainable feature-detection module based on a generalized image-classification algorithm. Such a trainable module can be used to find features that have not yet been discovered (as, for example, sigmoids were in the pre- Yohkoh era). Our codes will produce entries in the Heliophysics Events Knowledgebase (HEK) as well as produce complete catalogs for results that are too numerous for inclusion in the HEK, such as the X-ray bright-point metadata. This will permit users to locate data on individual events as well as carry out statistical studies on large numbers of events, using the interface provided by the Virtual Solar Observatory. The operations concept for our computer vision system is that the data will be analyzed in near real time as soon as they arrive at the SDO Joint Science Operations Center and have undergone basic processing. This will allow the system to produce timely space-weather alerts and to guide the selection and production of quicklook images and movies, in addition to its prime mission of enabling solar science. We briefly describe the complex and unique data-processing pipeline, consisting of the hardware and control software required to handle the SDO data stream and accommodate the computer-vision modules, which has been set up at the Lockheed-Martin Space Astrophysics Laboratory (LMSAL), with an identical copy at the Smithsonian Astrophysical Observatory (SAO).

2D layered insulator hexagonal boron nitride enabled surface passivation in dye sensitized solar cells.

PubMed

Shanmugam, Mariyappan; Jacobs-Gedrim, Robin; Durcan, Chris; Yu, Bin

2013-11-21

A two-dimensional layered insulator, hexagonal boron nitride (h-BN), is demonstrated as a new class of surface passivation materials in dye-sensitized solar cells (DSSCs) to reduce interfacial carrier recombination. We observe ~57% enhancement in the photo-conversion efficiency of the DSSC utilizing h-BN coated semiconductor TiO2 as compared with the device without surface passivation. The h-BN coated TiO2 is characterized by Raman spectroscopy to confirm the presence of highly crystalline, mixed monolayer/few-layer h-BN nanoflakes on the surface of TiO2. The passivation helps to minimize electron-hole recombination at the TiO2/dye/electrolyte interfaces. The DSSC with h-BN passivation exhibits significantly lower dark saturation current in the low forward bias region and higher saturation in the high forward bias region, respectively, suggesting that the interface quality is largely improved without impeding carrier transport at the material interface. The experimental results reveal that the emerging 2D layered insulator could be used for effective surface passivation in solar cell applications attributed to desirable material features such as high crystallinity and self-terminated/dangling-bond-free atomic planes as compared with high-k thin-film dielectrics.

Science Activities in Energy: Solar Energy II.

ERIC Educational Resources Information Center

Oak Ridge Associated Universities, TN.

Included in this science activities energy package are 14 activities related to solar energy for secondary students. Each activity is outlined on a single card and is introduced by a question such as: (1) how much solar heat comes from the sun? or (2) how many times do you have to run water through a flat-plate collector to get a 10 degree rise in…

The Solar Dynamics Observatory: Your On-Orbit Eye on the Sun

NASA Technical Reports Server (NTRS)

Pesnell, W. Dean

2011-01-01

The Solar Dynamics Observatory (SDO) was launched on February 11, 2010 into the partly cloudy skies above Cape Canaveral, Florida. Over the next month SDO moved into a 28 degree inclined geosynchronous orbit at the longitude of the ground station in New Mexico. SDO is the first Space Weather Mission in NASA's Living With a Star Program. SDO's main goal is to understand and predict those solar variations that influence life on Earth and our technological systems. The SDO science investigations will determine how the Sun's magnetic field is generated and structured, how this stored magnetic energy is released into the heliosphere as the solar wind, energetic particles, and variations in the solar irradiance. The SDO mission consists of three scientific investigations (AIA, EVE, and HMI), a spacecraft bus, and a dedicated Ka-band ground station to handle the 150 Mbps data flow. SDO continues a long tradition of NASA missions providing calibrated solar spectral irradiance data, in this case using multiple measurements of the irradiance and rocket underflights of the spacecraft. The other instruments on SDO will be used to explain and develop predictive models of the solar spectral irradiance in the extreme ultraviolet. Science teams at LMSAL, LASP, and Stanford are responsible for processing, analyzing, distributing, and archiving the science data. We will talk about the launch of SDO and describe the data and science it is providing to NASA.

Feasibility of Iodine and Bromine analysis in Genesis AloS collectors

NASA Astrophysics Data System (ADS)

Pravdivtseva, O.; Meshik, A.; Hohenberg, C. M.; Burnett, D. S.

2011-12-01

Comparison of solar, meteoritic and terrestrial elemental abundances provides understanding of the formation and evolution of the solar system. Yet, the majority of the solar abundances are based on meteoritic values [1-6]. As a continuation of our noble gas measurements of the Solar Wind (SW) [7] we attempted to evaluate the possibility of SW-iodine and SW-bromine analyses in the Genesis Solar Wind Aluminum on Sapphire collectors (AloS) using the conversions: 127I(n,γβ)128Xe, 79Br(n,γβ)80Kr and 81Br(n,γβ)82Kr. To estimate the extent of terrestrial halogen contamination in Genesis collectors, several flown fragments of AloS were submerged in methanol (for 1 hour and for 48 hours), rinsed, dried, sealed under vacuum in fused quartz ampoules and irradiated at the Missouri University Research Reactor receiving fluence ˜ 2E+19 thermal neutrons/cm2. Single step laser extraction using 1064 nm laser ablation of 0.7 cm2 area demonstrated clear signature of solar wind as indicated by 129Xe/132Xe = 1.045 ± 0.005, while 128Xe/132Xe = 1.01 ± 0.03 had a 12-fold excess compared to the solar value. Longer washing apparently reduces iodine contamination 4 times, implying that it is surface correlated. Krypton analysis showed 17% excess in 82Kr and 3-fold excess in 80Kr in agreement with their production ratio. A longer 48-hour washing reduced Br contamination 50 times. In order to better separate SW halogens from ubiquitous terrestrial contamination we employed a depth-profiling of AloS using 266 nm laser ablation. Laser beam power was increased in 12 consecutive steps using a combination of controlled defocusing and attenuation by a polarizing beamsplitter. Depth profile analysis revealed that terrestrial halogen contamination is present at the surface and at the interface between Al and sapphire substrate and is more pronounced for iodine, as indicated by 128Xe/132Xe ratio that is higher than atmospheric and solar wind values in all 12 rasters. While washing procedure reduced surface contamination, it did not affect iodine and bromine associated with the interface. Thus, cleaner Si-based Genesis collectors could be more suitable for SW halogen analyses. Our first results suggest that determination of solar iodine and bromine is potentially feasible, considering the possibility of analyzing larger collector areas irradiated with higher neutron fluence in order to improve counting statistics of the measurements. Supported by NASA grant NNX07AM76G. [1] Anders E. and Ebihara M. 1982. GCA 46:2363-2380. [2] Anders E. and Grevesse N. 1989. GCA 53:197-214. [3] Cameron A. G. W. 1968. in Origin and distribution of the elements (Ahrens L. H., ed.), Pergamon, Oxford:125-143. [4] Cameron A. G. W. 1973. Space Science Revues 15:121-146. [5] Suess H. E. and Urey H. C. 1956. Revisions of Modern Physics 28:53-74. [6] Lodders K. 2010. in: Principles and Perspectives in Cosmochemistry. 379-417. [7] Meshik A. et all. 2011. 74th Meteoritical Society Meeting, Abstract#5471.

Site selection feasibility for a solar energy system on the Fairbanks Federal Building

NASA Technical Reports Server (NTRS)

1978-01-01

A feasibility study was performed for the installation of a solar energy system on the Federal Building in Fairbanks, Alaska, a multifloor office building with an enclosed parking garge. The study consisted of determining the collectable solar energy at the Fairbanks site on a monthly basis and comparing this to the monthly building heating load. Potential conventional fuel savings were calculated on a monthly basis and the overall economics of the solar system applications were considered. Possible solar system design considerations, collector and other system installation details, interface of the solar system with the conventional HVAC systems, and possible control modes were all addressed. Conclusions, recommendations and study details are presented.

Elucidating the charge carrier separation and working mechanism of CH3NH3PbI(3-x)Cl(x) perovskite solar cells.

PubMed

Edri, Eran; Kirmayer, Saar; Mukhopadhyay, Sabyasachi; Gartsman, Konstantin; Hodes, Gary; Cahen, David

2014-03-11

Developments in organic-inorganic lead halide-based perovskite solar cells have been meteoric over the last 2 years, with small-area efficiencies surpassing 15%. We address the fundamental issue of how these cells work by applying a scanning electron microscopy-based technique to cell cross-sections. By mapping the variation in efficiency of charge separation and collection in the cross-sections, we show the presence of two prime high efficiency locations, one at/near the absorber/hole-blocking-layer, and the second at/near the absorber/electron-blocking-layer interfaces, with the former more pronounced. This 'twin-peaks' profile is characteristic of a p-i-n solar cell, with a layer of low-doped, high electronic quality semiconductor, between a p- and an n-layer. If the electron blocker is replaced by a gold contact, only a heterojunction at the absorber/hole-blocking interface remains.

Evolution of integrated panel structural design and interfaces for PV power plants

NASA Technical Reports Server (NTRS)

Arnett, J. C.; Anderson, A. J.; Robertson, R. E.

1983-01-01

The evolution of integrated photovoltaic (PV) panel design at ARCO Solar is discussed. Historically, framed PV modules of about 1 x 4-ft size were individually mounted in the field on fixed support structures and interconnected electrically with cables to build higher-power arrays. When ARCO Solar saw the opportunity in 1982 to marry its PV modules with state-of-the-art heliostat trackers developed by ARCO Power Systems, it became obvious that mounting individual modules was impractical. For this project, the framed modules were factory-assembled into panels and interconnected with cables before being mounted on the trackers. Since then, ARCO Solar made considerable progress and gained substantial experience in the design and fabrication of large PV panels. Constraints and criteria considered in these design activities included static and dynamic loads; assembly and transportation equipment and logistics, structural and electrical interfaces, and safety and grounding concerns.

Efficient direct solar-to-hydrogen conversion by in situ interface transformation of a tandem structure

NASA Astrophysics Data System (ADS)

May, Matthias M.; Lewerenz, Hans-Joachim; Lackner, David; Dimroth, Frank; Hannappel, Thomas

2015-09-01

Photosynthesis is nature's route to convert intermittent solar irradiation into storable energy, while its use for an industrial energy supply is impaired by low efficiency. Artificial photosynthesis provides a promising alternative for efficient robust carbon-neutral renewable energy generation. The approach of direct hydrogen generation by photoelectrochemical water splitting utilizes customized tandem absorber structures to mimic the Z-scheme of natural photosynthesis. Here a combined chemical surface transformation of a tandem structure and catalyst deposition at ambient temperature yields photocurrents approaching the theoretical limit of the absorber and results in a solar-to-hydrogen efficiency of 14%. The potentiostatically assisted photoelectrode efficiency is 17%. Present benchmarks for integrated systems are clearly exceeded. Details of the in situ interface transformation, the electronic improvement and chemical passivation are presented. The surface functionalization procedure is widely applicable and can be precisely controlled, allowing further developments of high-efficiency robust hydrogen generators.

Enhanced Solar Cell Conversion Efficiency of InGaN/GaN Multiple Quantum Wells by Piezo-Phototronic Effect.

PubMed

Jiang, Chunyan; Jing, Liang; Huang, Xin; Liu, Mengmeng; Du, Chunhua; Liu, Ting; Pu, Xiong; Hu, Weiguo; Wang, Zhong Lin

2017-09-26

The piezo-phototronic effect is the tuning of piezoelectric polarization charges at the interface to largely enhance the efficiency of optoelectronic processes related to carrier separation or recombination. Here, we demonstrated the enhanced short-circuit current density and the conversion efficiency of InGaN/GaN multiple quantum well solar cells with an external stress applied on the device. The external-stress-induced piezoelectric charges generated at the interfaces of InGaN and GaN compensate the piezoelectric charges induced by lattice mismatch stress in the InGaN wells. The energy band realignment is calculated with a self-consistent numerical model to clarify the enhancement mechanism of optical-generated carriers. This research not only theoretically and experimentally proves the piezo-phototronic effect modulated the quantum photovoltaic device but also provides a great promise to maximize the use of solar energy in the current energy revolution.

Low-cost zinc-plated photoanode for fabric-type dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Kong, Lingfeng; Bao, Yunna; Guo, Wanwan; Cheng, Li; Du, Jun; Liu, Renlong; Wang, Yundong; Fan, Xing; Tao, Changyuan

2016-02-01

Fabric-type flexible solar cells have been recently proposed as a very promising power source for wearable electronics. To increase the photocurrent of fabric-type flexible solar cells, low-cost zinc-plated wire and mesh photoanodes are assembled for the first time through a mild wet process. Given the protection of the compact protection layer, the DSSC device could benefit from the low work function of Zn and self-repairing behavior on the Zn/ZnO interface. An evident current increase by ∼6 mA/cm2 could be observed after coating a layer of metal Zn on various metal substrates, such as traditional stainless steel wire. Given the self-repairing behavior on Zn/ZnO interface, the Zn layer can help to improve the interfacial carrier transfer, leading to better photovoltaic performance, for both liquid-type and solid-type cells.

Efficient direct solar-to-hydrogen conversion by in situ interface transformation of a tandem structure

PubMed Central

May, Matthias M.; Lewerenz, Hans-Joachim; Lackner, David; Dimroth, Frank; Hannappel, Thomas

2015-01-01

Photosynthesis is nature's route to convert intermittent solar irradiation into storable energy, while its use for an industrial energy supply is impaired by low efficiency. Artificial photosynthesis provides a promising alternative for efficient robust carbon-neutral renewable energy generation. The approach of direct hydrogen generation by photoelectrochemical water splitting utilizes customized tandem absorber structures to mimic the Z-scheme of natural photosynthesis. Here a combined chemical surface transformation of a tandem structure and catalyst deposition at ambient temperature yields photocurrents approaching the theoretical limit of the absorber and results in a solar-to-hydrogen efficiency of 14%. The potentiostatically assisted photoelectrode efficiency is 17%. Present benchmarks for integrated systems are clearly exceeded. Details of the in situ interface transformation, the electronic improvement and chemical passivation are presented. The surface functionalization procedure is widely applicable and can be precisely controlled, allowing further developments of high-efficiency robust hydrogen generators. PMID:26369620

Scientific Benefits of Space Science Models Archiving at Community Coordinated Modeling Center

NASA Technical Reports Server (NTRS)

Kuznetsova, Maria M.; Berrios, David; Chulaki, Anna; Hesse, Michael; MacNeice, Peter J.; Maddox, Marlo M.; Pulkkinen, Antti; Rastaetter, Lutz; Taktakishvili, Aleksandre

2009-01-01

The Community Coordinated Modeling Center (CCMC) hosts a set of state-of-the-art space science models ranging from the solar atmosphere to the Earth's upper atmosphere. CCMC provides a web-based Run-on-Request system, by which the interested scientist can request simulations for a broad range of space science problems. To allow the models to be driven by data relevant to particular events CCMC developed a tool that automatically downloads data from data archives and transform them to required formats. CCMC also provides a tailored web-based visualization interface for the model output, as well as the capability to download the simulation output in portable format. CCMC offers a variety of visualization and output analysis tools to aid scientists in interpretation of simulation results. During eight years since the Run-on-request system became available the CCMC archived the results of almost 3000 runs that are covering significant space weather events and time intervals of interest identified by the community. The simulation results archived at CCMC also include a library of general purpose runs with modeled conditions that are used for education and research. Archiving results of simulations performed in support of several Modeling Challenges helps to evaluate the progress in space weather modeling over time. We will highlight the scientific benefits of CCMC space science model archive and discuss plans for further development of advanced methods to interact with simulation results.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leonard, E.; Arzel, L.; Tomassini, M.

Thinning the absorber layer is one of the possibilities envisaged to further decrease the production costs of Cu(In,Ga)Se{sub 2} (CIGSe) thin films solar cell technology. In the present study, the electronic transport in submicron CIGSe-based devices has been investigated and compared to that of standard devices. It is observed that when the absorber is around 0.5 μm-thick, tunnelling enhanced interface recombination dominates, which harms cells energy conversion efficiency. It is also shown that by varying either the properties of the Mo back contact or the characteristics of 3-stage growth processing, one can shift the dominating recombination mechanism from interface to spacemore » charge region and thereby improve the cells efficiency. Discussions on these experimental facts led to the conclusions that 3-stage process implies the formation of a CIGSe/CIGSe homo-interface, whose location as well as properties rule the device operation; its influence is enhanced in submicron CIGSe based solar cells.« less

Optimized interface and recrystallized grains by CsBr treatment for enhanced photovoltaic performance of perovskite solar cells

NASA Astrophysics Data System (ADS)

Liu, Li; Su, Pengyu; Yao, Huizhen; Wang, Jun; Fu, Wuyou; Liu, Xizhe; Yang, Haibin

2018-06-01

Doping, interface optimization and recrystallization are effective approaches for fabricating high performance perovskite solar cells (PSCs). In our work, simple CsBr treatment is introduced to improve the performance of TiO2 nanorods-based PSCs. Both Cs+ and Br- are doped into CH3NH3PbI3 simultaneously, as well as optimizes the interface between perovskite and hole-transporting material (HTM). In addition, the perovskite grains are recrystallized through this method. Finally, a power conversion efficiency (PCE) of 16.02% with 0.72 in fill factor (FF) and 1.08 in open circuit voltage (VOC) is obtained through CsBr treatment, which is 19.91% higher than that of untreated devices (13.36% with 0.65 in FF and 1.02 in VOC). Furthermore, the power output maintains ∼14% after 3500 h under the humidity within 15% at room temperature.

Direct Mapping of Band Positions in Doped and Undoped Hematite during Photoelectrochemical Water Splitting

DOE PAGES

Shavorskiy, Andrey; Ye, Xiaofei; Karslgolu, Osman; ...

2017-10-30

Photoelectrochemical water splitting is a promising pathway for the direct conversion of renewable solar energy to easy to store and use chemical energy. The performance of a photoelectrochemical device is determined in large part by the heterogeneous interface between the photoanode and the electrolyte, which we here characterize directly under operating conditions using interface-specific probes. Utilizing X-ray photoelectron spectroscopy as a noncontact probe of local electrical potentials, we demonstrate direct measurements of the band alignment at the semiconductor/electrolyte interface of an operating hematite/KOH photoelectrochemical cell as a function of solar illumination, applied potential, and doping. Here, we provide evidence formore » the absence of in-gap states in this system, which is contrary to previous measurements using indirect methods, and give a comprehensive description of shifts in the band positions and limiting processes during the photoelectrochemical reaction.« less

Enhancing students' science literacy using solar cell learning multimedia containing science and nano technology

NASA Astrophysics Data System (ADS)

Eliyawati, Sunarya, Yayan; Mudzakir, Ahmad

2017-05-01

This research attempts to enhance students' science literacy in the aspects of students' science content, application context, process, and students' attitude using solar cell learning multimedia containing science and nano technology. The quasi-experimental method with pre-post test design was used to achieve these objectives. Seventy-two students of class XII at a high school were employed as research's subject. Thirty-six students were in control class and another thirty-six were in experiment class. Variance test (t-test) was performed on the average level of 95% to identify the differences of students' science literacy in both classes. As the result, there were significant different of learning outcomes between experiment class and control class. Almost half of students (41.67%) in experiment class are categorized as high. Therefore, the learning using solar cell learning multimedia can improve students' science literacy, especially in the students' science content, application context, and process aspects with n-gain(%) 59.19 (medium), 63.04 (medium), and 52.98 (medium). This study can be used to develop learning multimedia in other science context.

Investigation of test methods, material properties, and processes for solar cell encapsulants

NASA Technical Reports Server (NTRS)

Willis, P. B.

1981-01-01

Encapsulant materials and processes for the production of cost-effective, long-life solar cell modules were investigated. The following areas were explored: (1) soil resistant surface treatment; (2) corrosion protecting coatings from mild steel substrates; (3) primers for bonding module interfaces; and (4) RS/4 accelerated aging of candidate encapsulation compounds

Solar excitation of CdS/Cu2S photovoltaic cells

NASA Technical Reports Server (NTRS)

Boer, K. W.

1976-01-01

Solar radiation of five typical clear weather days and under a variety of conditions is used to determine the spectral distribution of the photonflux at different planes of a CdS/Cu2S solar cell. The fractions of reflected and absorbed flux are determined at each of the relevant interfaces and active volume elements of the solar cell. The density of absorbed photons is given in respect to spectral and spatial distribution. The variance of the obtained distribution, with changes in insolation and absorption spectra of the active solar cell layers, is indicated. A catalog of typical examples is given in the appendix.

The Formation of CIRs at Stream-Stream Interfaces and Resultant Geomagnetic Activity

NASA Technical Reports Server (NTRS)

Richardson, I. G.

2005-01-01

Corotating interaction regions (CIRs) are regions of compressed plasma formed at the leading edges of corotating high-speed solar wind streams originating in coronal holes as they interact with the preceding slow solar wind. Although particularly prominent features of the solar wind during the declining and minimum phases of the 11-year solar cycle, they may also be present at times of higher solar activity. We describe how CIRs are formed, and their geomagnetic effects, which principally result from brief southward interplanetary magnetic field excursions associated with Alfven waves. Seasonal and long-term variations in these effects are briefly discussed.

Energy-level alignment and open-circuit voltage at graphene/polymer interfaces: theory and experiment

NASA Astrophysics Data System (ADS)

Noori, Keian; Konios, Dimitrios; Stylianakis, Minas M.; Kymakis, Emmanuel; Giustino, Feliciano

2016-03-01

Functionalized graphene promises to become a key component of novel solar cell architectures, owing to its versatile ability to act either as transparent conductor, electron acceptor, or buffer layer. In spite of this promise, the solar energy conversion efficiency of graphene-based devices falls short of the performance of competing solution-processable photovoltaic technologies. Here we address the question of the maximum achievable open-circuit voltage of all-organic graphene: polymer solar cells using a combined theoretical/experimental approach, going from the atomic scale level to the device level. Our calculations on very large atomistic models of the graphene/polymer interface indicate that the ideal open-circuit voltage approaches one volt, and that epoxide functional groups can have a dramatic effect on the photovoltage. Our predictions are confirmed by direct measurements on complete devices where we control the concentration of functional groups via chemical reduction. Our findings indicate that the selective removal of epoxide groups and the use of ultradisperse polymers are key to achieving graphene solar cells with improved energy conversion efficiency.

Analysis of the PEDOT:PSS/Si nanowire hybrid solar cell with a tail state model

NASA Astrophysics Data System (ADS)

Ho, Kuan-Ying; Li, Chi-Kang; Syu, Hong-Jhang; Lai, Yi; Lin, Ching-Fuh; Wu, Yuh-Renn

2016-12-01

In this paper, the electrical properties of the poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS)/silicon nanowire hybrid solar cell have been analyzed and an optimized structure is proposed. In addition, the planar PEDOT:PSS/c-Si hybrid solar cell is also modeled for comparison. We first developed a simulation software which is capable of modeling organic/inorganic hybrid solar cells by including Gaussian shape density of states into Poisson and drift-diffusion solver to present the tail states and trap states in the organic material. Therefore, the model can handle carrier transport, generation, and recombination in both organic and inorganic materials. Our results show that at the applied voltage near open-circuit voltage (Voc), the recombination rate becomes much higher at the PEDOT:PSS/Si interface region, which limits the fill factor and Voc. Hence, a modified structure with a p-type amorphous silicon (a-Si) layer attached on the interface of Si layer and an n+-type Si layer inserted near the bottom contact are proposed. The highest conversion efficiency of 16.10% can be achieved if both structures are applied.

Investigations on the charge transfer mechanism at donor/acceptor interfaces in the quest for descriptors of organic solar cell performance.

PubMed

Muraoka, Azusa; Fujii, Mikiya; Mishima, Kenji; Matsunaga, Hiroki; Benten, Hiroaki; Ohkita, Hideo; Ito, Shinzaburo; Yamashita, Koichi

2018-05-07

Herein, we theoretically and experimentally investigated the mechanisms of charge separation processes of organic thin-film solar cells. PTB7, PTB1, and PTBF2 have been chosen as donors and PC 71 BM has been chosen as an acceptor considering that effective charge generation depends on the difference between the material combinations. Experimental results of transient absorption spectroscopy show that the hot process is a key step for determining external quantum efficiency (EQE) in these systems. From the quantum chemistry calculations, it has been found that EQE tends to increase as the transferred charge, charge transfer distance, and variation of dipole moments between the ground and excited states of the donor/acceptor complexes increase; this indicates that these physical quantities are a good descriptor to assess the donor-acceptor charge transfer quality contributing to the solar cell performance. We propose that designing donor/acceptor interfaces with large values of charge transfer distance and variation of dipole moments of the donor/acceptor complexes is a prerequisite for developing high-efficiency polymer/PCBM solar cells.

High-Performance Ultrathin Organic-Inorganic Hybrid Silicon Solar Cells via Solution-Processed Interface Modification.

PubMed

Zhang, Jie; Zhang, Yinan; Song, Tao; Shen, Xinlei; Yu, Xuegong; Lee, Shuit-Tong; Sun, Baoquan; Jia, Baohua

2017-07-05

Organic-inorganic hybrid solar cells based on n-type crystalline silicon and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) exhibited promising efficiency along with a low-cost fabrication process. In this work, ultrathin flexible silicon substrates, with a thickness as low as tens of micrometers, were employed to fabricate hybrid solar cells to reduce the use of silicon materials. To improve the light-trapping ability, nanostructures were built on the thin silicon substrates by a metal-assisted chemical etching method (MACE). However, nanostructured silicon resulted in a large amount of surface-defect states, causing detrimental charge recombination. Here, the surface was smoothed by solution-processed chemical treatment to reduce the surface/volume ratio of nanostructured silicon. Surface-charge recombination was dramatically suppressed after surface modification with a chemical, associated with improved minority charge-carrier lifetime. As a result, a power conversion efficiency of 9.1% was achieved in the flexible hybrid silicon solar cells, with a substrate thickness as low as ∼14 μm, indicating that interface engineering was essential to improve the hybrid junction quality and photovoltaic characteristics of the hybrid devices.

The solar optical telescope

NASA Technical Reports Server (NTRS)

1990-01-01

Objectives of the Solar Optical Telescope are to study the physics of the Sun on the scale at which many of the important physical processes occur and to attain a resolution of 73km on the Sun or 0.1 arc seconds of angular resolution. Topics discussed in this overview of the Solar Optical Telescope include: why is the Solar Optical Telescope needed; current picture of the Sun's atmosphere and convection zone; scientific problems for the Solar Optical Telescope; a description of the telescope; the facility - science management, contamination control, and accessibility to the instruments; the scientific instruments - a coordinated instrument package for unlocking the Sun's secrets; parameters of the coordinated instrument package; science operations from the Space Shuttle; and the dynamic solar atmosphere.

Ferroelectric Thin-Film Capacitors As Ultraviolet Detectors

NASA Technical Reports Server (NTRS)

Thakoor, Sarita

1995-01-01

Advantages include rapid response, solar blindness, and relative invulnerability to ionizing radiation. Ferroelectric capacitor made to function as photovoltaic detector of ultraviolet photons by making one of its electrodes semitransparent. Photovoltaic effect exploited more fully by making Schottky barrier at illuminated semitransparent-electrode/ferroelectric interface taller than Schottky barrier at other electrode/ferroelectric interface.

Elizabeth Brown and Citizen Science in the Late 1800s (poster)

NASA Astrophysics Data System (ADS)

Larsen, K.

2013-06-01

(Abstract only) While "Citizen Science" projects are sometimes thought of as a recent permutation of the professional-amateur relationship in science, the AAVSO is an example of an organization that has been encouraging such participation for over a century. Although the AAVSO's Solar Observing Program dates back only to 1944, AAVSO members had been submitting sunspot counts to other agencies long before this time. Other countries also have a long history of collecting valuable sunspot observations. For example, prior to the AAVSO's founding in 1911, British amateurs had been collecting solar data in organizations such as the British Astronomical Association (BAA) and Liverpool Astronomical Society (LAS) since the 1880s. British amateur astronomer Elizabeth Brown served as Solar Section Director of both the BAA and the LAS, and played an important role in promoting participation in citizen science projects, not only in solar observing, but in other astronomical and meteorological projects as well. This poster will summarize this work and argue that Brown's contributions should be more widely known and studied in modern citizen science project circles.

Recombination phenomena in high efficiency silicon solar cells

NASA Technical Reports Server (NTRS)

Sah, C. T.

1985-01-01

The dominant recombination phenomena which limit the highest efficiency attainable in silicon solar cells under terrestrial sunlight are reviewed. The ultimate achievable efficiency is limited by the two intrinsic recombination mechanisms, the interband Auger recombination and interband Radiative recombination, both of which occur in the entire cell body but principally in the base layer. It is suggested that an optimum (26%) cell design is one with lowly doped 50 to 100 micron thick base, a perfect BSF, and zero extrinsic recombination such as the thermal mechanism at recombination centers the Shockley-Read-Hall process (SRH) in the bulk, on the surface and at the interfaces. The importance of recombination at the interfaces of a high-efficiency cell is demonstrated by the ohmic contact on the back surface whose interface recombination velocity is infinite. The importance of surface and interface recombination is demonstrated by representing the auger and radiative recombination losses by effective recombination velocities. It is demonstrated that the three highest efficiency cells may all be limited by the SRH recombination losses at recombination centers in the base layer.

Two-step photon up-conversion solar cells

PubMed Central

Asahi, Shigeo; Teranishi, Haruyuki; Kusaki, Kazuki; Kaizu, Toshiyuki; Kita, Takashi

2017-01-01

Reducing the transmission loss for below-gap photons is a straightforward way to break the limit of the energy-conversion efficiency of solar cells (SCs). The up-conversion of below-gap photons is very promising for generating additional photocurrent. Here we propose a two-step photon up-conversion SC with a hetero-interface comprising different bandgaps of Al0.3Ga0.7As and GaAs. The below-gap photons for Al0.3Ga0.7As excite GaAs and generate electrons at the hetero-interface. The accumulated electrons at the hetero-interface are pumped upwards into the Al0.3Ga0.7As barrier by below-gap photons for GaAs. Efficient two-step photon up-conversion is achieved by introducing InAs quantum dots at the hetero-interface. We observe not only a dramatic increase in the additional photocurrent, which exceeds the reported values by approximately two orders of magnitude, but also an increase in the photovoltage. These results suggest that the two-step photon up-conversion SC has a high potential for implementation in the next-generation high-efficiency SCs. PMID:28382945

Fabrication of CuInS2-sensitized solar cells via an improved SILAR process and its interface electron recombination.

PubMed

Xu, Xueqing; Wan, Qingcui; Luan, Chunyan; Mei, Fengjiao; Zhao, Qian; An, Ping; Liang, Zhurong; Xu, Gang; Zapien, Juan Antonio

2013-11-13

Tetragonal CuInS2 (CIS) has been successfully deposited onto mesoporous TiO2 films by in-sequence growth of InxS and CuyS via a successive ionic layer absorption and reaction (SILAR) process and postdeposition annealing in sulfur ambiance. X-ray diffraction and Raman measurements showed that the obtained tetragonal CIS consisted of a chalcopyrite phase and Cu-Au ordering, which related with the antisite defect states. For a fixed Cu-S deposition cycle, an interface layer of β-In2S3 formed at the TiO2/CIS interface with suitable excess deposition of In-S. In the meantime, the content of the Cu-Au ordering phase decreased to a reasonable level. These facts resulted in the retardance of electron recombination in the cells, which is proposed to be dominated by electron transfer from the conduction band of TiO2 to the unoccupied defect states in CIS via exponentially distributed surface states. As a result, a relatively high efficiency of ~0.92% (V(oc) = 0.35 V, J(sc) = 8.49 mA cm(-2), and FF = 0.31) has been obtained. Last, but not least, with an overloading of the sensitizers, a decrease in the interface area between the sensitized TiO2 and electrolytes resulted in deceleration of hole extraction from CIS to the electrolytes, leading to a decrease in the fill factor of the solar cells. It is indicated that the unoccupied states in CIS with energy levels below EF0 of the TiO2 films play an important role in the interface electron recombination at low potentials and has a great influence on the fill factor of the solar cells.

MHD Wave Propagation at the Interface Between Solar Chromosphere and Corona

NASA Astrophysics Data System (ADS)

Huang, Y.; Song, P.; Vasyliunas, V. M.

2017-12-01

We study the electromagnetic and momentum constraints at the solar transition region which is a sharp layer interfacing between the solar chromosphere and corona. When mass transfer between the two domains is neglected, the transition region can be treated as a contact discontinuity across which the magnetic flux is conserved and the total forces are balanced. We consider an Alfvénic perturbation that propagates along the magnetic field incident onto the interface from one side. In order to satisfy the boundary conditions at the transition region, only part of the incident energy flux is transmitted through and the rest is reflected. Taking into account the highly anisotropic propagation of waves in magnetized plasmas, we generalize the law of reflection and specify Snell's law for each of the three wave MHD modes: incompressible Alfvén mode and compressible fast and slow modes. Unlike conventional optical systems, the interface between two magnetized plasmas is not rigid but can be deformed by the waves, allowing momentum and energy to be transferred by compression. With compressible modes included, the Fresnel conditions need substantial modification. We derive Fresnel conditions, reflectivities and transmittances, and mode conversion for incident waves propagating along the background magnetic field. The results are well organized when the incident perturbation is decomposed into components in and normal to the incident plane (containing the background magnetic field and the normal direction of the interface). For a perturbation normal to the incident plane, both transmitted and reflected perturbations are incompressible Alfvén mode waves. For a perturbation in the incident plane, they can be compressible slow and fast mode waves which may produce ripples on the transition region.

The Lyman-alpha Solar Telescope for the ASO-S

NASA Astrophysics Data System (ADS)

Li, Hui

2015-08-01

The Lyman-alpha Solar Telescope (LST) is one of the payloads for the proposed Space-Borne Advanced Solar Observatory (ASO-S). LST consists of a Solar Disk Imager (SDI) with a field-of-view (FOV) of 1.2 Rsun, a Solar Corona Imager (SCI) with an FOV of 1.1 - 2.5 Rsun, and a full-disk White-light Solar Telescope (WST) with an FOV of 1.2 Rsun, which also serves as the guiding telescope. The SCI is designed to work at the Lyman-alpha waveband and white-light, while the SDI will work at the Lyman-alpha waveband only. The WST works both in visible (for guide) and ultraviolet (for science) white-light. The LST will observe the Sun from disk-center up to 2.5 solar radii for both solar flares and coronal mass ejections. In this presentation, I will give an introduction to LST, including scientific objectives, science requirement, instrument design and current status.

Solar cycle dynamics of solar, magnetospheric, and heliospheric particles, and long-term atmospheric coupling: SAMPLEX

NASA Technical Reports Server (NTRS)

Mason, G. M. (Principal Investigator); Hamilton, D. C.; Blake, J. B.; Mewaldt, R. A.; Stone, E. C.; Baker, D. N.; VonRosenvinge, T. T.; Callis, L. B.; Klecker, B.; Hovestadt, D.;

KSC-2013-2643

NASA Image and Video Library

2013-06-10

VANDENBERG AFB – The Orbital Sciences Pegasus XL rocket that will lift the solar observatory into orbit in June is seen after the payload fairing was connected over NASA's IRIS spacecraft. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch on a Pegasus XL rocket. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Tony Vauclin

KSC-2013-2494

NASA Image and Video Library

2013-05-29

VANDENBERG AFB, Calif. – Engineers unwrap NASA's IRIS spacecraft after its connection to the nose of an Orbital Sciences Pegasus XL rocket that will lift the solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch on a Pegasus XL rocket. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Randy Beaudoin

KSC-2013-2493

NASA Image and Video Library

2013-05-29

VANDENBERG AFB, Calif. – Engineers unwrap NASA's IRIS spacecraft after its connection to the nose of an Orbital Sciences Pegasus XL rocket that will lift the solar observatory into orbit in June. The work is taking place in a hangar at Vandenberg Air Force Base where IRIS, short for Interface Region Imaging Spectrograph, is being prepared for launch on a Pegasus XL rocket. Scheduled for launch from Vandenberg June 26, IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun’s corona using spectrometry and imaging. IRIS fills a crucial gap in our ability to advance studies of the sun-to-Earth connection by tracing the flow of energy and plasma through the foundation of the corona and the region around the sun known as the heliosphere. Photo credit: NASA/Randy Beaudoin

The LatHyS database for planetary plasma environment investigations: Overview and a case study of data/model comparisons

NASA Astrophysics Data System (ADS)

Modolo, R.; Hess, S.; Génot, V.; Leclercq, L.; Leblanc, F.; Chaufray, J.-Y.; Weill, P.; Gangloff, M.; Fedorov, A.; Budnik, E.; Bouchemit, M.; Steckiewicz, M.; André, N.; Beigbeder, L.; Popescu, D.; Toniutti, J.-P.; Al-Ubaidi, T.; Khodachenko, M.; Brain, D.; Curry, S.; Jakosky, B.; Holmström, M.

2018-01-01

We present the Latmos Hybrid Simulation (LatHyS) database, which is dedicated to the investigations of planetary plasma environment. Simulation results of several planetary objects (Mars, Mercury, Ganymede) are available in an online catalogue. The full description of the simulations and their results is compliant with a data model developped in the framework of the FP7 IMPEx project. The catalogue is interfaced with VO-visualization tools such AMDA, 3DView, TOPCAT, CLweb or the IMPEx portal. Web services ensure the possibilities of accessing and extracting simulated quantities/data. We illustrate the interoperability between the simulation database and VO-tools using a detailed science case that focuses on a three-dimensional representation of the solar wind interaction with the Martian upper atmosphere, combining MAVEN and Mars Express observations and simulation results.

Employing Lead Thiocyanate Additive to Reduce the Hysteresis and Boost the Fill Factor of Planar Perovskite Solar Cells.

PubMed

Ke, Weijun; Xiao, Chuanxiao; Wang, Changlei; Saparov, Bayrammurad; Duan, Hsin-Sheng; Zhao, Dewei; Xiao, Zewen; Schulz, Philip; Harvey, Steven P; Liao, Weiqiang; Meng, Weiwei; Yu, Yue; Cimaroli, Alexander J; Jiang, Chun-Sheng; Zhu, Kai; Al-Jassim, Mowafak; Fang, Guojia; Mitzi, David B; Yan, Yanfa

2016-07-01

Lead thiocyanate in the perovskite precursor can increase the grain size of a perovskite thin film and reduce the conductivity of the grain boundaries, leading to perovskite solar cells with reduced hysteresis and enhanced fill factor. A planar perovskite solar cell with grain boundary and interface passivation achieves a steady-state efficiency of 18.42%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simulation optimizing of n-type HIT solar cells with AFORS-HET

NASA Astrophysics Data System (ADS)

Yao, Yao; Xiao, Shaoqing; Zhang, Xiumei; Gu, Xiaofeng

2017-07-01

This paper presents a study of heterojunction with intrinsic thin layer (HIT) solar cells based on n-type silicon substrates by a simulation software AFORS-HET. We have studied the influence of thickness, band gap of intrinsic layer and defect densities of every interface. Details in mechanisms are elaborated as well. The results show that the optimized efficiency reaches more than 23% which may give proper suggestions to practical preparation for HIT solar cells industry.

Air Brayton Solar Receiver, phase 1

NASA Technical Reports Server (NTRS)

Zimmerman, D. K.

1979-01-01

A six month analysis and conceptual design study of an open cycle Air Brayton Solar Receiver (ABSR) for use on a tracking, parabolic solar concentrator are discussed. The ABSR, which includes a buffer storage system, is designed to provide inlet air to a power conversion unit. Parametric analyses, conceptual design, interface requirements, and production cost estimates are described. The design features were optimized to yield a zero maintenance, low cost, high efficiency concept that will provide a 30 year operational life.

Loss mechanisms in high-efficiency solar cells: Study of material properties and high-efficiency solar-cell performance on material composition: Project tasks

NASA Technical Reports Server (NTRS)

Sah, C. T.

1985-01-01

Loss mechanisms in high-efficiency solar cells were discussed. Fundamental limitations and practical solutions were stressed. Present cell efficiency is limited by many recombination sites: emitter, base, contacts, and oxide/silicon interface. Use of polysilicon passivation was suggested. After reduction of these losses, a 25% efficient cell could be built. A floating emitter cell design was shown that had the potential of low recombination losses.

Exploring the Solar System Activities Outline: Hands-On Planetary Science for Formal Education K-14 and Informal Settings

NASA Technical Reports Server (NTRS)

Allen, J. S.; Tobola, K. W.; Lindstrom, M. L.

2003-01-01

Activities by NASA scientists and teachers focus on integrating Planetary Science activities with existing Earth science, math, and language arts curriculum. The wealth of activities that highlight missions and research pertaining to the exploring the solar system allows educators to choose activities that fit a particular concept or theme within their curriculum. Most of the activities use simple, inexpensive techniques that help students understand the how and why of what scientists are learning about comets, asteroids, meteorites, moons and planets. With these NASA developed activities students experience recent mission information about our solar system such as Mars geology and the search for life using Mars meteorites and robotic data. The Johnson Space Center ARES Education team has compiled a variety of NASA solar system activities to produce an annotated thematic outline useful to classroom educators and informal educators as they teach space science. An important aspect of the outline annotation is that it highlights appropriate science content information and key science and math concepts so educators can easily identify activities that will enhance curriculum development. The outline contains URLs for the activities and NASA educator guides as well as links to NASA mission science and technology. In the informal setting educators can use solar system exploration activities to reinforce learning in association with thematic displays, planetarium programs, youth group gatherings, or community events. Within formal education at the primary level some of the activities are appropriately designed to excite interest and arouse curiosity. Middle school educators will find activities that enhance thematic science and encourage students to think about the scientific process of investigation. Some of the activities offered are appropriate for the upper levels of high school and early college in that they require students to use and analyze data.

Aluminium alloyed iron-silicide/silicon solar cells: A simple approach for low cost environmental-friendly photovoltaic technology.

PubMed

Kumar Dalapati, Goutam; Masudy-Panah, Saeid; Kumar, Avishek; Cheh Tan, Cheng; Ru Tan, Hui; Chi, Dongzhi

2015-12-03

This work demonstrates the fabrication of silicide/silicon based solar cell towards the development of low cost and environmental friendly photovoltaic technology. A heterostructure solar cells using metallic alpha phase (α-phase) aluminum alloyed iron silicide (FeSi(Al)) on n-type silicon is fabricated with an efficiency of 0.8%. The fabricated device has an open circuit voltage and fill-factor of 240 mV and 60%, respectively. Performance of the device was improved by about 7 fold to 5.1% through the interface engineering. The α-phase FeSi(Al)/silicon solar cell devices have promising photovoltaic characteristic with an open circuit voltage, short-circuit current and a fill factor (FF) of 425 mV, 18.5 mA/cm(2), and 64%, respectively. The significant improvement of α-phase FeSi(Al)/n-Si solar cells is due to the formation p(+-)n homojunction through the formation of re-grown crystalline silicon layer (~5-10 nm) at the silicide/silicon interface. Thickness of the regrown silicon layer is crucial for the silicide/silicon based photovoltaic devices. Performance of the α-FeSi(Al)/n-Si solar cells significantly depends on the thickness of α-FeSi(Al) layer and process temperature during the device fabrication. This study will open up new opportunities for the Si based photovoltaic technology using a simple, sustainable, and los cost method.

JHelioviewer: Open-Source Software for Discovery and Image Access in the Petabyte Age

NASA Astrophysics Data System (ADS)

Mueller, D.; Dimitoglou, G.; Garcia Ortiz, J.; Langenberg, M.; Nuhn, M.; Dau, A.; Pagel, S.; Schmidt, L.; Hughitt, V. K.; Ireland, J.; Fleck, B.

2011-12-01

The unprecedented torrent of data returned by the Solar Dynamics Observatory is both a blessing and a barrier: a blessing for making available data with significantly higher spatial and temporal resolution, but a barrier for scientists to access, browse and analyze them. With such staggering data volume, the data is accessible only from a few repositories and users have to deal with data sets effectively immobile and practically difficult to download. From a scientist's perspective this poses three challenges: accessing, browsing and finding interesting data while avoiding the proverbial search for a needle in a haystack. To address these challenges, we have developed JHelioviewer, an open-source visualization software that lets users browse large data volumes both as still images and movies. We did so by deploying an efficient image encoding, storage, and dissemination solution using the JPEG 2000 standard. This solution enables users to access remote images at different resolution levels as a single data stream. Users can view, manipulate, pan, zoom, and overlay JPEG 2000 compressed data quickly, without severe network bandwidth penalties. Besides viewing data, the browser provides third-party metadata and event catalog integration to quickly locate data of interest, as well as an interface to the Virtual Solar Observatory to download science-quality data. As part of the ESA/NASA Helioviewer Project, JHelioviewer offers intuitive ways to browse large amounts of heterogeneous data remotely and provides an extensible and customizable open-source platform for the scientific community. In addition, the easy-to-use graphical user interface enables the general public and educators to access, enjoy and reuse data from space missions without barriers.

ESA's Planetary Science Archive: Preserve and present reliable scientific data sets

NASA Astrophysics Data System (ADS)

Besse, S.; Vallat, C.; Barthelemy, M.; Coia, D.; Costa, M.; De Marchi, G.; Fraga, D.; Grotheer, E.; Heather, D.; Lim, T.; Martinez, S.; Arviset, C.; Barbarisi, I.; Docasal, R.; Macfarlane, A.; Rios, C.; Saiz, J.; Vallejo, F.

2018-01-01

The European Space Agency (ESA) Planetary Science Archive (PSA) is undergoing a significant refactoring of all its components to improve the services provided to the scientific community and the public. The PSA supports ESA's missions exploring the Solar System by archiving scientific peer-reviewed observations as well as engineering data sets. This includes the Giotto, SMART-1, Huygens, Venus Express, Mars Express, Rosetta, Exomars 2016, Exomars RSP, BepiColombo, and JUICE missions. The PSA is offering a newly designed graphical user interface which is simultaneously meant to maximize the interaction with scientific observations and also minimise the efforts needed to download these scientific observations. The PSA still offers the same services as before (i.e., FTP, documentation, helpdesk, etc.). In addition, it will support the two formats of the Planetary Data System (i.e., PDS3 and PDS4), as well as providing new ways for searching the data products with specific metadata and geometrical parameters. As well as enhanced services, the PSA will also provide new services to improve the visualisation of data products and scientific content (e.g., spectra, etc.). Together with improved access to the spacecraft engineering data sets, the PSA will provide easier access to scientific data products that will help to maximize the science return of ESA's space missions.

Goddard Space Flight Center solar array missions, requirements and directions

NASA Technical Reports Server (NTRS)

Gaddy, Edward; Day, John

1994-01-01

The Goddard Space Flight Center (GSFC) develops and operates a wide variety of spacecraft for conducting NASA's communications, space science, and earth science missions. Some are 'in house' spacecraft for which the GSFC builds the spacecraft and performs all solar array design, analysis, integration, and test. Others are 'out of house' spacecraft for which an aerospace contractor builds the spacecraft and develops the solar array under direction from GSFC. The experience of developing flight solar arrays for numerous GSFC 'in house' and 'out of house' spacecraft has resulted in an understanding of solar array requirements for many different applications. This presentation will review those solar array requirements that are common to most GSFC spacecraft. Solar array technologies will be discussed that are currently under development and that could be useful to future GSFC spacecraft.

Earth Science

NASA Image and Video Library

1990-10-24

Solar Vector Magnetograph is used to predict solar flares, and other activities associated with sun spots. This research provides new understanding about weather on the Earth, and solar-related conditions in orbit.

Interface design principles for high-performance organic semiconductor devices

DOE PAGES

Nie, Wanyi; Gupta, Gautam; Crone, Brian K.; ...

2015-03-23

Organic solar cells (OSCs) are a promising cost-effective candidate in next generation photovoltaic technology. However, a critical bottleneck for OSCs is the electron/hole recombination loss through charge transfer state at the interface, which greatly limits the power conversion efficiency. W. Nie, A. Mohite, and co-workers demonstrate a simple strategy of suppressing the recombination rate by inserting a spacer layer at the donor-acceptor interface, resulting in a dramatic increase in power conversion efficiency.

Computer Lab Tools for Science: An Analysis of Commercially Available Science Interfacing Software for Microcomputers. A Quarterly Report.

ERIC Educational Resources Information Center

Weaver, Dave

Science interfacing packages (also known as microcomputer-based laboratories or probeware) generally consist of a set of programs on disks, a user's manual, and hardware which includes one or more sensory devices. Together with a microcomputer they combine to make a powerful data acquisition and analysis tool. Packages are available for accurately…

Development of Experienced Science Teachers' Pedagogical Content Knowledge of Models of the Solar System and the Universe

ERIC Educational Resources Information Center

Henze, Ineke; van Driel, Jan H.; Verloop, Nico

2008-01-01

This paper investigates the developing pedagogical content knowledge (PCK) of nine experienced science teachers in their first few years of teaching a new science syllabus in the Dutch secondary education system. We aimed to identify the content and structure of the PCK for a specific topic in the new syllabus, "Models of the Solar System and…

Solar Energy. 7th and 8th Grade Agriculture Science Curriculum. Teacher Materials.

ERIC Educational Resources Information Center

Southern Illinois Univ., Carbondale. Dept. of Agricultural Education and Mechanization.

This curriculum guide, the third in a set of six, contains teacher and student materials for a unit on solar energy prepared as part of a seventh- and eighth-grade agricultural science curriculum that is integrated with science instruction. The guide contains the state goals and sample learning objectives for each goal for students in grades 8-10…

Wet Pretreatment-Induced Modification of Cu(In,Ga)Se2/Cd-Free ZnTiO Buffer Interface.

PubMed

Hwang, Suhwan; Larina, Liudmila; Lee, Hojin; Kim, Suncheul; Choi, Kyoung Soon; Jeon, Cheolho; Ahn, Byung Tae; Shin, Byungha

2018-06-20

We report a novel Cd-free ZnTiO buffer layer deposited by atomic layer deposition for Cu(In,Ga)Se 2 (CIGS) solar cells. Wet pretreatments of the CIGS absorbers with NH 4 OH, H 2 O, and/or aqueous solution of Cd 2+ ions were explored to improve the quality of the CIGS/ZnTiO interface, and their effects on the chemical state of the absorber and the final performance of Cd-free CIGS devices were investigated. X-ray photoelectron spectroscopy (XPS) analysis revealed that the aqueous solution etched away sodium compounds accumulated on the CIGS surface, which was found to be detrimental for solar cell operation. Wet treatment with NH 4 OH solution led to a reduced photocurrent, which was attributed to the thinning (or removal) of an ordered vacancy compound (OVC) layer on the CIGS surface as evidenced by an increased Cu XPS peak intensity after the NH 4 OH treatment. However, the addition of Cd 2+ ions to the NH 4 OH aqueous solution suppressed the etching of the OVC by NH 4 OH, explaining why such a negative effect of NH 4 OH is not present in the conventional chemical bath deposition of CdS. The band alignment at the CIGS/ZnTiO interface was quantified using XPS depth profile measurements. A small cliff-like conduction band offset of -0.11 eV was identified at the interface, which indicates room for further improvement of efficiency of the CIGS/ZnTiO solar cells once the band alignment is altered to a slight spike by inserting a passivation layer with a higher conduction band edge than ZnTiO. Combination of the small cliff conduction band offset at the interface, removal of the Na compound via water, and surface doping by Cd ions allowed the application of ZnTiO buffer to CIGS treated with Cd solutions, exhibiting an efficiency of 80% compared to that of a reference CIGS solar cell treated with the CdS.

Naval Research Laboratory Space Science Division Newsletter: 01/2007

DTIC Science & Technology

2007-04-20

Temperature Solar Flare Images 5. SECCHI HI-1B First Light 6. NRL SEAP Student Receives Intel Science Talent Search Semifinalist Award 7. NASA...achieved first light on 28 OCT 2006. EIS is observing emission lines produced by highly ionized elements in the solar corona and transition region of...measurements of the solar corona and CMEs as they propagate through the inner heliosphere. STEREO launched October 25, 2006, and achieved first light in early

Possibility of using sources of vacuum ultraviolet irradiation to solve problems of space material science

NASA Technical Reports Server (NTRS)

Verkhoutseva, E. T.; Yaremenko, E. I.

1974-01-01

An urgent problem in space materials science is simulating the interaction of vacuum ultraviolet (VUV) of solar emission with solids in space conditions, that is, producing a light source with a distribution that approximates the distribution of solar energy. Information is presented on the distribution of the energy flux of VUV of solar radiation. Requirements that must be satisfied by the VUV source used for space materials science are formulated, and a critical evaluation is given of the possibilities of using existing sources for space materials science. From this evaluation it was established that none of the sources of VUV satisfies the specific requirements imposed on the simulator of solar radiation. A solution to the problem was found to be in the development of a new type of source based on exciting a supersonic gas jet flowing into vacuum with a sense electron beam. A description of this gas-jet source, along with its spectral and operation characteristics, is presented.

Training Informal Educators Provides Leverage for Space Science Education and Public Outreach

NASA Technical Reports Server (NTRS)

Allen, J. S.; Tobola, K. W.; Betrue, R.

2004-01-01

How do we reach the public with the exciting story of Solar System Exploration? How do we encourage girls to think about careers in science, math, engineering and technology? Why should NASA scientists make an effort to reach the public and informal education settings to tell the Solar System Exploration story? These are questions that the Solar System Exploration Forum, a part of the NASA Office of Space Science Education (SSE) and Public Outreach network, has tackled over the past few years. The SSE Forum is a group of education teams and scientists who work to share the excitement of solar system exploration with colleagues, formal educators, and informal educators like museums and youth groups. One major area of the SSE Forum outreach supports the training of Girl Scouts of the USA (GS) leaders and trainers in a suite of activities that reflect NASA missions and science research. Youth groups like Girl Scouts structure their activities as informal education.

NASA Space Science Resource Catalog

NASA Astrophysics Data System (ADS)

Teays, T.

2000-05-01

The NASA Office of Space Science Resource Catalog provides a convenient online interface for finding space science products for use in classrooms, science museums, planetariums, and many other venues. Goals in developing this catalog are: (1) create a cataloging system for all NASA OSS education products, (2) develop a system for characterizing education products which is meaningful to a large clientele, (3) develop a mechanism for evaluating products, (4) provide a user-friendly interface to search and access the data, and (5) provide standardized metadata and interfaces to other cataloging and library systems. The first version of the catalog is being tested at the spring 2000 conventions of the National Science Teachers Association (NSTA) and the National Council of Teachers of Mathematics (NCTM) and will be released in summer 2000. The catalog may be viewed at the Origins Education Forum booth.

Science with the Expanded Owens Valley Solar Array

NASA Astrophysics Data System (ADS)

Nita, Gelu M.; Gary, Dale E.; Fleishman, Gregory D.; Chen, Bin; White, Stephen M.; Hurford, Gordon J.; McTiernan, James; Hickish, Jack; Yu, Sijie; Nelin, Kjell B.

2017-08-01

The Expanded Owens Valley Solar Array (EOVSA) is a solar-dedicated radio array that makes images and spectra of the full Sun on a daily basis. Our main science goals are to understand the basic physics of solar activity, such as how the Sun releases stored magnetic energy on timescales of seconds, and how that solar activity, in the form of solar flares and coronal mass ejections, influences the Earth and near-Earth space environment, through disruptions of communication and navigation systems, and effects on satellites and systems on the ground. The array, which is composed out of thirteen 2.1 m dishes and two 27 m dishes (used only for calibration), has a footprint of 1.1 km EW x 1.2 km NS and it is capable of producing, every second, microwave images at two polarizations and 500 science channels spanning the 1-18 GHz frequency range. Such ability to make multi-frequency images of the Sun in this broad range of frequencies, with a frequency dependent resolution ranging from ˜53” at 1 GHz to ˜3”at 18 GHz, is unique in the world. Here we present an overview of the EOVSA instrument and a first set of science-quality active region and solar flare images produced from data taken during April 2017.This research is supported by NSF grant AST-1615807 and NASA grant NNX14AK66G to New Jersey Institute of Technology.

STEREO Superior Solar Conjunction Mission Phase

NASA Technical Reports Server (NTRS)

Ossing, Daniel A.; Wilson, Daniel; Balon, Kevin; Hunt, Jack; Dudley, Owen; Chiu, George; Coulter, Timothy; Reese, Angel; Cox, Matthew; Srinivasan, Dipak;

The Virtual Solar-Terrestrial Observatory; access to and use of diverse solar and solar- terrestrial data.

NASA Astrophysics Data System (ADS)

Fox, P.; McGuinness, D.; Cinquini, L.; West, P.; Garcia, J.; Zednik, S.; Benedict, J.

2008-05-01

This presentation will demonstrate how users and other data providers can utilize the Virtual Solar-Terrestrial Observatory (VSTO) to find, access and use diverse data holdings from the disciplines of solar, solar-terrestrial and space physics. VSTO provides a web portal, web services and a native applications programming interface for various levels of users. Since these access methods are based on semantic web technologies and refer to the VSTO ontology, users also have the option of taking advantage of value added services when accessing and using the data. We present example of both conventional use of VSTO as well as the advanced semantics use. Finally, we present our future directions for VSTO and semantic data frameworks in general.

The Virtual Solar-Terrestrial Observatory; access to and use of diverse solar and solar-terrestrial data

NASA Astrophysics Data System (ADS)

Fox, P.

2007-05-01

This presentation will demonstrate how users and other data providers can utilize the Virtual Solar-Terrestrial Observatory (VSTO) to find, access and use diverse data holdings from the disciplines of solar, solar-terrestrial and space physics. VSTO provides a web portal, web services and a native applications programming interface for various levels of users. Since these access methods are based on semantic web technologies and refer to the VSTO ontology, users also have the option of taking advantage of value added services when accessing and using the data. We present example of both conventional use of VSTO as well as the advanced semantics use. Finally, we present our future directions for VSTO and semantic data frameworks in general.

The 2013 Clusters, Nanocrystals & Nanostructures Gordon Research Conference/Gordon Research Seminar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krauss, Todd D.

The fundamental properties of small particles and their potential for groundbreaking applications are among the most exciting areas of study in modern physics, chemistry, and materials science. The Clusters, Nanocrystals & Nanostructures Gordon ResearchConference and Gordon Research Seminar synthesize contributions from these inter-related fields that reflect the pivotal role of nano-particles at the interface between these disciplines. Size-dependent optical, electronic, magnetic and catalytic properties offer prospects for applications in many fields, and possible solutions for many of the grand challenges facing energy generation, consumption, delivery, and storage in the 21st century. The goal of the 2013 Clusters, Nanocrystals & Nanostructuresmore » Gordon Research Conference and Gordon Research Seminar is to continue the historical interdisciplinary tradition of this series and discuss the most recent advances, basic scientific questions, and emerging applications of clusters, nanocrystals, and nanostructures. The Clusters, Nanocrystals & Nanostructures GRC/GRS traditionally brings together the leading scientific groups that have made significant recent advances in one or more fundamental nanoscience or nanotechnology areas. Broad interests of the DOE BES and Solar Photochemistry Program addressed by this meeting include the areas of solar energy to fuels conversion, new photovoltaic systems, fundamental characterization of nanomaterials, magnetism, catalysis, and quantum physics. The vast majority of speakers and attendees will address either directly the topic of nanotechnology for photoinduced charge transfer, charge transport, and catalysis, or will have made significant contributions to related areas that will impact these fields indirectly. These topics have direct relevance to the mission of the DOE BES since it is this cutting-edge basic science that underpins our energy future.« less

SunPy: Python for Solar Physics

NASA Astrophysics Data System (ADS)

Bobra, M.; Inglis, A. R.; Mumford, S.; Christe, S.; Freij, N.; Hewett, R.; Ireland, J.; Martinez Oliveros, J. C.; Reardon, K.; Savage, S. L.; Shih, A. Y.; Pérez-Suárez, D.

2017-12-01

SunPy is a community-developed open-source software library for solar physics. It is written in Python, a free, cross-platform, general-purpose, high-level programming language which is being increasingly adopted throughout the scientific community. SunPy aims to provide the software for obtaining and analyzing solar and heliospheric data. This poster introduces a new major release, SunPy version 0.8. The first major new feature introduced is Fido, the new primary interface to download data. It provides a consistent and powerful search interface to all major data providers including the VSO and the JSOC, as well as individual data sources such as GOES XRS time series. It is also easy to add new data sources as they become available, i.e. DKIST. The second major new feature is the SunPy coordinate framework. This provides a powerful way of representing coordinates, allowing simple and intuitive conversion between coordinate systems and viewpoints of different instruments (i.e., Solar Orbiter and the Parker Solar Probe), including transformation to astrophysical frames like ICRS. Other new features including new timeseries capabilities with better support for concatenation and metadata, updated documentation and example gallery. SunPy is distributed through pip and conda and all of its code is publicly available (sunpy.org).

Improved amorphous/crystalline silicon interface passivation for heterojunction solar cells by low-temperature chemical vapor deposition and post-annealing treatment.

PubMed

Wang, Fengyou; Zhang, Xiaodan; Wang, Liguo; Jiang, Yuanjian; Wei, Changchun; Xu, Shengzhi; Zhao, Ying

2014-10-07

In this study, hydrogenated amorphous silicon (a-Si:H) thin films are deposited using a radio-frequency plasma-enhanced chemical vapor deposition (RF-PECVD) system. The Si-H configuration of the a-Si:H/c-Si interface is regulated by optimizing the deposition temperature and post-annealing duration to improve the minority carrier lifetime (τeff) of a commercial Czochralski (Cz) silicon wafer. The mechanism of this improvement involves saturation of the microstructural defects with hydrogen evolved within the a-Si:H films due to the transformation from SiH2 into SiH during the annealing process. The post-annealing temperature is controlled to ∼180 °C so that silicon heterojunction solar cells (SHJ) could be prepared without an additional annealing step. To achieve better performance of the SHJ solar cells, we also optimize the thickness of the a-Si:H passivation layer. Finally, complete SHJ solar cells are fabricated using different temperatures for the a-Si:H film deposition to study the influence of the deposition temperature on the solar cell parameters. For the optimized a-Si:H deposition conditions, an efficiency of 18.41% is achieved on a textured Cz silicon wafer.

Cooperative tin oxide fullerene electron selective layers for high-performance planar perovskite solar cells

DOE PAGES

Ke, Weijun; Zhao, Dewei; Xiao, Chuanxiao; ...

2016-08-17

Both tin oxide (SnO 2) and fullerenes have been reported as electron selective layers (ESLs) for producing efficient lead halide perovskite solar cells. Here, we report that SnO 2 and fullerenes can work cooperatively to further boost the performance of perovskite solar cells. We find that fullerenes can be redissolved during perovskite deposition, allowing ultra-thin fullerenes to be retained at the interface and some dissolved fullerenes infiltrate into perovskite grain boundaries. The SnO 2 layer blocks holes effectively; whereas, the fullerenes promote electron transfer and passivate both the SnO 2/perovskite interface and perovskite grain boundaries. With careful device optimization, themore » best-performing planar perovskite solar cell using a fullerene passivated SnO 2 ESL has achieved a steady-state efficiency of 17.75% and a power conversion efficiency of 19.12% with an open circuit voltage of 1.12 V, a short-circuit current density of 22.61 mA cm -2, and a fill factor of 75.8% when measured under reverse voltage scanning. In conclusion, we find that the partial dissolving of fullerenes during perovskite deposition is the key for fabricating high-performance perovskite solar cells based on metal oxide/fullerene ESLs.« less

Alloy-Controlled Work Function for Enhanced Charge Extraction in All-Inorganic CsPbBr3 Perovskite Solar Cells.

PubMed

Ding, Jie; Zhao, Yuanyuan; Duan, Jialong; He, Benlin; Tang, Qunwei

2018-05-09

All-inorganic CsPbX 3 (X=I, Br) perovskite solar cells are regarded as cost-effective and stable alternatives for next-generation photovoltaics. However, sluggish charge extraction at CsPbX 3 /charge-transporting material interfaces, which arises from large interfacial energy differences, have markedly limited the further enhancement of solar cell performance. In this work, the work function (WF) of the back electrode is tuned by doping alloyed PtNi nanowires in carbon ink to promote hole extraction from CsPbBr 3 halides, while an intermediate energy by setting carbon quantum dots (CQDs) at TiO 2 /CsPbBr 3 interface bridges electron transportation. The preliminary results demonstrate that the matching WFs and intermediate energy level markedly reduce charge recombination. A power conversion efficiency of 7.17 % is achieved for the WF-tuned all-inorganic perovskite solar cell, in comparison with 6.10 % for the pristine device, and this is further increased to 7.86 % by simultaneously modifying with CQDs. The high efficiency and improved stability make WF-controlled all-inorganic perovskite solar cells promising to develop advanced photovoltaic platforms. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Room-temperature preparation of trisilver-copper-sulfide/polymer based heterojunction thin film for solar cell application

NASA Astrophysics Data System (ADS)

Lei, Yan; Yang, Xiaogang; Gu, Longyan; Jia, Huimin; Ge, Suxiang; Xiao, Pin; Fan, Xiaoli; Zheng, Zhi

2015-04-01

Solar cells devices based on inorganic/polymer heterojunction can be a possible solution to harvest solar energy and convert to electric energy with high efficiency through a cost-effective fabrication. The solution-process method can be easily used to produce large area devices. Moreover, due to the intrinsic different charge separation, diffusion or recombination in various semiconductors, the interfaces between each component may strongly influence the inorganic/polymer heterojunction performance. Here we prepared a n-type Ag3CuS2 (Eg = 1.25 eV) nanostructured film through a room-temperature element reaction process, which was confirmed as direct bandgap semiconductor through density function theory simulation. This Ag3CuS2 film was spin-coated with an organic semiconducting poly(3-hexythiophene) (P3HT) or polythieno[3,4-b]-thiophene-co-benzodithiophene (PTB7) film, which formed an inorganic/polymer heterojunction. After constructing it to a solar cell device, the power conversion efficiencies of 0.79% and 0.31% were achieved with simulated solar illumination on Ag3CuS2/P3HT and Ag3CuS2/PTB7, respectively. A possible mechanism was discussed and we showed the charge separation at interface of inorganic and polymer semiconductors played an important role.

The Redox Flow System for solar photovoltaic energy storage

NASA Technical Reports Server (NTRS)

Odonnell, P.; Gahn, R. F.; Pfeiffer, W.

1976-01-01

The interfacing of a Solar Photovoltaic System and a Redox Flow System for storage was workable. The Redox Flow System, which utilizes the oxidation-reduction capability of two redox couples, in this case iron and titanium, for its storage capacity, gave a relatively constant output regardless of solar activity so that a load could be run continually day and night utilizing the sun's energy. One portion of the system was connected to a bank of solar cells to electrochemically charge the solutions, while a separate part of the system was used to electrochemically discharge the stored energy.

NASA's Parker Solar Probe and Solar Orbiter Missions: Discovering the Secrets of our Star

NASA Astrophysics Data System (ADS)

Zurbuchen, T.

2017-12-01

This session will explore the importance of the Parker Solar Probe and Solar Orbiter missions to NASA Science, and the preparations for discoveries from these missions. NASA's Parker Solar Probe and Solar Orbiter Missions have complementary missions and will provide unique and unprecedented contributions to heliophysics and astrophysics overall. These inner heliospheric missions will also be part of the Heliophysics System Observatory which includes an increasing amount of innovative new technology and architectures to address science and data in an integrated fashion and advance models through assimilation and system-level tests. During this talk, we will briefly explore how NASA Heliophysics research efforts not only increase our understanding and predictive capability of space weather phenomena, but also provide key insights on fundamental processes important throughout the universe.

Discovering the 50 Years of Solar System Exploration: Sharing Your Science with the Public

NASA Astrophysics Data System (ADS)

Buxner, Sanlyn; Dalton, H.; Shipp, S.; Shupla, C.; Halligan, E.; Boonstra, D.; Wessen, A.; Baerg, G.; Davis, P.; Burdick, A.; Zimmerman Brachman, R.

2012-10-01

The Year of the Solar System (YSS) offers ways for scientists to bring NASA’s science discoveries to their audiences! YSS and the continuing salute to the 50-year history of solar system exploration provide an integrated picture of our new understanding of the solar system for educators and the general public. During the last five decades, NASA has launched a variety of robotic spacecraft to study our solar system. Over that time, our understanding of planets has been revolutionized, as has the technology that has made these discoveries possible.Looking forward, the numerous ongoing and future robotic missions are returning new discoveries of our solar system at an unprecedented rate. YSS combines the discoveries of past NASA planetary missions with the most recent findings of the ongoing missions and connects them to related topics based on the big questions of planetary science, including solar system formation, volcanism, ice, and possible life elsewhere. Planetary scientists are encouraged to get involved in YSS in a variety of ways: - Give a talk at a local museum, planetarium, library, or school to share YSS and your research - Partner with a local educational institution to organize a night sky viewing or mission milestone community event - Work with a classroom teacher to explore one of the topics with students - Connect with a planetary science E/PO professional to identify ways to participate, like creating podcasts,vodcasts, or contributing to monthly topics - Share your ideas for events and activities with the planetaryE/PO community to identify partners and pathways for distribution - And more! Promotional and educational materials, updates, a calendar of activities, and a space to share experiences are available at NASA’s Solar System website: http://solarsystem.nasa.gov/yss. This is an exciting time in planetary sciences as we learn about New Worlds and make New Discoveries!

Enhanced Lifetime of Polymer Solar Cells by Surface Passivation of Metal Oxide Buffer Layers.

PubMed

Venkatesan, Swaminathan; Ngo, Evan; Khatiwada, Devendra; Zhang, Cheng; Qiao, Qiquan

2015-07-29

The role of electron selective interfaces on the performance and lifetime of polymer solar cells were compared and analyzed. Bilayer interfaces consisting of metal oxide films with cationic polymer modification namely poly ethylenimine ethoxylated (PEIE) were found to enhance device lifetime compared to bare metal oxide films when used as an electron selective cathode interface. Devices utilizing surface-modified metal oxide layers showed enhanced lifetimes, retaining up to 85% of their original efficiency when stored in ambient atmosphere for 180 days without any encapsulation. The work function and surface potential of zinc oxide (ZnO) and ZnO/PEIE interlayers were evaluated using Kelvin probe and Kelvin probe force microscopy (KPFM) respectively. Kelvin probe measurements showed a smaller reduction in work function of ZnO/PEIE films compared to bare ZnO films when aged in atmospheric conditions. KPFM measurements showed that the surface potential of the ZnO surface drastically reduces when stored in ambient air for 7 days because of surface oxidation. Surface oxidation of the interface led to a substantial decrease in the performance in aged devices. The enhancement in the lifetime of devices with a bilayer interface was correlated to the suppressed surface oxidation of the metal oxide layers. The PEIE passivated surface retained a lower Fermi level when aged, which led to lower trap-assisted recombination at the polymer-cathode interface. Further photocharge extraction by linearly increasing voltage (Photo-CELIV) measurements were performed on fresh and aged samples to evaluate the field required to extract maximum charges. Fresh devices with a bare ZnO cathode interlayer required a lower field than devices with ZnO/PEIE cathode interface. However, aged devices with ZnO required a much higher field to extract charges while aged devices with ZnO/PEIE showed a minor increase compared to the fresh devices. Results indicate that surface modification can act as a suitable passivation layer to suppress oxidation in metal oxide thin films for enhanced lifetime in inverted organic solar cells.

Surface modifications of photoanodes in dye sensitized solar cells: enhanced light harvesting and reduced recombination

NASA Astrophysics Data System (ADS)

Saxena, Vibha; Aswal, D. K.

2015-06-01

In a quest to harvest solar power, dye-sensitized solar cells (DSSCs) have potential for low-cost eco-friendly photovoltaic devices. The major processes which govern the efficiency of a DSSC are photoelectron generation, injection of photo-generated electrons to the conduction band (CB) of the mesoporous nanocrystalline semiconductor (nc-SC); transport of CB electrons through nc-SC and subsequent collection of CB electrons at the counter electrode (CE) through the external circuit; and dye regeneration by redox couple or hole transport layer (HTL). Most of these processes occur at various interfaces of the photoanode. In addition, recombination losses of photo-generated electrons with either dye or redox molecules take place at the interfaces. Therefore, one of the key requirements for high efficiency is to improve light harvesting of the photoanode and to reduce the recombination losses at various interfaces. In this direction, surface modification of the photoanode is the simplest method among the various other approaches available in the literature. In this review, we present a comprehensive discussion on surface modification of the photoanode, which has been adopted in the literature for not only enhancing light harvesting but also reducing recombination. Various approaches towards surface modification of the photoanode discussed are (i) fluorine-doped tin oxide (FTO)/nc-SC interface modified via a compact layer of semiconductor material which blocks exposed sites of FTO to electrolyte (or HTL), (ii) nc-SC/dye interface modification either through acid treatment resulting in enhanced dye loading due to a positively charged surface or by depositing insulating/semiconducting blocking layer on the nc-SC surface, which acts as a tunneling barrier for recombination, (iii) nc-SC/dye interface modified by employing co-adsorbents which helps in reducing the dye aggregation and thereby recombination, and (iv) dye/electrolyte (or dye/HTL) interface modification using additives which provides surface passivation as well as positive movement of the nc-SC Fermi level owing to negative charge at the surface and hence improves light harvesting and reduced recombination. Finally, we discuss the advantages and disadvantages of various approaches towards high-efficiency DSSCs.

NASA Science Mission Directorate's Year of the Solar System: An Opportunity for Scientist Involvement

NASA Astrophysics Data System (ADS)

Dalton, Heather; Shipp, S.; Boonstra, D.; Shupla, C.; CoBabe-Ammann, E.; LaConte, K.; Ristvey, J.; Wessen, A.; Zimmerman-Bachman, R.; Science E/PO Community, Planetary

2010-10-01

Between October 2010 and August 2012 - across a Martian year - a large number of Science Mission Directorate's (SMD) planetary missions will pass milestones (e.g., EPOXI, Stardust-NExT, MESSENGER, Dawn, Juno, GRAIL, and Mars Science Laboratory), with many other missions continuing to explore (e.g., Lunar Reconnaissance Orbiter, Mars Odyssey, Mars Exploration Rovers, Mars Reconnaissance Orbiter, Mars Express, Cassini, New Horizons, and Voyager). This Year of the Solar System (YSS) offers the Planetary Science Education and Public Outreach (E/PO) community an opportunity to collaborate with each other and the science community. Based on audience needs from formal and informal educators, YSS is structured to have monthly thematic topics that are driven by mission milestones, as well as observing opportunities. YSS will connect to ongoing and planned events nationwide. A website for YSS is in development and will be hosted off of the existing JPL Solar System website (http://solarsystem.nasa.gov/index.cfm). Once live, scientists, educators, and E/PO professionals will have a place to interact and collaborate. YSS will tie to NASA's Big Questions in Planetary Science - how did the Sun's family of planets and minor bodies originate and how have they evolved? - how did life begin and evolve on Earth, is it elsewhere, and what characteristics of the solar system lead to the origins of life? The thematic topics are broad in order to encompass many missions and planetary bodies each month, as well as address the Big Questions. YSS will kick off in October with the theme "Solar System Components and Scale” and a national event involving building solar system scale models across the country. Scientists are encouraged to contact schools, museums, planetaria, etc. in their communities to give presentations, provide science content, and collaborate on educational materials and events related to YSS.

Committee on solar and space physics

NASA Astrophysics Data System (ADS)

Lanzerotti, L. J.

The Committee on Solar and Space Physics (CSSP) is the Committee of the Space Science Board (SSB) of the National Research Council that is responsible for providing scientific advice to NASA in areas of solar/solar-terrestrial/space-plasma physics. The committee, composed of members who serve 3-year terms, wishes to solicit comments from colleagues on topics of interest to them and related to issues in the field.Current subjects on which the committee is devoting considerable effort include the following: (a) considerations of data handling and data systems in solar-terrestrial research for the future (This is being carried out with the encouragement of the SSB and its Committee on Data Management. The activity is in collaboration with the Committee on Solar-Terrestrial Research (CSTR) of the Geophysics Research Board. The handling, integration, and dissemination of solar-terrestrial data obtained by all techniques will be addressed. Chairmen of the responsible subgroup are D. J. Williams (CSSP) and M. A. Shea (CSTR).); (b) consideration of the policies and issues associated with a revitalized Explorer satellite program responsive to the requirements of the solar-terrestrial physics community (Inputs of ideas for potential Explorer missions have been received from a wide range of the community and will be further elaborated upon by additional community participation. A number of these ideas and examples will form a portion of a report discussing solar-terrestrial science topics of high contemporary interest that could be well addressed with Explorerclass missions.); (c) inputs to a more comprehensive consideration of the requirements for theoretical research in all the space sciences (This is an overall task of the Space Science Board. The CSSP response relies heavily upon the Colgate committee report on space plasma physics.); (d) a future workshop, in collaboration with the Space Science Committee of the European Science foundation, on potential cooperative work in space plasma physics with European nations (Four major program items will be addressed, including reviews of several major scientific achievements within the field, a review of the status of solar and space plasma physics as academic subjects in the U.S. and in Western Europe, a review of future research programs, and a discussion of the forms of collaboration between the U.S. and European space plasma physics communities, with recommendations for the future. The workshop will be held in the U.S., tentatively during the 1982-83 academic year.); (e) continuing dialogue with NASA public relations officials and other knowledgeable individuals regarding the status of public knowledge of the results, importance, and applications of solar-terrestrial research.); (f) discussions with relevant officials concerning the issues of scientific funding in the United States, particularly as related to solar-terrestrial research.

Hydrophobic Light-to-Heat Conversion Membranes with Self-Healing Ability for Interfacial Solar Heating.

PubMed

Zhang, Lianbin; Tang, Bo; Wu, Jinbo; Li, Renyuan; Wang, Peng

2015-09-02

Self-healing hydrophobic light-to-heat conversion membranes for interfacial solar heating are fabricated by deposition of light-to-heat conversion material of polypyrrole onto a porous stainless-steel mesh, followed by hydrophobic fluoroalkylsilane modification. The mesh-based membranes spontaneously stay at the water-air interface, collect and convert solar light into heat, and locally heat only the water surface for enhanced evaporation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A First Comparison of Millimeter Continuum and Mg ii Ultraviolet Line Emission from the Solar Chromosphere

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bastian, T. S.; Chintzoglou, G.; De Pontieu, B.

We present joint observations of the Sun by the Atacama Large Millimeter/submillimeter Array (ALMA) and the Interface Region Imaging Spectrograph ( IRIS ). Both millimeter/submillimeter- λ continuum emission and ultraviolet (UV) line emission originate from the solar chromosphere and both have the potential to serve as powerful and complementary diagnostics of physical conditions in this enigmatic region of the solar atmosphere. The observations were made of a solar active region on 2015 December 18 as part of the ALMA science verification effort. A map of the Sun’s continuum emission was obtained by ALMA at a wavelength of 1.25 mm (239more » GHz). A contemporaneous map was obtained by IRIS in the Mg ii h doublet line at 2803.5 Å. While a clear correlation between the 1.25 mm brightness temperature T{sub B} and the Mg ii h line radiation temperature T {sub rad} is observed, the slope is <1, perhaps as a result of the fact that these diagnostics are sensitive to different parts of the chromosphere and that the Mg ii h line source function includes a scattering component. There is a significant difference (35%) between the mean T{sub B} (1.25 mm) and mean T {sub rad} (Mg ii). Partitioning the maps into “sunspot,” “quiet areas,” and “plage regions” we find the relation between the IRIS Mg ii h line T {sub rad} and the ALMA T {sub B} region-dependent. We suggest this may be the result of regional dependences of the formation heights of the IRIS and ALMA diagnostics and/or the increased degree of coupling between the UV source function and the local gas temperature in the hotter, denser gas in plage regions.« less

A study of integrated learning and the value of science in remote education: using the Internet to relay the total solar eclipse of 2001 June 11 in Africa

NASA Astrophysics Data System (ADS)

Takahashi, N.; Agata, H.; Maeda, K.; Okyudo, M..; Yamazaki, Y.

A total solar eclipse was observed on 2001 June 21 in Angola, Zambia, and Zimbabwe in Africa. For the purpose of promotion of science education using a solar eclipse as an educational project, the whole image and an enlarged image of the Sun, that showed the process of an eclipse and how things went in the observation area, were broadcast to the world through the Internet (Live Eclipse). Such images were distributed to four primary schools in Hiroshima and the Science and Technology Museum in Tokyo to give a remote lecture through computers. To find the effectiveness of the lecture, the learning effect on the participating children was examined two times before and after the remote lecture on the solar eclipse.

U.S. Solar-Terrestrial Research Program

NASA Astrophysics Data System (ADS)

Intriligator, Devrie S.

The Committee on Solar-Terrestrial Research (CSTR) of the National Research Council of the National Academy of Sciences is charged with looking after the health of solar-terrestrial research in the United States. In 1984 the National Academy Press published the CSTR report “National Solar-Terrestrial Research Program.” This program implements the recommendations of the earlier National Research Council study “Solar-Terrestrial Research for the 1980's” (1981). The earlier study, which took over 18 months to complete and involved the participation of more than 150 scientists, specifically identified the principal scientific and management recommendations required for a balanced solar-terrestrial program. The present study was undertaken by CSTR in the fall of 1983 in response to a request from several concerned federal agencies and the Board on Atmospheric Sciences and Climate. Together, the two studies constitute a set that prescribes a broad-gaged solar-terrestrial program.

Solar Polar ORbit Telescope (SPORT): A Potential Heliophysics Mission of China

NASA Astrophysics Data System (ADS)

Liu, Ying

We describe a spacecraft mission, named Solar Polar ORbit Telescope (SPORT), which is currently under a scientific and engineering background study in China. SPORT was originally proposed in 2004 by the National Space Science Center, Chinese Academy of Sciences. It will carry a suite of remote-sensing and in-situ instruments to observe coronal mass ejections (CMEs), solar high-latitude magnetism, and the fast solar wind from a polar orbit around the Sun. It is intended to be the first mission that carries remote-sensing instruments from a high-latitude orbit around the Sun and the first mission that could measure solar high-latitude magnetism. The first extended view of the polar region of the Sun and the ecliptic plane enabled by SPORT will provide a unique opportunity to study CME propagation through the inner heliosphere and solar high-latitude magnetism giving rise to eruptions and the fast solar wind.

Simulation of an electrowetting solar concentration cell

NASA Astrophysics Data System (ADS)

Khan, Iftekhar; Rosengarten, Gary

2015-09-01

Electrowetting control of liquid lenses has emerged as a novel approach for solar tracking and concentration. Recent studies have demonstrated the concept of steering sunlight using thin electrowetting cells without the use of any bulky mechanical equipment. Effective application of this technique may facilitate designing thin and flat solar concentrators. Understanding the behavior of liquid-liquid and liquid-solid interface of the electrowetting cell through trial and error experimental processes is not efficient and is time consuming. In this paper, we present a simulation model to predict the liquid-liquid and liquid-solid interface behavior of electrowetting cell as a function of various parameters such as applied voltage, dielectric constant, cell size etc. We used Comsol Multiphysics simulations incorporating experimental data of different liquids. We have designed both two dimensional and three dimensional simulation models, which predict the shape of the liquid lenses. The model calculates the contact angle using the Young-Lippman equation and uses a moving mesh interface to solve the Navier-stokes equation with Navier slip wall boundary condition. Simulation of the electric field from the electrodes is coupled to the Young-Lippman equation. The model can also be used to determine operational characteristics of other MEMS electrowetting devices such as electrowetting display, optical switches, electronic paper, electrowetting Fresnel lens etc.

Controllable Spatial Configuration on Cathode Interface for Enhanced Photovoltaic Performance and Device Stability.

PubMed

Li, Jiangsheng; Duan, Chenghao; Wang, Ning; Zhao, Chengjie; Han, Wei; Jiang, Li; Wang, Jizheng; Zhao, Yingjie; Huang, Changshui; Jiu, Tonggang

2018-05-08

The molecular structure of cathode interface modification materials can affect the surface morphology of the active layer and key electron transfer processes occurring at the interface of polymer solar cells in inverted structures mostly due to the change of molecular configuration. To investigate the effects of spatial configuration of the cathode interfacial modification layer on polymer solar cells device performances, we introduced two novel organic ionic salts (linear NS2 and three-dimensional (3D) NS4) combined with the ZnO film to fabricate highly efficient inverted solar cells. Both organic ionic salts successfully decreased the surface traps of the ZnO film and made its work function more compatible. Especially NS4 in three-dimensional configuration increased the electron mobility and extraction efficiency of the interfacial film, leading to a significant improvement of device performance. Power conversion efficiency (PCE) of 10.09% based on NS4 was achieved. Moreover, 3D interfacial modification could retain about 92% of its initial PCE over 160 days. It is proposed that 3D interfacial modification retards the element penetration-induced degradation without impeding the electron transfer from the active layer to the ZnO film, which significantly improves device stability. This indicates that inserting three-dimensional organic ionic salt is an efficient strategy to enhance device performance.

Evolution of a Native Oxide Layer at the a-Si:H/c-Si Interface and Its Influence on a Silicon Heterojunction Solar Cell.

PubMed

Liu, Wenzhu; Meng, Fanying; Zhang, Xiaoyu; Liu, Zhengxin

2015-12-09

The interface microstructure of a silicon heterojunction (SHJ) solar cell was investigated. We found an ultrathin native oxide layer (NOL) with a thickness of several angstroms was formed on the crystalline silicon (c-Si) surface in a very short time (∼30 s) after being etched by HF solution. Although the NOL had a loose structure with defects that are detrimental for surface passivation, it acted as a barrier to restrain the epitaxial growth of hydrogenated amorphous silicon (a-Si:H) during the plasma-enhanced chemical vapor deposition (PECVD). The microstructure change of the NOL during the PECVD deposition of a-Si:H layers with different conditions and under different H2 plasma treatments were systemically investigated in detail. When a brief H2 plasma was applied to treat the a-Si:H layer after the PECVD deposition, interstitial oxygen and small-size SiO2 precipitates were transformed to hydrogenated amorphous silicon suboxide alloy (a-SiO(x):H, x ∼ 1.5). In the meantime, the interface defect density was reduced by about 50%, and the parameters of the SHJ solar cell were improved due to the post H2 plasma treatment.

Insights into collaborative separation process of photogenerated charges and superior performance of solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Xiangyang, E-mail: lxy081276@126.com; Wang, Shun; Zheng, Haiwu

2016-07-25

ZnO nanowires/Cu{sub 4}Bi{sub 4}S{sub 9} (ZnO/CBS) and ZnO nanowires/CBS-graphene nanoplates (ZnO/CBS-GNs), as well as two types of solar cells were prepared. The photovoltaic responses of CBS-GNs and ZnO/CBS-GNs can be improved with incorporation of GNs. The transient surface photovoltage (TPV) can provide detailed information on the separation and transport of photogenerated carriers. The multichannel separation process from the TPVs indicates that the macro-photoelectric signals can be attributed to the photogenerated charges separated at the interface of CBS/GNs, rather than CBS/ZnO. The multi-interfacial recombination is the major carrier loss, and the hole selective p-V{sub 2}O{sub 5} can efficiently accelerate the chargemore » extraction to the external circuit. The ZnO/CBS-GNs cell exhibits the superior performance, and the highest efficiency is 10.9%. With the adequate interfaces of CBS/GNs, GNs conductive network, energy level matching, etc., the excitons can easily diffuse to the interface of CBS/GNs, and the separated electrons and holes can be collected quickly, inducing the high photoelectric properties. Here, a facile strategy for solid state solar cells with superior performance presents a potential application.« less

A Biopolymer Heparin Sodium Interlayer Anchoring TiO2 and MAPbI3 Enhances Trap Passivation and Device Stability in Perovskite Solar Cells.

PubMed

You, Shuai; Wang, Hui; Bi, Shiqing; Zhou, Jiyu; Qin, Liang; Qiu, Xiaohui; Zhao, Zhiqiang; Xu, Yun; Zhang, Yuan; Shi, Xinghua; Zhou, Huiqiong; Tang, Zhiyong

2018-04-18

Traps in the photoactive layer or interface can critically influence photovoltaic device characteristics and stabilities. Here, traps passivation and retardation on device degradation for methylammonium lead trihalide (MAPbI 3 ) perovskite solar cells enabled by a biopolymer heparin sodium (HS) interfacial layer is investigated. The incorporated HS boosts the power conversion efficiency from 17.2 to 20.1% with suppressed hysteresis and Shockley-Read-Hall recombination, which originates primarily from the passivation of traps near the interface between the perovskites and the TiO 2 cathode. The incorporation of an HS interfacial layer also leads to a considerable retardation of device degradation, by which 85% of the initial performance is maintained after 70 d storage in ambient environment. Aided by density functional theory calculations, it is found that the passivation of MAPbI 3 and TiO 2 surfaces by HS occurs through the interactions of the functional groups (COO - , SO 3 - , or Na + ) in HS with undersaturated Pb and I ions in MAPbI 3 and Ti 4+ in TiO 2 . This work demonstrates a highly viable and facile interface strategy using biomaterials to afford high-performance and stable perovskite solar cells. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

NEOview: Near Earth Object Data Discovery and Query

NASA Astrophysics Data System (ADS)

Tibbetts, M.; Elvis, M.; Galache, J. L.; Harbo, P.; McDowell, J. C.; Rudenko, M.; Van Stone, D.; Zografou, P.

2013-10-01

Missions to Near Earth Objects (NEOs) figure prominently in NASA's Flexible Path approach to human space exploration. NEOs offer insight into both the origins of the Solar System and of life, as well as a source of materials for future missions. With NEOview scientists can locate NEO datasets, explore metadata provided by the archives, and query or combine disparate NEO datasets in the search for NEO candidates for exploration. NEOview is a software system that illustrates how standards-based interfaces facilitate NEO data discovery and research. NEOview software follows a client-server architecture. The server is a configurable implementation of the International Virtual Observatory Alliance (IVOA) Table Access Protocol (TAP), a general interface for tabular data access, that can be deployed as a front end to existing NEO datasets. The TAP client, seleste, is a graphical interface that provides intuitive means of discovering NEO providers, exploring dataset metadata to identify fields of interest, and constructing queries to retrieve or combine data. It features a powerful, graphical query builder capable of easing the user's introduction to table searches. Through science use cases, NEOview demonstrates how potential targets for NEO rendezvous could be identified by combining data from complementary sources. Through deployment and operations, it has been shown that the software components are data independent and configurable to many different data servers. As such, NEOview's TAP server and seleste TAP client can be used to create a seamless environment for data discovery and exploration for tabular data in any astronomical archive.

Eight river principles for navigating the science–policy interface

EPA Science Inventory

Scientists and policymakers often work together to develop policy about the sustainable use of river ecosystems. River science plays an important role in developing river policy but how can key aspects of river science be conveyed as a heuristic to navigate the interface between ...

Scientific Investigation of the Jovian System: the Jupiter System Observer Mission Concept

NASA Astrophysics Data System (ADS)

Spilker, Thomas R.; Senske, D. A.; Prockter, L.; Kwok, J. H.; Tan-Wang, G. H.; SDT, JSO

2007-10-01

NASA's Science Mission Directorate (SMD), in efforts to start an outer solar system flagship mission in the near future, commissioned studies of mission concepts for four high-priority outer solar system destinations: Europa, the Jovian system, Titan, and Enceladus. Our team has identified and evaluated science and mission architectures to investigate major elements of the Jovian system: Jupiter, the Galilean moons, rings, and magnetosphere, and their interactions. SMD dubbed the mission concept the "Jupiter System Observer (JSO)." At abstract submission this JPL-led study is nearly complete, with final report submission in August 2007. SMD intends to select a subset of these four concepts for additional detailed study, leading to a potential flagship mission new start. A rich set of science objectives that JSO can address quite well have been identified. The highly capable science payload (including 50-cm optic), an extensive tour with multiple close flybys of Io, Europa, Ganymede and Callisto, and a significant time in orbit at Ganymede, addresses a large set of Solar System Exploration Decadal Survey (2003) and NASA Solar System Exploration Roadmap (2006) high-priority objectives. With the engineering team, the Science Definition Team evaluated a suite of mission architectures and the science they enable to arrive at two architectures that provide the best science for their estimated mission costs. This paper discusses the science objectives and operational capabilities and considerations for these mission concepts. This work was performed at JPL, APL, and other institutions under contract to NASA.

Straw man trade between multi-junction, gallium arsenide, and silicon solar cells

NASA Technical Reports Server (NTRS)

Gaddy, Edward M.

1995-01-01

Multi-junction (MJ), gallium arsenide (GaAs), and silicon (Si) solar cells have respective test efficiencies of approximately 24%, 18.5% and 14.8%. Multi-junction and gallium arsenide solar cells weigh more than silicon solar cells and cost approximately five times as much per unit power at the cell level. A straw man trade is performed for the TRMM spacecraft to determine which of these cell types would have offered an overall performance and price advantage to the spacecraft. A straw man trade is also performed for the multi-junction cells under the assumption that they will cost over ten times that of silicon cells at the cell level. The trade shows that the TRMM project, less the cost of the instrument, ground systems and mission operations, would spend approximately $552 thousand dollars per kilogram to launch and service science in the case of the spacecraft equipped with silicon solar cells. If these cells are changed out for gallium arsenide solar cells, an additional 31 kilograms of science can be launched and serviced at a price of approximately $90 thousand per kilogram. The weight reduction is shown to derive from the smaller area of the array and hence reductions in the weight of the array substrate and supporting structure. If the silicon solar cells are changed out for multi-junction solar cells, an additional 45 kilograms of science above the silicon base line can be launched and serviced at a price of approximately $58 thousand per kilogram. The trade shows that even if the multi-junction arrays are priced over ten times that of silicon cells, a price that is much higher than projected, that the additional 45 kilograms of science are launched and serviced at $182 thousand per kilogram. This is still much less than original $552 thousand per kilogram to launch and service the science. Data and qualitative factors are presented to show that these figures are subject to a great deal of uncertainty. Nonetheless, the benefit of the higher efficiency solar cells for TRMM is far greater than the uncertainties in the analysis.