Science.gov

Sample records for photovoltaic solar cells

  1. Solar Photovoltaic Cells.

    ERIC Educational Resources Information Center

    Mickey, Charles D.

    1981-01-01

    Reviews information on solar radiation as an energy source. Discusses these topics: the key photovoltaic material; the bank theory of solids; conductors, semiconductors, and insulators; impurity semiconductors; solid-state photovoltaic cell operation; limitations on solar cell efficiency; silicon solar cells; cadmium sulfide/copper (I) sulfide…

  2. Photovoltaic solar cell

    DOEpatents

    Nielson, Gregory N; Okandan, Murat; Cruz-Campa, Jose Luis; Resnick, Paul J

    2013-11-26

    A photovoltaic solar cell for generating electricity from sunlight is disclosed. The photovoltaic solar cell comprises a plurality of spaced-apart point contact junctions formed in a semiconductor body to receive the sunlight and generate the electicity therefrom, the plurality of spaced-apart point contact junctions having a first plurality of regions having a first doping type and a second plurality of regions having a second doping type. In addition, the photovoltaic solar cell comprises a first electrical contact electrically connected to each of the first plurality of regions and a second electrical contact electrically connected to each of the second plurality of regions, as well as a passivation layer covering major surfaces and sidewalls of the photovoltaic solar cell.

  3. Photovoltaic solar cell

    DOEpatents

    Nielson, Gregory N; Cruz-Campa, Jose Luis; Okandan, Murat; Resnick, Paul J

    2014-05-20

    A photovoltaic solar cell for generating electricity from sunlight is disclosed. The photovoltaic solar cell comprises a plurality of spaced-apart point contact junctions formed in a semiconductor body to receive the sunlight and generate the electricity therefrom, the plurality of spaced-apart point contact junctions having a first plurality of regions having a first doping type and a second plurality of regions having a second doping type. In addition, the photovoltaic solar cell comprises a first electrical contact electrically connected to each of the first plurality of regions and a second electrical contact electrically connected to each of the second plurality of regions, as well as a passivation layer covering major surfaces and sidewalls of the photovoltaic solar cell.

  4. Photovoltaic solar cell

    DOEpatents

    Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

    2015-09-08

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  5. Photovoltaic solar concentrator

    SciTech Connect

    Nielson, Gregory N.; Cruz-Campa, Jose Luis; Okandan, Murat; Resnick, Paul J.; Sanchez, Carlos Anthony; Clews, Peggy J.; Gupta, Vipin P.

    2015-09-08

    A process including forming a photovoltaic solar cell on a substrate, the photovoltaic solar cell comprising an anchor positioned between the photovoltaic solar cell and the substrate to suspend the photovoltaic solar cell from the substrate. A surface of the photovoltaic solar cell opposite the substrate is attached to a receiving substrate. The receiving substrate may be bonded to the photovoltaic solar cell using an adhesive force or a metal connecting member. The photovoltaic solar cell is then detached from the substrate by lifting the receiving substrate having the photovoltaic solar cell attached thereto and severing the anchor connecting the photovoltaic solar cell to the substrate. Depending upon the type of receiving substrate used, the photovoltaic solar cell may be removed from the receiving substrate or remain on the receiving substrate for use in the final product.

  6. Tandem photovoltaic solar cells and increased solar energy conversion efficiency

    NASA Technical Reports Server (NTRS)

    Loferski, J. J.

    1976-01-01

    Tandem photovoltaic cells, as proposed by Jackson (1955) to increase the efficiency of solar energy conversion, involve the construction of a system of stacked p/n homojunction photovoltaic cells composed of different semiconductors. It had been pointed out by critics, however, that the total power which could be extracted from the cells in the stack placed side by side was substantially greater than the power obtained from the stacked cells. A reexamination of the tandem cell concept in view of the development of the past few years is conducted. It is concluded that the use of tandem cell systems in flat plate collectors, as originally envisioned by Jackson, may yet become feasible as a result of the development of economically acceptable solar cells for large scale terrestrial power generation.

  7. Potential high efficiency solar cells: Applications from space photovoltaic research

    NASA Technical Reports Server (NTRS)

    Flood, D. J.

    1986-01-01

    NASA involvement in photovoltaic energy conversion research development and applications spans over two decades of continuous progress. Solar cell research and development programs conducted by the Lewis Research Center's Photovoltaic Branch have produced a sound technology base not only for the space program, but for terrestrial applications as well. The fundamental goals which have guided the NASA photovoltaic program are to improve the efficiency and lifetime, and to reduce the mass and cost of photovoltaic energy conversion devices and arrays for use in space. The major efforts in the current Lewis program are on high efficiency, single crystal GaAs planar and concentrator cells, radiation hard InP cells, and superlattice solar cells. A brief historical perspective of accomplishments in high efficiency space solar cells will be given, and current work in all of the above categories will be described. The applicability of space cell research and technology to terrestrial photovoltaics will be discussed.

  8. Photovoltaic technology: the case for thin-film solar cells

    PubMed

    Shah; Torres; Tscharner; Wyrsch; Keppner

    1999-07-30

    The advantages and limitations of photovoltaic solar modules for energy generation are reviewed with their operation principles and physical efficiency limits. Although the main materials currently used or investigated and the associated fabrication technologies are individually described, emphasis is on silicon-based solar cells. Wafer-based crystalline silicon solar modules dominate in terms of production, but amorphous silicon solar cells have the potential to undercut costs owing, for example, to the roll-to-roll production possibilities for modules. Recent developments suggest that thin-film crystalline silicon (especially microcrystalline silicon) is becoming a prime candidate for future photovoltaics. PMID:10426984

  9. Photovoltaic Test and Demonstration Project. [for solar cell power systems

    NASA Technical Reports Server (NTRS)

    Forestieri, A. F.; Brandhorst, H. W., Jr.; Deyo, J. N.

    1976-01-01

    The Photovoltaic Test and Demonstration Project was initiated by NASA in June, 1975, to develop economically feasible photovoltaic power systems suitable for a variety of terrestrial applications. Objectives include the determination of operating characteristic and lifetimes of a variety of solar cell systems and components and development of methodology and techniques for accurate measurements of solar cell and array performance and diagnostic measurements for solar power systems. Initial work will be concerned with residential applications, with testing of the first prototype system scheduled for June, 1976. An outdoor 10 kW array for testing solar power systems is under construction.

  10. Laminated photovoltaic modules using back-contact solar cells

    DOEpatents

    Gee, James M.; Garrett, Stephen E.; Morgan, William P.; Worobey, Walter

    1999-09-14

    Photovoltaic modules which comprise back-contact solar cells, such as back-contact crystalline silicon solar cells, positioned atop electrically conductive circuit elements affixed to a planar support so that a circuit capable of generating electric power is created. The modules are encapsulated using encapsulant materials such as EVA which are commonly used in photovoltaic module manufacture. The module designs allow multiple cells to be electrically connected in a single encapsulation step rather than by sequential soldering which characterizes the currently used commercial practices.

  11. Production of solar photovoltaic cells on the Moon

    NASA Technical Reports Server (NTRS)

    Criswell, David R.; Ignatiev, Alex

    1991-01-01

    Solar energy is directly available on the sunward lunar surface. Most, if not all, the materials are available on the Moon to make silicon based solar photovoltaic cells. A few additional types are possible. There is a small but growing literature on production of lunar derived solar cells. This literature is reviewed. Topics explored include trade-offs of local production versus import of key materials, processing options, the scale and nature of production equipment, implications of storage requirements, and the end-uses of the energy. Directions for future research and demonstrations are indicated.

  12. Quantifying Solar Cell Cracks in Photovoltaic Modules by Electroluminescence Imaging

    SciTech Connect

    Spataru, Sergiu; Hacke, Peter; Sera, Dezso; Glick, Stephen; Kerekes, Tamas; Teodorescu, Remus

    2015-06-14

    This article proposes a method for quantifying the percentage of partially and totally disconnected solar cell cracks by analyzing electroluminescence images of the photovoltaic module taken under high- and low-current forward bias. The method is based on the analysis of the module's electroluminescence intensity distribution, applied at module and cell level. These concepts are demonstrated on a crystalline silicon photovoltaic module that was subjected to several rounds of mechanical loading and humidity-freeze cycling, causing increasing levels of solar cell cracks. The proposed method can be used as a diagnostic tool to rate cell damage or quality of modules after transportation. Moreover, the method can be automated and used in quality control for module manufacturers, installers, or as a diagnostic tool by plant operators and diagnostic service providers.

  13. Electrical research on solar cells and photovoltaic materials

    NASA Technical Reports Server (NTRS)

    Orehotsky, J.

    1984-01-01

    The flat-plate solar cell array program which increases the service lifetime of the photovoltaic modules used for terrestrial energy applications is discussed. The current-voltage response characteristics of the solar cells encapsulated in the modules degrade with service time and this degradation places a limitation on the useful lifetime of the modules. The most desirable flat-plate array system involves solar cells consisting of highly polarizable materials with similar electrochemical potentials where the cells are encapsulated in polymers in which ionic concentrations and mobilities are negligibly small. Another possible mechanism limiting the service lifetime of the photovoltaic modules is the gradual loss of the electrical insulation characteristics of the polymer pottant due to water absorption or due to polymer degradation from light or heat effects. The mechanical properties of various polymer pottant materials and of electrochemical corrosion mechanisms in solar cell material are as follows: (1) electrical and ionic resistivity; (2) water absorption kinetics and water solubility limits; and (3) corrosion characterization of various metallization systems used in solar cell construction.

  14. Solar Photovoltaic Cell/Module Shipments Report

    EIA Publications

    2016-01-01

    Summary data for the photovoltaic industry in the United States. Data includes manufacturing, imports, and exports of modules in the United States and its territories. Summary data include volumes in peak kilowatts and average prices. Where possible, imports and exports are listed by country, and shipments to the United States are listed by state.

  15. Periodically multilayered planar optical concentrator for photovoltaic solar cells

    SciTech Connect

    Solano, Manuel E.; Monk, Peter B.; Faryad, Muhammad; Lakhtakia, Akhlesh; Mallouk, Thomas E.

    2013-11-04

    A planar optical concentrator comprising a periodic multilayered isotropic dielectric material backed by a metallic surface-relief grating was theoretically examined for silicon photovoltaics. The concentrator was optimized using a differential evolution algorithm for solar-spectrum-integrated power-flux density. Further optimization was carried out for tolerance to variations in the incidence angle, spatial dimensions, and dielectric properties. The average electron-hole pair density in a silicon solar cell can be doubled, and the material costs substantially diminished by this concentrator, whose efficacy is due to the excitation of waveguide modes and multiple surface-plasmon-polariton waves in a broad spectral regime.

  16. Periodically multilayered planar optical concentrator for photovoltaic solar cells

    NASA Astrophysics Data System (ADS)

    Solano, Manuel E.; Faryad, Muhammad; Monk, Peter B.; Mallouk, Thomas E.; Lakhtakia, Akhlesh

    2013-11-01

    A planar optical concentrator comprising a periodic multilayered isotropic dielectric material backed by a metallic surface-relief grating was theoretically examined for silicon photovoltaics. The concentrator was optimized using a differential evolution algorithm for solar-spectrum-integrated power-flux density. Further optimization was carried out for tolerance to variations in the incidence angle, spatial dimensions, and dielectric properties. The average electron-hole pair density in a silicon solar cell can be doubled, and the material costs substantially diminished by this concentrator, whose efficacy is due to the excitation of waveguide modes and multiple surface-plasmon-polariton waves in a broad spectral regime.

  17. Semi-transparent polymer solar cells with excellent sub-bandgap transmission for third generation photovoltaics.

    PubMed

    Beiley, Zach M; Christoforo, M Greyson; Gratia, Paul; Bowring, Andrea R; Eberspacher, Petra; Margulis, George Y; Cabanetos, Clément; Beaujuge, Pierre M; Salleo, Alberto; McGehee, Michael D

    2013-12-23

    Semi-transparent organic photovoltaics are of interest for a variety of photovoltaic applications, including solar windows and hybrid tandem photovoltaics. The figure shows a photograph of our semi-transparent solar cell, which has a power conversion efficiency of 5.0%, with an above bandgap transmission of 34% and a sub-bandgap transmission of 81%. PMID:24123497

  18. Low cost and efficient photovoltaic conversion by nanocrystalline solar cells

    SciTech Connect

    Graetzel, M.

    1996-09-01

    Solar cells are expected to provide environmentally friendly solutions to the world`s energy supply problem. Learning from the concepts used by green plants we have developed a molecular photovoltaic device whose overall efficiency for AM 1.5 solar light to electricity has already attained 8-11%. The system is based on the sensitization of nanocrystalline oxide films by transition metal charge transfer sensitizers. In analogy to photosynthesis, the new chemical solar cell achieves the separation of the light absorption and charge carrier transport processes. Extraordinary yields for the conversion of incident photons into electric current are obtained, exceeding 90% for transition metal complexes within the wavelength range of their absorption band. The use of molten salt electrolytes together with coordination complexes of ruthenium as sensitizers and adequate sealing technology has endowed these cells with a remarkable stability making practical applications feasible. Seven industrial cooperations are presently involved in the development to bring these cells to the market. The first cells will be applied to supply electric power for consumer electronic devices. The launching of production of several products of this type is imminent and they should be on the market within the next two years. Quite aside from their intrinsic merits as photovoltaic device, the mesoscopic oxide semiconductor films developed in our laboratory offer attractive possibilities for a number of other applications. Thus, the first example of a nanocrystalline rocking chair battery will be demonstrated and its principle briefly discussed.

  19. Lightweight Solar Photovoltaic Blankets

    NASA Technical Reports Server (NTRS)

    Ceragioli, R.; Himmler, R.; Nath, P.; Vogeli, C.; Guha, S.

    1995-01-01

    Lightweight, flexible sheets containing arrays of stacked solar photovoltaic cells developed to supply electric power aboard spacecraft. Solar batteries satisfying stringent requirements for operation in outer space also adaptable to terrestrial environment. Attractive for use as long-lived, portable photovoltaic power sources. Cells based on amorphous silicon which offers potential for order-of-magnitude increases in power per unit weight, power per unit volume, and endurance in presence of ionizing radiation.

  20. Solar cells design for low and medium concentrating photovoltaic systems

    NASA Astrophysics Data System (ADS)

    Baig, Hasan; Heasman, Keith C.; Sarmah, Nabin; Mallick, Tapas

    2012-10-01

    The solar cell is the key element of any CPV system, and its design plays an important role in enhancing the performance of the entire system. Special types of cells are required in the CPV systems capable of operating at high concentrations and elevated temperatures. These Concentrator solar cells differ significantly from the usual solar cells in the method of manufacture, the overall cell design and their performance. Systematic design and manufacture of the cell ensures better performance in a given CPV system. A number of factors come into play while designing the solar cell for a specific system these include concentration, cell material properties, expected operating temperature, shape, bus bar configuration and finger spacing. Most of these variables are decided on based on some rules of thumb and PC1D calculations. However, there is scope for design improvement and cell optimization by performing a detailed analysis based on the illumination profile incident on the cell. Recent studies demonstrated the use of Finite element method to analyze the electrical behavior of PV cell under the influence of arbitrarily chosen illumination flux profiles. This study outlines a methodology and analysis procedure while performing a case study of a CPV system under development having a non-uniform illumination profile towards the exit of the concentrator. The LCPV system chosen is the Photovoltaic Facades of Reduced Costs Incorporating Devices with Optically Concentrating Elements (PRIDE) concentrator made of dielectric material. A coupled optical, thermal and electrical analysis is performed on the system to demonstrate the method useful in designing solar cells for low and medium concentrations.

  1. Geometric photovoltaics applied to amorphous silicon thin film solar cells

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, Timothy

    Geometrically generalized analytical expressions for device transport are derived from first principles for a photovoltaic junction. Subsequently, conventional planar and unconventional coaxial and hemispherical photovoltaic architectures are applied to detail the device physics of the junction based on their respective geometry. For the conventional planar cell, the one-dimensional transport equations governing carrier dynamics are recovered. For the unconventional coaxial and hemispherical junction designs, new multi-dimensional transport equations are revealed. Physical effects such as carrier generation and recombination are compared for each cell architecture, providing insight as to how non-planar junctions may potentially enable greater energy conversion efficiencies. Numerical simulations are performed for arrays of vertically aligned, nanostructured coaxial and hemispherical amorphous silicon solar cells and results are compared to those from simulations performed for the standard planar junction. Results indicate that fundamental physical changes in the spatial dependence of the energy band profile across the intrinsic region of an amorphous silicon p-i-n junction manifest as an increase in recombination current for non-planar photovoltaic architectures. Despite an increase in recombination current, however, the coaxial architecture still appears to be able to surpass the efficiency predicted for the planar geometry, due to the geometry of the junction leading to a decoupling of optics and electronics.

  2. Electrical research on solar cells and photovoltaic materials

    NASA Technical Reports Server (NTRS)

    Orehotsky, J.

    1985-01-01

    A systematic study of the properties of various polymer pottant materials and of the electrochemical corrosion mechanisms in solar cell materials is required for advancing the technology of terrestrial photovoltaic modules. The items of specific concern in this sponsored research activity involve: (1) kinetics of plasticizer loss in PVB, (2) kinetics of water absorption and desorption in PVB, (3) kinetics of water absorption and desorption in EVA, (4) the electrical properties at PVB as a function of temperature and humidity, (5) the electrical properties of EVA as a function of temperature and humidity, (6) solar cell corrosion characteristics, (7) water absorption effects in PVB and EVA, and (8) ion implantation and radiation effects in PVB and EVA.

  3. Photovoltaic solar concentrator module

    SciTech Connect

    Chiang, C.J.

    1991-05-16

    This invention consists of a planar photovoltaic concentrator module for producing an electrical signal from incident solar radiation which includes an electrically insulating housing having a front wall, an opposing back wall and a hollow interior. A solar cell having electrical terminals is positioned within the interior of the housing. A planar conductor is connected with a terminal of the solar cell of the same polarity. A lens forming the front wall of the housing is operable to direct solar radiation incident to the lens into the interior of the housing. A refractive optical element in contact with the solar cell and facing the lens receives the solar radiation directed into the interior of the housing by the lens and directs the solar radiation to the solar cell to cause the solar cell to generate an electrical signal. An electrically conductive planar member is positioned in the housing to rest on the housing back wall in supporting relation with the solar cell terminal of opposite polarity. The planar member is operable to dissipate heat radiated by the solar cell as the solar cell generates an electrical signal and further forms a solar cell conductor connected with the solar cell terminal to permit the electrical signal generated by the solar cell to be measured between the planar member and the conductor.

  4. Nanostructured photovoltaic devices for next generation solar cell

    NASA Astrophysics Data System (ADS)

    Kim, Sung Jin

    2008-10-01

    As the search for alternative sources of energy other than petroleum continues to expand, solar energy conversion has already been identified as one of the most promising technologies. In the past few years there has been extensive research focused on the next generation solar cells that can exceed the Shockley-Queisser limit (a model that predicts the maximum achievable efficiency for a given material with a given bandgap). Moreover, nanoengineering approaches to enhance solar power conversion efficiency have started to receive considerable interest. Even in the most efficient commercially available solar devices utilizing crystalline silicon, a major portion of the absorbed ultraviolet photon energy is wasted as heat. Furthermore, this heat is detrimental to device reliability. Colloidal nanocrystal quantum dots (NQDs) offer the exciting prospect of simultaneously manipulating device and material structures and processes to enable more efficient solar energy conversion. Most importantly, these colloidal nanocrystal quantum dots are amenable to inexpensive fabrication techniques such as dip coating or spray coating of the constituent nanoscale materials onto various substrates. This dissertation focuses on the development of nanostructured photovoltaic devices, that exhibit multiple exciton generation, and that exploit the wide absorption spectra enabled by the quantum dots for next generation highly efficient, low cost, solar cells. Firstly, multiple exciton generation and subsequent electrical extraction from a thin film photoconductive device constructed from PbSe NQDs is demonstrated. As an extension of this work, this PbSe NQD photoconductor was used in a tandem structure with a polymer solar cell to demonstrate multiple carrier extraction the application of an external electric field. This structure exhibited improved device durability from UV irradiation due to the self-passivating effect provided by the PbSe layer. In order to achieve better exciton

  5. Printing Processes Used to Manufacture Photovoltaic Solar Cells

    ERIC Educational Resources Information Center

    Rardin, Tina E.; Xu, Renmei

    2011-01-01

    There is a growing need for renewable energy sources, and solar power is a good option in many instances. Photovoltaic solar panels are now being manufactured via various methods, and different printing processes are being incorporated into the manufacturing process. Screen printing has been used most prevalently in the printing process to make…

  6. Dye Sensitized Solar Cells for Economically Viable Photovoltaic Systems.

    PubMed

    Jung, Hyun Suk; Lee, Jung-Kun

    2013-05-16

    TiO2 nanoparticle-based dye sensitized solar cells (DSSCs) have attracted a significant level of scientific and technological interest for their potential as economically viable photovoltaic devices. While DSSCs have multiple benefits such as material abundance, a short energy payback period, constant power output, and compatibility with flexible applications, there are still several challenges that hold back large scale commercialization. Critical factors determining the future of DSSCs involve energy conversion efficiency, long-term stability, and production cost. Continuous advancement of their long-term stability suggests that state-of-the-art DSSCs will operate for over 20 years without a significant decrease in performance. Nevertheless, key questions remain in regards to energy conversion efficiency improvements and material cost reduction. In this Perspective, the present state of the field and the ongoing efforts to address the requirements of DSSCs are summarized with views on the future of DSSCs. PMID:26282979

  7. Concrete Embedded Dye-Synthesized Photovoltaic Solar Cell

    PubMed Central

    Hosseini, T.; Flores-Vivian, I.; Sobolev, K.; Kouklin, N.

    2013-01-01

    This work presents the concept of a monolithic concrete-integrated dye-synthesized photovoltaic solar cell for optical-to-electrical energy conversion and on-site power generation. The transport measurements carried out in the dark revealed the presence of VOC of ~190 mV and ISC of ~9 μA, induced by the electrochemical conversion of concrete-supplied ionic impurities at the electrodes. The current-voltage measurements performed under illumination at incident optical powers of ~46 mW confirmed the generation of electrical power of ~0.64 μW with almost half generated via battery effect. This work presents a first step towards realizing the additional pathways to low-cost electrical power production in urban environments based on a combined use of organic dyes, nanotitania and concrete technology. PMID:24067664

  8. Photovoltaic solar concentrator

    DOEpatents

    Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

    2016-03-15

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  9. Photovoltaic solar concentrator

    DOEpatents

    Nielson, Gregory N.; Okandan, Murat; Resnick, Paul J.; Cruz-Campa, Jose Luis

    2012-12-11

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  10. Space satellite power system. [conversion of solar energy by photovoltaic solar cell arrays

    NASA Technical Reports Server (NTRS)

    Glaser, P. E.

    1974-01-01

    The concept of a satellite solar power station was studied. It is shown that it offers the potential to meet a significant portion of future energy needs, is pollution free, and is sparing of irreplaceable earth resources. Solar energy is converted by photovoltaic solar cell arrays to dc energy which in turn is converted into microwave energy in a large active phased array. The microwave energy is beamed to earth with little attenuation and is converted back to dc energy on the earth. Economic factors are considered.

  11. Solar Thermophotovoltaics: Combining Solar Thermal and Photovoltaics

    NASA Astrophysics Data System (ADS)

    Luque, Antonio

    2007-02-01

    An analysis of ideal solar converters from a thermodynamic point of view is presented that distinguishes between solar thermal and photovoltaic converters. The later do not have hot elements. Ideal solar thermophotovoltaic converters are also described as needing a Carnot machine for operation. The ideal solar cells can be such Carnot machine and therefore a solar thermophotovoltaic converter is a solar thermal converter whose engine is a solar cell. Once hot elements are accepted, several novel modalities of converters are described including thermophotonic converters, combined photovoltaic thermal converters and hot electron converters.

  12. Candidate solar cell materials for photovoltaic conversion in a solar power satellite /SPS/

    NASA Technical Reports Server (NTRS)

    Glaser, P. E.; Almgren, D. W.

    1978-01-01

    In recognition of the obstacles to solar-generated baseload power on earth, proposals have been made to locate solar power satellites in geosynchronous earth orbit (GEO), where solar energy would be available 24 hours a day during most of the time of the year. In an SPS, the electricity produced by solar energy conversion will be fed to microwave generators forming part of a planar phase-array transmitting antenna. The antenna is designed to precisely direct a microwave beam of very low intensity to one or more receiving antennas at desired locations on earth. At the receiving antenna, the microwave energy will be safely and efficiently reconverted to electricity and then be transmitted to consumers. An SPS system will include a number of satellites in GEO. Attention is given to the photovoltaic option for solar energy conversion in GEO, solar cell requirements, the availability of materials, the implication of large production volumes, requirements for high-volume manufacture of solar cell arrays, and the effects of concentration ratio on solar cell array area.

  13. MANUFACTURE OF PHOTOVOLTAIC SOLAR CELL USING PLANT CHLOROPHYLL

    EPA Science Inventory

    To date, we have successfully manufactured working chlorophyll sensitized solar cells using chlorophyll (and b mixture) from spinach leaves. We have evaluated the electronic characteristics (voltage, current, and power outputs using different loading resistors) of this solar c...

  14. Spectral splitting photovoltaics using perovskite and wideband dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Kinoshita, Takumi; Nonomura, Kazuteru; Joong Jeon, Nam; Giordano, Fabrizio; Abate, Antonio; Uchida, Satoshi; Kubo, Takaya; Seok, Sang Il; Nazeeruddin, Mohammad Khaja; Hagfeldt, Anders; Grätzel, Michael; Segawa, Hiroshi

    2015-11-01

    The extension of the light absorption of photovoltaics into the near-infrared region is important to increase the energy conversion efficiency. Although the progress of the lead halide perovskite solar cells is remarkable, and high conversion efficiency of >20% has been reached, their absorption limit on the long-wavelength side is ~800 nm. To further enhance the conversion efficiency of perovskite-based photovoltaics, a hybridized system with near-infrared photovoltaics is a useful approach. Here we report a panchromatic sensitizer, coded DX3, that exhibits a broad response into the near-infrared, up to ~1100 nm, and a photocurrent density exceeding 30 mA cm-2 in simulated air mass 1.5 standard solar radiation. Using the DX3-based dye-sensitized solar cell in conjunction with a perovskite cell that harvests visible light, the hybridized mesoscopic photovoltaics achieved a conversion efficiency of 21.5% using a system of spectral splitting.

  15. EH AND S ANALYSIS OF DYE-SENSITIZED PHOTOVOLTAIC SOLAR CELL PRODUCTION.

    SciTech Connect

    BOWERMAN,B.; FTHENAKIS,V.

    2001-10-01

    Photovoltaic solar cells based on a dye-sensitized nanocrystalline titanium dioxide photoelectrode have been researched and reported since the early 1990's. Commercial production of dye-sensitized photovoltaic solar cells has recently been reported in Australia. In this report, current manufacturing methods are described, and estimates are made of annual chemical use and emissions during production. Environmental, health and safety considerations for handling these materials are discussed. This preliminary EH and S evaluation of dye-sensitized titanium dioxide solar cells indicates that some precautions will be necessary to mitigate hazards that could result in worker exposure. Additional information required for a more complete assessment is identified.

  16. Enhanced photovoltaic performance of an inclined nanowire array solar cell.

    PubMed

    Wu, Yao; Yan, Xin; Zhang, Xia; Ren, Xiaomin

    2015-11-30

    An innovative solar cell based on inclined p-i-n nanowire array is designed and analyzed. The results show that the inclined geometry can sufficiently increase the conversion efficiency of solar cells by enhancing the absorption of light in the active region. By tuning the nanowire array density, nanowire diameter, nanowire length, as well as the proportion of intrinsic region of the inclined nanowire solar cell, a remarkable efficiency in excess of 16% can be obtained in GaAs. Similar results have been obtained in InP and Si nanowire solar cells, demonstrating the universality of the performance enhancement of inclined nanowire arrays. PMID:26698807

  17. Photovoltaics: solar electric power systems

    SciTech Connect

    1980-02-01

    The operation and uses of solar cells and the National Photovoltaic Program are briefly described. Eleven DOE photovoltaic application projects are described including forest lookout towers; Wilcox Memorial Hospital in Hawaii; WBNO daytime AM radio station; Schuchuli Indian Village; Meade, Nebraska, agricultural experiment; Mt. Laguna Air Force Station; public schools and colleges; residential applications; and Sea World of Florida. (WHK)

  18. High-Performance GaAs Nanowire Solar Cells for Flexible and Transparent Photovoltaics.

    PubMed

    Han, Ning; Yang, Zai-xing; Wang, Fengyun; Dong, Guofa; Yip, SenPo; Liang, Xiaoguang; Hung, Tak Fu; Chen, Yunfa; Ho, Johnny C

    2015-09-16

    Among many available photovoltaic technologies at present, gallium arsenide (GaAs) is one of the recognized leaders for performance and reliability; however, it is still a great challenge to achieve cost-effective GaAs solar cells for smart systems such as transparent and flexible photovoltaics. In this study, highly crystalline long GaAs nanowires (NWs) with minimal crystal defects are synthesized economically by chemical vapor deposition and configured into novel Schottky photovoltaic structures by simply using asymmetric Au-Al contacts. Without any doping profiles such as p-n junction and complicated coaxial junction structures, the single NW Schottky device shows a record high apparent energy conversion efficiency of 16% under air mass 1.5 global illumination by normalizing to the projection area of the NW. The corresponding photovoltaic output can be further enhanced by connecting individual cells in series and in parallel as well as by fabricating NW array solar cells via contact printing showing an overall efficiency of 1.6%. Importantly, these Schottky cells can be easily integrated on the glass and plastic substrates for transparent and flexible photovoltaics, which explicitly demonstrate the outstanding versatility and promising perspective of these GaAs NW Schottky photovoltaics for next-generation smart solar energy harvesting devices. PMID:26284305

  19. Design and fabrication of a rectenna system to be coupled to photovoltaic solar cells

    NASA Astrophysics Data System (ADS)

    Mossavat, Mazda

    Inkjet-printed metamaterials and nanotechnology enabled flexible antennas fabricated on glass or polyester substrates help in further absorption of transmitted radiation through photovoltaic solar cells. Using metamaterials processed by inkjet printing and diffusing it, for a rectenna system coupled with photovoltaic solar cells, as rectifying antenna, an antenna in system in tandem is created. Metamaterials are artificial materials engineered to have properties that may not be found in nature (negative refractive index). When used in an antenna, they increase gain. For efficient solar cell use, nanophotonics on the incident surface or metamaterials under it as a rectenna, can enhance voltage gain in cloudy or rainy condition, which in turn increases the overall efficiency and reduces the amount of material required, thereby cutting costs. Photovoltaic is a field of technology and research related to practical application of photovoltaic cells in producing electricity from light. Cells are described as photovoltaic cells when the light source is not necessarily sunlight but can be lamplight, artificial light, or any other source used for detecting light or other electromagnetic radiation at different light intensity and producing voltage. These can be, for example, infrared detectors, or detectors for measurement of light intensity. Conventional solar cell films are typically manufactured using expensive and slow manufacturing methods, which rely on high-temperature fabrication and finicky `vacuum deposition' processes for depositing solar materials onto substrates (III-V elements). The resultant products are simply too thick to allow for transparency. An important consideration in the development of a commercially viable solar powered cell is the glass substrate. The learning process and skills involved in developing the antenna below a solar cell is a great experience in theory and practice. My main effort will be to design and check performance of different

  20. Low cost silicon-on-ceramic photovoltaic solar cells

    NASA Technical Reports Server (NTRS)

    Koepke, B. G.; Heaps, J. D.; Grung, B. L.; Zook, J. D.; Sibold, J. D.; Leipold, M. H.

    1980-01-01

    A technique has been developed for coating low-cost mullite-based refractory substrates with thin layers of solar cell quality silicon. The technique involves first carbonizing one surface of the ceramic and then contacting it with molten silicon. The silicon wets the carbonized surface and, under the proper thermal conditions, solidifies as a large-grained sheet. Solar cells produced from this composite silicon-on-ceramic material have exhibited total area conversion efficiencies of ten percent.

  1. Simple Photovoltaic Cells for Exploring Solar Energy Concepts

    ERIC Educational Resources Information Center

    Appleyard, S. J.

    2006-01-01

    Low-efficiency solar cells for educational purposes can be simply made in school or home environments using wet-chemistry techniques and readily available chemicals of generally low toxicity. Instructions are given for making solar cells based on the heterojunctions Cu/Cu[subscript 2]O, Cu[subscript 2]O/ZnO and Cu[subscript 2]S/ZnO, together with…

  2. Solar cell array design handbook - The principles and technology of photovoltaic energy conversion

    NASA Technical Reports Server (NTRS)

    Rauschenbach, H. S.

    1980-01-01

    Photovoltaic solar cell array design and technology for ground-based and space applications are discussed from the user's point of view. Solar array systems are described, with attention given to array concepts, historical development, applications and performance, and the analysis of array characteristics, circuits, components, performance and reliability is examined. Aspects of solar cell array design considered include the design process, photovoltaic system and detailed array design, and the design of array thermal, radiation shielding and electromagnetic components. Attention is then given to the characteristics and design of the separate components of solar arrays, including the solar cells, optical elements and mechanical elements, and the fabrication, testing, environmental conditions and effects and material properties of arrays and their components are discussed.

  3. Photovoltaic cell

    DOEpatents

    Gordon, Roy G.; Kurtz, Sarah

    1984-11-27

    In a photovoltaic cell structure containing a visibly transparent, electrically conductive first layer of metal oxide, and a light-absorbing semiconductive photovoltaic second layer, the improvement comprising a thin layer of transition metal nitride, carbide or boride interposed between said first and second layers.

  4. Low-cost photovoltaics: Luminescent solar concentrators and colloidal quantum dot solar cells

    NASA Astrophysics Data System (ADS)

    Leow, Shin Woei

    Solar energy has long been lauded as an inexhaustible fuel source with more energy reaching the earth's surface in one hour than the global consumption for a year. Although capable of satisfying the world's energy requirements, solar energy remains an expensive technology that has yet to attain grid parity. Another drawback is that existing solar farms require large quantities of land in order to generate power at useful rates. In this work, we look to luminescent solar concentrator systems and quantum dot technology as viable solutions to lowering the cost of solar electricity production with the flexibility to integrate such technologies into buildings to achieve dual land use. Luminescent solar concentrator (LSC) windows with front-facing photovoltaic (PV) cells were built and their gain and power efficiency were investigated. Conventional LSCs employ a photovoltaic (PV) cell that is placed on the edge of the LSC, facing inward. This work describes a new design with the PV cells on the front-face allowing them to receive both direct solar irradiation and wave-guided photons emitted from a dye embedded in an acrylic sheet, which is optically coupled to the PV cells. Parameters investigated include the thickness of the waveguide, edge treatment of the window, cell width, and cell placement. The data allowed us to make projections that aided in designing windows for maximized overall efficiency. A gain in power of 2.2x over the PV cells alone was obtained with PV cell coverage of 5%, and a power conversion efficiency as high as 6.8% was obtained with a PV cell coverage of 31%. Balancing the trade-offs between gain and efficiency, the design with the lowest cost per watt attained a power efficiency of 3.8% and a gain of 1.6x. With the viability of the LSC demonstrated, a weighted Monte-Carlo Ray Tracing program was developed to study the transport of photons and loss mechanisms in the LSC to aid in design optimization. The program imports measured absorption

  5. Ferroelectric-semiconductor photovoltaics: Non-PN junction solar cells

    NASA Astrophysics Data System (ADS)

    Liu, Fude; Wang, Wentao; Wang, Lei; Yang, Guandong

    2014-03-01

    Traditional positive-negative (PN) junction based solar cells have many limitations. Herein, we introduce ferroelectric-semiconductor solar cells that use the bound surface charges of the ferroelectric for achieving charge separation in the semiconductor. The feasibility of the new concept cells was verified both experimentally and theoretically in detail. The new cells are unique in that free charge carriers and fixed charge carriers are physically separated from each other. The feature allows us to go beyond traditional junction-based structures and have more freedom in material selection, device design, and fabrication.

  6. The effect of the low Earth orbit environment on space solar cells: Results of the Advanced Photovoltaic Experiment (S0014)

    NASA Technical Reports Server (NTRS)

    Brinker, David J.; Hickey, John R.; Scheiman, David A.

    1993-01-01

    The results of post-flight performance testing of the solar cells flown on the Advanced Photovoltaic Experiment are reported. Comparison of post-flight current-voltage characteristics with similar pre-flight data revealed little or no change in solar cell conversion efficiency, confirming the reliability and endurance of space photovoltaic cells. This finding is in agreement with the lack of significant physical changes in the solar cells despite nearly six years in the low Earth orbit environment.

  7. Considerably improved photovoltaic performance of carbon nanotube-based solar cells using metal oxide layers

    NASA Astrophysics Data System (ADS)

    Wang, Feijiu; Kozawa, Daichi; Miyauchi, Yuhei; Hiraoka, Kazushi; Mouri, Shinichiro; Ohno, Yutaka; Matsuda, Kazunari

    2015-02-01

    Carbon nanotube-based solar cells have been extensively studied from the perspective of potential application. Here we demonstrated a significant improvement of the carbon nanotube solar cells by the use of metal oxide layers for efficient carrier transport. The metal oxides also serve as an antireflection layer and an efficient carrier dopant, leading to a reduction in the loss of the incident solar light and an increase in the photocurrent, respectively. As a consequence, the photovoltaic performance of both p-single-walled carbon nanotube (SWNT)/n-Si and n-SWNT/p-Si heterojunction solar cells using MoOx and ZnO layers is improved, resulting in very high photovoltaic conversion efficiencies of 17.0 and 4.0%, respectively. These findings regarding the use of metal oxides as multifunctional layers suggest that metal oxide layers could improve the performance of various electronic devices based on carbon nanotubes.

  8. Considerably improved photovoltaic performance of carbon nanotube-based solar cells using metal oxide layers.

    PubMed

    Wang, Feijiu; Kozawa, Daichi; Miyauchi, Yuhei; Hiraoka, Kazushi; Mouri, Shinichiro; Ohno, Yutaka; Matsuda, Kazunari

    2015-01-01

    Carbon nanotube-based solar cells have been extensively studied from the perspective of potential application. Here we demonstrated a significant improvement of the carbon nanotube solar cells by the use of metal oxide layers for efficient carrier transport. The metal oxides also serve as an antireflection layer and an efficient carrier dopant, leading to a reduction in the loss of the incident solar light and an increase in the photocurrent, respectively. As a consequence, the photovoltaic performance of both p-single-walled carbon nanotube (SWNT)/n-Si and n-SWNT/p-Si heterojunction solar cells using MoOx and ZnO layers is improved, resulting in very high photovoltaic conversion efficiencies of 17.0 and 4.0%, respectively. These findings regarding the use of metal oxides as multifunctional layers suggest that metal oxide layers could improve the performance of various electronic devices based on carbon nanotubes. PMID:25692264

  9. Silicon solar photovoltaic power stations

    NASA Technical Reports Server (NTRS)

    Chowaniec, C. R.; Ferber, R. R.; Pittman, P. F.; Marshall, B. W.

    1977-01-01

    Modular design of components and arrays, cost estimates for modules and support structures, and cost/performance analysis of a central solar photovoltaic power plant are discussed. Costs of collector/reflector arrays are judged the dominant element in the total capital investment. High-concentration solar tracking arrays are recommended as the most economic means for producing solar photovoltaic energy when solar cells costs are high ($500 per kW generated). Capital costs for power conditioning subsystem components are itemized and system busbar energy costs are discussed at length.

  10. The electrodeposition of multilayers on a polymeric substrate in flexible organic photovoltaic solar cells

    NASA Astrophysics Data System (ADS)

    Guedes, Andre F. S.; Guedes, Vilmar P.; Souza, Monica L.; Tartari, Simone; Cunha, Idaulo J.

    2015-09-01

    Flexible organic photovoltaic solar cells have drawn intense attention due to their advantages over competing solar cell technologies. The method utilized to deposit as well as to integrate solutions and processed materials, manufacturing organic solar cells by the Electrodeposition System, has been presented in this research. In addition, we have demonstrated a successful integration of a process for manufacturing the flexible organic solar cell prototype and we have discussed on the factors that make this process possible. The maximum process temperature was 120°C, which corresponds to the baking of the active polymeric layer. Moreover, the new process of the Electrodeposition of complementary active layer is based on the application of voltage versus time in order to obtain a homogeneous layer with thin film. This thin film was not only obtained by the electrodeposition of PANI-X1 on P3HT/PCBM Blend, but also prepared in perchloric acid solution. Furthermore, these flexible organic photovoltaic solar cells presented power conversion efficiency of 12% and the inclusion of the PANI-X1 layer reduced the effects of degradation on these organic photovoltaic panels induced by solar irradiation. Thus, in the Scanning Electron Microscopy (SEM), these studies have revealed that the surface of PANI-X1 layers is strongly conditioned by the dielectric surface morphology.

  11. See-through dye-sensitized solar cells: photonic reflectors for tandem and building integrated photovoltaics.

    PubMed

    Heiniger, Leo-Philipp; O'Brien, Paul G; Soheilnia, Navid; Yang, Yang; Kherani, Nazir P; Grätzel, Michael; Ozin, Geoffrey A; Tétreault, Nicolas

    2013-10-25

    See-through dye-sensitized solar cells with 1D photonic crystal Bragg reflector photoanodes show an increase in peak external quantum efficiency of 47% while still maintaining high fill factors, resulting in an almost 40% increase in power conversion efficiency. These photoanodes are ideally suited for tandem and building integrated photovoltaics. PMID:23966106

  12. Low-cost photovoltaics: Luminescent solar concentrators and colloidal quantum dot solar cells

    NASA Astrophysics Data System (ADS)

    Leow, Shin Woei

    Solar energy has long been lauded as an inexhaustible fuel source with more energy reaching the earth's surface in one hour than the global consumption for a year. Although capable of satisfying the world's energy requirements, solar energy remains an expensive technology that has yet to attain grid parity. Another drawback is that existing solar farms require large quantities of land in order to generate power at useful rates. In this work, we look to luminescent solar concentrator systems and quantum dot technology as viable solutions to lowering the cost of solar electricity production with the flexibility to integrate such technologies into buildings to achieve dual land use. Luminescent solar concentrator (LSC) windows with front-facing photovoltaic (PV) cells were built and their gain and power efficiency were investigated. Conventional LSCs employ a photovoltaic (PV) cell that is placed on the edge of the LSC, facing inward. This work describes a new design with the PV cells on the front-face allowing them to receive both direct solar irradiation and wave-guided photons emitted from a dye embedded in an acrylic sheet, which is optically coupled to the PV cells. Parameters investigated include the thickness of the waveguide, edge treatment of the window, cell width, and cell placement. The data allowed us to make projections that aided in designing windows for maximized overall efficiency. A gain in power of 2.2x over the PV cells alone was obtained with PV cell coverage of 5%, and a power conversion efficiency as high as 6.8% was obtained with a PV cell coverage of 31%. Balancing the trade-offs between gain and efficiency, the design with the lowest cost per watt attained a power efficiency of 3.8% and a gain of 1.6x. With the viability of the LSC demonstrated, a weighted Monte-Carlo Ray Tracing program was developed to study the transport of photons and loss mechanisms in the LSC to aid in design optimization. The program imports measured absorption

  13. Solar Photovoltaic Energy.

    ERIC Educational Resources Information Center

    Ehrenreich, Henry; Martin, John H.

    1979-01-01

    The goals of solar photovoltaic technology in contributing to America's future energy needs are presented in this study conducted by the American Physical Society. Although the time needed for photovoltaics to become popular is several decades away, according to the author, short-range applications are given. (Author/SA)

  14. Planar photovoltaic solar concentrator module

    DOEpatents

    Chiang, Clement J.

    1992-01-01

    A planar photovoltaic concentrator module for producing an electrical signal from incident solar radiation includes an electrically insulating housing having a front wall, an opposing back wall and a hollow interior. A solar cell having electrical terminals is positioned within the interior of the housing. A planar conductor is connected with a terminal of the solar cell of the same polarity. A lens forming the front wall of the housing is operable to direct solar radiation incident to the lens into the interior of the housing. A refractive optical element in contact with the solar cell and facing the lens receives the solar radiation directed into the interior of the housing by the lens and directs the solar radiation to the solar cell to cause the solar cell to generate an electrical signal. An electrically conductive planar member is positioned in the housing to rest on the housing back wall in supporting relation with the solar cell terminal of opposite polarity. The planar member is operable to dissipate heat radiated by the solar cell as the solar cell generates an electrical signal and further forms a solar cell conductor connected with the solar cell terminal to permit the electrical signal generated by the solar cell to be measured between the planar member and the conductor.

  15. Planar photovoltaic solar concentrator module

    DOEpatents

    Chiang, C.J.

    1992-12-01

    A planar photovoltaic concentrator module for producing an electrical signal from incident solar radiation includes an electrically insulating housing having a front wall, an opposing back wall and a hollow interior. A solar cell having electrical terminals is positioned within the interior of the housing. A planar conductor is connected with a terminal of the solar cell of the same polarity. A lens forming the front wall of the housing is operable to direct solar radiation incident to the lens into the interior of the housing. A refractive optical element in contact with the solar cell and facing the lens receives the solar radiation directed into the interior of the housing by the lens and directs the solar radiation to the solar cell to cause the solar cell to generate an electrical signal. An electrically conductive planar member is positioned in the housing to rest on the housing back wall in supporting relation with the solar cell terminal of opposite polarity. The planar member is operable to dissipate heat radiated by the solar cell as the solar cell generates an electrical signal and further forms a solar cell conductor connected with the solar cell terminal to permit the electrical signal generated by the solar cell to be measured between the planar member and the conductor. 5 figs.

  16. Photovoltaic characteristics of diffused P/+N bulk GaAs solar cells

    NASA Technical Reports Server (NTRS)

    Borrego, J. M.; Keeney, R. P.; Bhat, I. B.; Bhat, K. N.; Sundaram, L. G.; Ghandhi, S. K.

    1982-01-01

    The photovoltaic characteristics of P(+)N junction solar cells fabricated on bulk GaAs by an open tube diffusion technique are described in this paper.Spectral response measurements were analyzed in detail and compared to a computer simulation in order to determine important material parameters. It is projected that proper optimization of the cell parameters can increase the efficiency of the cells from 12.2 percent to close to 20 percent.

  17. Solar energy conversion by dye-sensitized photovoltaic cells.

    PubMed

    Grätzel, Michael

    2005-10-01

    The quality of human life depends to a large degree on the availability of energy. This is threatened unless renewable energy resources can be developed in the near future. Chemistry is expected to make important contributions to identify environmentally friendly solutions of the energy problem. One attractive strategy discussed in this Forum Article is the development of solar cells that are based on the sensitization of mesoscopic oxide films by dyes or quantum dots. These systems have already reached conversion efficiencies exceeding 11%. The underlying fundamental processes of light harvesting by the sensitizer, heterogeneous electron transfer from the electronically excited chromophore into the conduction band of the semiconductor oxide, and percolative migration of the injected electrons through the mesoporous film to the collector electrode will be described below in detail. A number of research topics will also be discussed, and the examples for the first outdoor application of such solar cells will be provided. PMID:16180840

  18. Photovoltaic cell

    SciTech Connect

    Bronstein-Bonte, I.Y.; Fischer, A.B.

    1986-12-16

    This patent describes a product comprising a photovoltaic cell including a luminescent dye which will absorb radiation at a wavelength to which the cell is not significantly responsive and emit radiation at a higher wavelength at which it is responsive. The improvement described here is wherein the dye comprises a lepidopterene.

  19. The high intensity solar cell: Key to low cost photovoltaic power

    NASA Technical Reports Server (NTRS)

    Sater, B. L.; Goradia, C.

    1975-01-01

    The design considerations and performance characteristics of the 'high intensity' (HI) solar cell are presented. A high intensity solar system was analyzed to determine its cost effectiveness and to assess the benefits of further improving HI cell efficiency. It is shown that residential sized systems can be produced at less than $1000/kW peak electric power. Due to their superior high intensity performance characteristics compared to the conventional and VMJ cells, HI cells and light concentrators may be the key to low cost photovoltaic power.

  20. Quantum Dot Sensitized Nanotubes for Full Solar Spectrum Photovoltaic Cell

    NASA Astrophysics Data System (ADS)

    Khanal, Sohana

    The demand for energy with limited non-renewable sources of energy has called researchers to find clean renewable energy sources. Solar light is considered good choice of the alternate energy. Our effort in this work was to investigate efficient photovoltaic (PV) systems by designing a hybrid photoelectrode with good absorption as well as charge transport properties. A coupled semiconductor material, one-dimensional TiO2 nanotubes (1D TiO2-NTs), filled with low band semiconductor quantum dots (QDs), PbS QDs, for better charge carrier transport was prepared and investigated. The vertically standing self assembled nanotubular array was attained by anodizing the Ti metal in two different solutions: (1) Ethylene Glycol with 0.5 wt% NH4F and 3 vol percent water and (2) 0.5M H3PO4 with 0.5 wt% NH4F. The anodized samples were annealed and then filled with the nanoparticles of other low band gap semiconductor materials. The CdS nanoparticles were used for the better understanding of the sensitizing process. The material was then switched to the PbS. As in the hypothesis, if PbS quantum dots are uniformly distributed in the 1D TiO2 Multiple Charge Carrier Generation can be created since PbS has a small band gap. A chemical bath deposition process in the presence of ultrasonic waves was adopted for the deposition of the QDs. Saturated lead sulfide solution was used as the lead source and the 0.2 M Na2S solution for the sulfur source. The process resulted in the successful uniform deposition of the PbS QDs onto the 1D TiO2 NTs. The deposited compound obeyed the stoichiometric ratio of 1:1 as desired. Photocurrent densities of 4.5 mA/cm2 was obtained, which is higher than the TiO2 alone in a polysulfide solution. PbS-TiO2 can be a suitable candidate for harvesting a broad solar spectrum as the UV-vis study proved that they absorb the light in the UV range.

  1. Spectral splitting photovoltaics using perovskite and wideband dye-sensitized solar cells

    PubMed Central

    Kinoshita, Takumi; Nonomura, Kazuteru; Joong Jeon, Nam; Giordano, Fabrizio; Abate, Antonio; Uchida, Satoshi; Kubo, Takaya; Seok, Sang Il; Nazeeruddin, Mohammad Khaja; Hagfeldt, Anders; Grätzel, Michael; Segawa, Hiroshi

    2015-01-01

    The extension of the light absorption of photovoltaics into the near-infrared region is important to increase the energy conversion efficiency. Although the progress of the lead halide perovskite solar cells is remarkable, and high conversion efficiency of >20% has been reached, their absorption limit on the long-wavelength side is ∼800 nm. To further enhance the conversion efficiency of perovskite-based photovoltaics, a hybridized system with near-infrared photovoltaics is a useful approach. Here we report a panchromatic sensitizer, coded DX3, that exhibits a broad response into the near-infrared, up to ∼1100 nm, and a photocurrent density exceeding 30 mA cm−2 in simulated air mass 1.5 standard solar radiation. Using the DX3-based dye-sensitized solar cell in conjunction with a perovskite cell that harvests visible light, the hybridized mesoscopic photovoltaics achieved a conversion efficiency of 21.5% using a system of spectral splitting. PMID:26538097

  2. Photovoltaic Engineering Testbed: A Facility for Space Calibration and Measurement of Solar Cells on the International Space Station

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Bailey, Sheila G.; Jenkins, Phillip; Sexton, J. Andrew; Scheiman, David; Christie, Robert; Charpie, James; Gerber, Scott S.; Johnson, D. Bruce

    2001-01-01

    The Photovoltaic Engineering Testbed ("PET") is a facility to be flown on the International Space Station to perform calibration, measurement, and qualification of solar cells in the space environment and then returning the cells to Earth for laboratory use. PET will allow rapid turnaround testing of new photovoltaic technology under AM0 conditions.

  3. New nonimaging static concentrators for bifacial photovoltaic solar cells

    NASA Astrophysics Data System (ADS)

    Benitez, Pablo; Hernandez, Maikel; Mohedano Arroyo, Ruben; Minano, Juan C.; Munoz, Fernando

    1999-10-01

    Two new static nonimaging designs for bifacial solar cells are presented. These concentrators have been obtained with the Simultaneous Multiple Surface design method of Nonimaging Optics. The main characteristics of these concentrators are: (1) high compactness, (2) linear symmetry (in order to be made by low cost extrusion), (3) performance close to the thermodynamic limit, and (4) a non-shading sizable gap between at least one of the cell edges and the optically active surfaces. This last feature is interesting because this gap can be used to allocate the interconnections between cells, with no additional optical losses. As an example of the results, one design for an acceptable angle of +/- 30 degrees gets a geometrical concentration of 5.5X, with an average thickness to entry aperture width ratio of 0.24. The 3D ray-tracing analysis of the concentrators is also presented.

  4. High temperature solid oxide regenerative fuel cell for solar photovoltaic energy storage

    NASA Technical Reports Server (NTRS)

    Bents, David J.

    1987-01-01

    A hydrogen-oxygen regenerative fuel cell (RFC) energy storage system based on high temperature solid oxide fuel cell (SOFC) technology is described. The reactants are stored as gases in lightweight insulated pressure vessels. The product water is stored as a liquid in saturated equilibrium with the fuel gas. The system functions as a secondary battery and is applicable to darkside energy storage for solar photovoltaics.

  5. Light-splitting photovoltaic system utilizing two dual-junction solar cells

    SciTech Connect

    Xiong, Kanglin; Yang, Hui; Lu, Shulong; Dong, Jianrong; Zhou, Taofei; Wang, Rongxin; Jiang, Desheng

    2010-12-15

    There are many difficulties limiting the further development of monolithic multi-junction solar cells, such as the growth of lattice-mismatched material and the current matching constraint. As an alternative approach, the light-splitting photovoltaic system is investigated intensively in different aspects, including the energy loss mechanism and the choice of energy bandgaps of solar cells. Based on the investigation, a two-dual junction system has been implemented employing lattice-matched GaInP/GaAs and InGaAsP/InGaAs cells grown epitaxially on GaAs and InP substrates, respectively. (author)

  6. Perovskite photovoltaics: a high-efficiency newcomer to the solar cell family

    NASA Astrophysics Data System (ADS)

    Wang, Baohua; Xiao, Xudong; Chen, Tao

    2014-10-01

    Organometal trihalide perovskite-based light absorbers have attracted great attention due to their excellent photovoltaic properties. The swift developments in the device fabrication techniques have led to the power conversion efficiencies exceeding 17%. In this minireview, we will present the typical characteristics of the materials and device structures, followed by analysing updated understandings on the operational principles of the devices. We will also point out the outstanding issues regarding the materials and devices. Finally, as a high-efficiency newcomer to the solar cell family, the potential impact on the relevant photovoltaics will be discussed.

  7. Enhanced Photovoltaic Performance with Carbon Nanotubes Incorporating into Hole Transport Materials for Perovskite Solar Cells

    NASA Astrophysics Data System (ADS)

    Wang, Junxia; Li, Jingling; Xu, Xueqing; Xu, Gang; Shen, Honglie

    2016-06-01

    In an attempt to further enhance the photovoltaic performance of perovskite solar cells (PSCs) fabricated by spray deposition under ambient conditions, carbon nanotubes (CNTs) are introduced for incorporation into hole transport materials (HTM). The effect of CNT category and length on the efficiency of the perovskite solar cell for incorporation into HTM is investigated. The enhanced photovoltaic performance is achieved in multi-walled carbon nanotubes (MWCNTs) with the shortest length. The efficiency of acid-treated MWCNT-based cells is improved compared to that of purified MWCNTs due to the better dispersibility and the π-π interaction between the -COOH group and spiro-OMeTAD. As the volume ratio of the spiro-OMeTAD and spiro/MWCNTs mixture is 2:2 or 3:1, the highest power conversion efficiency (PCE) of PSCs containing MWCNTs reaches 8.7% with the enhanced short-circuit current density (J sc) and open-circuit voltage (V oc).

  8. Metal induced crystallization of amorphous silicon for photovoltaic solar cells

    NASA Astrophysics Data System (ADS)

    Van Gestel, D.; Gordon, I.; Poortmans, J.

    A silicon thin-film technology could lead to less expensive modules by the use of less silicon material and by the implementation of monolithic module processes. A technology based on polycrystalline-silicon thin-films with a grain size between 1 μm and 1 mm (pc-Si), seems particularly promising since it combines the low-cost potential of a thin-film technology with the high efficiency potential of crystalline silicon. One of the possible approaches to fabricate pc-Si absorber layers is metal induced crystallization (MIC). For solar cell applications mainly aluminium is investigated as metal because 1) it forms a eutectic system with silicon instead of a silicide-metal system like e.g. Ni 2) only shallow level defects are formed in the forbidden bandgap of silicon and 3) a layer exchange process can be obtained in combination with a-Si. Aluminum induced crystallization (AIC) of a-Si on non-silicon substrates can results in grains with a preferential (100) orientation and a maximum grain sizes above 50 micrometer. These layers can act as seed layers for further epitaxial growth. Based on this two-step approach (AIC + epitaxial growth) we made solar cells with an energy conversion efficiency of 8%. Based on TEM, EBIC, SEM, defect etch and EBSD measurements we showed that the efficiency is nowadays mainly limited by the presence of electrical intragrain defects.

  9. Enhanced EOS photovoltaic power system capability with InP solar cells

    NASA Technical Reports Server (NTRS)

    Bailey, Sheila G.; Weinberg, Irving; Flood, Dennis J.

    1991-01-01

    The Earth Observing System (EOS), which is part of the International Mission to Planet Earth, is NASA's main contribution to the Global Change Research Program which opens a new era in international cooperation to study the Earth's environment. Five large platforms are to be launched into polar orbit, two by NASA, two by ESA, and one by the Japanese. In such an orbit the radiation resistance of indium phosphide solar cells combined with the potential of utilizing five micron cell structures yields an increase of 10 percent in the payload capability. If further combined with the advanced photovoltaic solar array the payload savings approaches 12 percent.

  10. Solar-cell interconnect design for terrestrial photovoltaic modules

    NASA Technical Reports Server (NTRS)

    Mon, G. R.; Moore, D. M.; Ross, R. G., Jr.

    1984-01-01

    Useful solar cell interconnect reliability design and life prediction algorithms are presented, together with experimental data indicating that the classical strain cycle (fatigue) curve for the interconnect material does not account for the statistical scatter that is required in reliability predictions. This shortcoming is presently addressed by fitting a functional form to experimental cumulative interconnect failure rate data, which thereby yields statistical fatigue curves enabling not only the prediction of cumulative interconnect failures during the design life of an array field, but also the quantitative interpretation of data from accelerated thermal cycling tests. Optimal interconnect cost reliability design algorithms are also derived which may allow the minimization of energy cost over the design life of the array field.

  11. Solar-cell interconnect design for terrestrial photovoltaic modules

    NASA Astrophysics Data System (ADS)

    Mon, G. R.; Moore, D. M.; Ross, R. G., Jr.

    1984-11-01

    Useful solar cell interconnect reliability design and life prediction algorithms are presented, together with experimental data indicating that the classical strain cycle (fatigue) curve for the interconnect material does not account for the statistical scatter that is required in reliability predictions. This shortcoming is presently addressed by fitting a functional form to experimental cumulative interconnect failure rate data, which thereby yields statistical fatigue curves enabling not only the prediction of cumulative interconnect failures during the design life of an array field, but also the quantitative interpretation of data from accelerated thermal cycling tests. Optimal interconnect cost reliability design algorithms are also derived which may allow the minimization of energy cost over the design life of the array field.

  12. Structures and photovoltaic properties of copper oxides/fullerene solar cells

    NASA Astrophysics Data System (ADS)

    Oku, Takeo; Motoyoshi, Ryosuke; Fujimoto, Kazuya; Akiyama, Tsuyoshi; Jeyadevan, Balachandran; Cuya, John

    2011-11-01

    Copper oxide (CuOx) thin films were produced by spin-coating and electrodeposition methods, and their microstructures and photovoltaic properties were investigated. Thin film solar cells based on the Cu2O/C60 and CuO/C60 heterojunction or bulk heterojunction structures were fabricated on F-doped or In-doped SnO2, which showed photovoltaic activity under air mass 1.5 simulated sunlight conditions. Microstructures of the CuOx thin films were examined by X-ray diffraction and transmission electron microscopy, which indicated the presence of Cu2O and CuO nanoparticles. The energy levels of the present solar cells were also discussed.

  13. Enhancing photovoltaic efficiency through radiative cooling of solar cells below ambient temperature

    NASA Astrophysics Data System (ADS)

    Safi, Taqiyyah; Munday, Jeremy

    Sunlight heats up solar cells and the resulting elevated solar cell temperature adversely effects the photovoltaic efficiency and the reliability of the cell. Currently, a variety of active and passive cooling strategies are used to lower the operating temperature of the solar cell. Passive radiative cooling requires no energy input, and is ideal for solar cells; however, previously demonstrated devices still operate above the ambient, leading to a lower efficiency as compared to the ideal Shockley-Queisser limit, which is defined for a cell in contact with an ideal heat sink at ambient temperature (300 K). In this talk, we will describe the use of radiative cooling techniques to lower the cell temperature below the ambient temperature. We show that by combining specifically designed radiative cooling structures with solar cells, efficiencies higher than the limiting efficiency achievable at 300 K can be obtained for solar cells in both terrestrial and extraterrestrial environments. We show that these structures yield an efficiency 0.87% higher than a typical PV module at operating temperatures in a terrestrial application. We also demonstrate an efficiency advantage of 0.4-2.6% for cells in an extraterrestrial environment in near-earth orbit.

  14. Flat plate vs. concentrator solar photovoltaic cells - A manufacturing cost analysis

    NASA Technical Reports Server (NTRS)

    Granon, L. A.; Coleman, M. G.

    1980-01-01

    The choice of which photovoltaic system (flat plate or concentrator) to use for utilizing solar cells to generate electricity depends mainly on the cost. A detailed, comparative manufacturing cost analysis of the two types of systems is presented. Several common assumptions, i.e., cell thickness, interest rate, power rate, factory production life, polysilicon cost, and direct labor rate are utilized in this analysis. Process sequences, cost variables, and sensitivity analyses have been studied, and results of the latter show that the most important parameters which determine manufacturing costs are concentration ratio, manufacturing volume, and cell efficiency. The total cost per watt of the flat plate solar cell is $1.45, and that of the concentrator solar cell is $1.85, the higher cost being due to the increased process complexity and material costs.

  15. Nature of photovoltaic action in dye-sensitized solar cells

    SciTech Connect

    Cahen, D.; Hodes, G.; Graetzel, M.; Guillemoles, J.F.; Riess, I.

    2000-03-09

    The authors explain the cause for the photocurrent and photovoltage in nanocrystalline, mesoporous dye-sensitized solar cells, in terms of the separation, recombination, and transport of electronic charge as well as in terms of electron energetics. On the basis of available experimental data, the basic cause for the photovoltage was confirmed as the change in the electron concentration in the nanocrystalline electron conductor that results from photoinduced charge injection from the dye. The maximum photovoltage is given by the difference in electron energies between the redox level and the bottom of the electron conductor's conduction band, rather than by any difference in electrical potential in the cell, in the dark. Charge separation occurs because of the energetic and entropic driving forces that exist at the dye/electron conductor interface, with charge transport aided by such driving forces at the electron conductor-contact interface. The mesoporosity and nanocrystallinity of the semiconductor are important not only because of the large amount of dye that can be adsorbed on the system's very large surface, but also for two additional reasons: (1) it allows the semiconductor small particles to become almost totally depleted upon immersion in the electrolyte (allowing for large photovoltages), and (2) the proximity of the electrolyte to all particles modes screening of injected electrons, and thus their transport, possible.

  16. III-V Multi-junction solar cells and concentrating photovoltaic (CPV) systems

    NASA Astrophysics Data System (ADS)

    Philipps, Simon P.; Bett, Andreas W.

    2014-12-01

    It has been proven that the only realistic path to practical ultra-high efficiency solar cells is the monolithic multi-junction approach, i.e., to stack pn-junctions made of different semiconductor materials on top of each other. Each sub pn-junction, i.e., sub solar cell, converts a specific part of the sun's spectrum. In this way, the energy of the sunlight photons is converted with low thermalization losses. However, large-area multi-junction solar cells are still far too expensive if applied in standard PV modules. A viable solution to solve the cost issue is to use tiny solar cells in combination with optical concentrating technology, in particular, high concentrating photovoltaics (HCPV), in which the light is concentrated over the solar cells more than 500 times. The combination of ultra-high efficient solar cells and optical concentration lead to low cost on system level and eventually to low levelized cost of electricity, today, well below 8 €cent/kWh and, in the near future, below 5 €cent/kWh. A wide variety of approaches exists for III-V multi-junction solar cells and HCPV systems. This article is intended to provide an overview about the different routes being followed.

  17. Photovoltaic switching mechanism in lateral structure hybrid perovskite solar cells

    SciTech Connect

    Yuan, Yongbo; Chae, Jungseok; Shao, Yuchuan; Wang, Qi; Xiao, Zhengguo; Centrone, Andrea; Huang, Jinsong

    2015-06-05

    In this study, long range electromigration of methylammonium ions (MA+) in methyl ammonium lead tri-iodide (MAPbI3) film is observed directly using the photo­thermal induced resonance technique. The electromigration of MA+ leads to the formation of a lateral p-i-n structure, which is the origin of the switchable photovoltaic effect in MAPbI3 perovskite devices.

  18. Photovoltaic switching mechanism in lateral structure hybrid perovskite solar cells

    DOE PAGESBeta

    Yuan, Yongbo; Chae, Jungseok; Shao, Yuchuan; Wang, Qi; Xiao, Zhengguo; Centrone, Andrea; Huang, Jinsong

    2015-06-05

    In this study, long range electromigration of methylammonium ions (MA+) in methyl ammonium lead tri-iodide (MAPbI3) film is observed directly using the photo­thermal induced resonance technique. The electromigration of MA+ leads to the formation of a lateral p-i-n structure, which is the origin of the switchable photovoltaic effect in MAPbI3 perovskite devices.

  19. Fatigue degradation and electric recovery in Silicon solar cells embedded in photovoltaic modules

    PubMed Central

    Paggi, Marco; Berardone, Irene; Infuso, Andrea; Corrado, Mauro

    2014-01-01

    Cracking in Silicon solar cells is an important factor for the electrical power-loss of photovoltaic modules. Simple geometrical criteria identifying the amount of inactive cell areas depending on the position of cracks with respect to the main electric conductors have been proposed in the literature to predict worst case scenarios. Here we present an experimental study based on the electroluminescence (EL) technique showing that crack propagation in monocrystalline Silicon cells embedded in photovoltaic (PV) modules is a much more complex phenomenon. In spite of the very brittle nature of Silicon, due to the action of the encapsulating polymer and residual thermo-elastic stresses, cracked regions can recover the electric conductivity during mechanical unloading due to crack closure. During cyclic bending, fatigue degradation is reported. This pinpoints the importance of reducing cyclic stresses caused by vibrations due to transportation and use, in order to limit the effect of cracking in Silicon cells. PMID:24675974

  20. Fatigue degradation and electric recovery in Silicon solar cells embedded in photovoltaic modules.

    PubMed

    Paggi, Marco; Berardone, Irene; Infuso, Andrea; Corrado, Mauro

    2014-01-01

    Cracking in Silicon solar cells is an important factor for the electrical power-loss of photovoltaic modules. Simple geometrical criteria identifying the amount of inactive cell areas depending on the position of cracks with respect to the main electric conductors have been proposed in the literature to predict worst case scenarios. Here we present an experimental study based on the electroluminescence (EL) technique showing that crack propagation in monocrystalline Silicon cells embedded in photovoltaic (PV) modules is a much more complex phenomenon. In spite of the very brittle nature of Silicon, due to the action of the encapsulating polymer and residual thermo-elastic stresses, cracked regions can recover the electric conductivity during mechanical unloading due to crack closure. During cyclic bending, fatigue degradation is reported. This pinpoints the importance of reducing cyclic stresses caused by vibrations due to transportation and use, in order to limit the effect of cracking in Silicon cells. PMID:24675974

  1. Advanced photovoltaic solar array development

    NASA Technical Reports Server (NTRS)

    Kurland, Richard M.; Stella, Paul

    1989-01-01

    Phase 2 of the Advanced Photovoltaic Solar Array (APSA) program, started in mid-1987, is currently in progress to fabricate prototype wing hardware that will lead to wing integration and testing in 1989. The design configuration and key details are reviewed. A status of prototype hardware fabricated to date is provided. Results from key component-level tests are discussed. Revised estimates of array-level performance as a function of solar cell device technology for geosynchronous missions are given.

  2. Flexible concentrator photovoltaics based on microscale silicon solar cells embedded in luminescent waveguides

    SciTech Connect

    Yoon, Jongseung; Li, Lanfang; Semichaevsky, Andrey V.; Ryu, Jae Ha; Johnson, Harley T.; Nuzzo, Ralph G.; Rogers, John A.

    2011-06-14

    Unconventional methods to exploit monocrystalline silicon and other established materials in photovoltaic (PV) systems can create new engineering opportunities, device capabilities and cost structures. Here we show a type of composite luminescent concentrator PV system that embeds large scale, interconnected arrays of microscale silicon solar cells in thin matrix layers doped with luminophores. Photons that strike cells directly generate power in the usual manner; those incident on the matrix launch wavelength-downconverted photons that reflect and waveguide into the sides and bottom surfaces of the cells to increase further their power output, by more than 300% in examples reported here. Unlike conventional luminescent photovoltaics, this unusual design can be implemented in ultrathin, mechanically bendable formats. Detailed studies of design considerations and fabrication aspects for such devices, using both experimental and computational approaches, provide quantitative descriptions of the underlying materials science and optics.

  3. Flexible concentrator photovoltaics based on microscale silicon solar cells embedded in luminescent waveguides.

    PubMed

    Yoon, Jongseung; Li, Lanfang; Semichaevsky, Andrey V; Ryu, Jae Ha; Johnson, Harley T; Nuzzo, Ralph G; Rogers, John A

    2011-01-01

    Unconventional methods to exploit monocrystalline silicon and other established materials in photovoltaic (PV) systems can create new engineering opportunities, device capabilities and cost structures. Here we show a type of composite luminescent concentrator PV system that embeds large scale, interconnected arrays of microscale silicon solar cells in thin matrix layers doped with luminophores. Photons that strike cells directly generate power in the usual manner; those incident on the matrix launch wavelength-downconverted photons that reflect and waveguide into the sides and bottom surfaces of the cells to increase further their power output, by more than 300% in examples reported here. Unlike conventional luminescent photovoltaics, this unusual design can be implemented in ultrathin, mechanically bendable formats. Detailed studies of design considerations and fabrication aspects for such devices, using both experimental and computational approaches, provide quantitative descriptions of the underlying materials science and optics. PMID:21673664

  4. Titanium-containing zeolites and microporous molecular sieves as photovoltaic solar cells.

    PubMed

    Atienzar, Pedro; Valencia, Susana; Corma, Avelino; García, Hermenegildo

    2007-05-14

    Four titanium-containing zeolites and microporous molecular sieves differing on the crystal structure and particle size (Ti/Beta, Ti/Beta-60, TS-1 and ETS-10) are prepared, and their activity for solar cells after incorporating N3 (a commercially available ruthenium polypyridyl dye) is tested. All the zeolites exhibit photovoltaic activity, and the photoresponse is quite independent of the zeolite pore dimensions or particle size. The photoresponse increases with titanium content in the range 1-7% wt. In this way, cells are obtained that have open-circuit voltage Voc=560 mV and maximum short-circuit photocurrent density Isc=100 microA, measured for 1x1 cm2 surfaces with a solar simulator at 1000 W through and AM 1.5 filter. These values are promising and comparable to those obtained for current dye-sensitized titania solar cells. PMID:17410619

  5. Ecotoxicological assessment of solar cell leachates: Copper indium gallium selenide (CIGS) cells show higher activity than organic photovoltaic (OPV) cells.

    PubMed

    Brun, Nadja Rebecca; Wehrli, Bernhard; Fent, Karl

    2016-02-01

    Despite the increasing use of photovoltaics their potential environmental risks are poorly understood. Here, we compared ecotoxicological effects of two thin-film photovoltaics: established copper indium gallium selenide (CIGS) and organic photovoltaic (OPV) cells. Leachates were produced by exposing photovoltaics to UV light, physical damage, and exposure to environmentally relevant model waters, representing mesotrophic lake water, acidic rain, and seawater. CIGS cell leachates contained 583 μg L(-1) molybdenum at lake water, whereas at acidic rain and seawater conditions, iron, copper, zinc, molybdenum, cadmium, silver, and tin were present up to 7219 μg L(-1). From OPV, copper (14 μg L(-1)), zinc (87 μg L(-1)) and silver (78 μg L(-1)) leached. Zebrafish embryos were exposed until 120 h post-fertilization to these extracts. CIGS leachates produced under acidic rain, as well as CIGS and OPV leachates produced under seawater conditions resulted in a marked hatching delay and increase in heart edema. Depending on model water and solar cell, transcriptional alterations occurred in genes involved in oxidative stress (cat), hormonal activity (vtg1, ar), metallothionein (mt2), ER stress (bip, chop), and apoptosis (casp9). The effects were dependent on the concentrations of cationic metals in leachates. Addition of ethylenediaminetetraacetic acid protected zebrafish embryos from morphological and molecular effects. Our study suggests that metals leaching from damaged CIGS cells, may pose a potential environmental risk. PMID:26615488

  6. Decentalized solar photovoltaic energy systems

    SciTech Connect

    Krupka, M. C.

    1980-09-01

    Environmental data for decentralized solar photovoltaic systems have been generated in support of the Technology Assessment of Solar Energy Systems program (TASE). Emphasis has been placed upon the selection and use of a model residential photovoltaic system to develop and quantify the necessary data. The model consists of a reference home located in Phoenix, AZ, utilizing a unique solar cell array-roof shingle combination. Silicon solar cells, rated at 13.5% efficiency at 28/sup 0/C and 100 mW/cm/sup 2/ (AMI) insolation are used to generate approx. 10 kW (peak). An all-electric home is considered with lead-acid battery storage, dc-ac inversion and utility backup. The reference home is compared to others in regions of different insolation. Major material requirements, scaled to quad levels of end-use energy include significant quantities of silicon, copper, lead, antimony, sulfuric acid and plastics. Operating residuals generated are negligible with the exception of those from the storage battery due to a short (10-year) lifetime. A brief general discussion of other environmental, health, and safety and resource availability impacts is presented. It is suggested that solar cell materials production and fabrication may have the major environmental impact when comparing all facets of photovoltaic system usage. Fabrication of the various types of solar cell systems involves the need, handling, and transportation of many toxic and hazardous chemicals with attendant health and safety impacts. Increases in production of such materials as lead, antimony, sulfuric acid, copper, plastics, cadmium and gallium will be required should large scale usage of photovoltaic systems be implemented.

  7. Concentrating photovoltaic solar panel

    SciTech Connect

    Cashion, Steven A; Bowser, Michael R; Farrelly, Mark B; Hines, Braden E; Holmes, Howard C; Johnson, Jr., Richard L; Russell, Richard J; Turk, Michael F

    2014-04-15

    The present invention relates to photovoltaic power systems, photovoltaic concentrator modules, and related methods. In particular, the present invention features concentrator modules having interior points of attachment for an articulating mechanism and/or an articulating mechanism that has a unique arrangement of chassis members so as to isolate bending, etc. from being transferred among the chassis members. The present invention also features adjustable solar panel mounting features and/or mounting features with two or more degrees of freedom. The present invention also features a mechanical fastener for secondary optics in a concentrator module.

  8. Increased voltage photovoltaic cell

    NASA Technical Reports Server (NTRS)

    Ross, B.; Bickler, D. B.; Gallagher, B. D. (Inventor)

    1985-01-01

    A photovoltaic cell, such as a solar cell, is provided which has a higher output voltage than prior cells. The improved cell includes a substrate of doped silicon, a first layer of silicon disposed on the substrate and having opposite doping, and a second layer of silicon carbide disposed on the first layer. The silicon carbide preferably has the same type of doping as the first layer.

  9. Solar photovoltaic reflective trough collection structure

    SciTech Connect

    Anderson, Benjamin J.; Sweatt, William C.; Okandan, Murat; Nielson, Gregory N.

    2015-11-19

    A photovoltaic (PV) solar concentration structure having at least two troughs encapsulated in a rectangular parallelepiped optical plastic structure, with the troughs filled with an optical plastic material, the troughs each having a reflective internal surface and approximately parabolic geometry, and the troughs each including photovoltaic cells situated so that light impinging on the optical plastic material will be concentrated onto the photovoltaic cells. Multiple structures can be connected to provide a solar photovoltaic collection system that provides portable, efficient, low-cost electrical power.

  10. High temperature solid oxide regenerative fuel cell for solar photovoltaic energy storage

    NASA Technical Reports Server (NTRS)

    Bents, David J.

    1987-01-01

    A hydrogen-oxygen regenerative fuel cell energy storage system based on high temperature solid oxide fuel cell technology is discussed which has application to darkside energy storage for solar photovoltaics. The forward and reverse operating cycles are described, and heat flow, mass, and energy balance data are presented to characterize the system's performance and the variation of performance with changing reactant storage pressure. The present system weighs less than nickel hydrogen battery systems after 0.7 darkside operation, and it maintains a specific weight advantage over radioisotope generators for discharge periods up to 72 hours.

  11. Porous Silicon Modified Photovoltaic Junctions: An Approach to High-Efficiency Solar Cells

    NASA Astrophysics Data System (ADS)

    Badawy, Waheed A.

    2007-02-01

    The solution of the energy problems of our universe is based on the use of the ultimate source of energy, THE SUN, as the main source of useable energy. The trials to obtain solar cells of appropriate efficiency and suitable price represent one of the main tasks of different research groups over the whole world. In this respect silicon represent the main absorber of sun light that could be converted to electricity, photovoltaic cells, or to high energy chemical products, photoelectrochemical cells. Photovoltaic and photoelectrochemical systems were prepared by the formation of a thin porous film on silicon. The porous silicon layer was formed on the top of a clean oxide free silicon wafer surface by anodic etching in HF/H2O/C2H5OH mixture (2:1:1). The silicon was then covered by an oxide film (tin oxide, ITO or titanium oxide. The oxide films were prepared by the spray/pyrolysis technique which enables the incorporation of foreign atoms like In, Ru or Sb in the oxide film matrix during the spray process/. The incorporation of foreign atoms improves the surface characteristics of the oxide film which leads to the improvement of the fill factor and higher solar conversion efficiency. The prepared solar cells are stable against environmental attack due to the presence of the stable oxide film. It gives relatively high short circuit currents (Isc) compared to our improved silicon single crystal solar cells /6/, due to the presence of the porous silicon layer, which leads to the recorded high conversion efficiency. Although the open-circuit potential (Voc) and fill factor (FF) were not affected by the thickness of the porous silicon film, the short circuit current was found to be sensitive to this thickness. An optimum thickness of the porous film and also the oxide layer is required to optimize the solar cell efficiency. The results represent a promising system for the application of porous silicon layers in solar energy converters. The use of porous silicon instead of

  12. Enhanced photovoltaic performances of graphene/Si solar cells by insertion of a MoS2 thin film

    NASA Astrophysics Data System (ADS)

    Tsuboi, Yuka; Wang, Feijiu; Kozawa, Daichi; Funahashi, Kazuma; Mouri, Shinichiro; Miyauchi, Yuhei; Takenobu, Taishi; Matsuda, Kazunari

    2015-08-01

    Transition-metal dichalcogenides exhibit great potential as active materials in optoelectronic devices because of their characteristic band structure. Here, we demonstrated that the photovoltaic performances of graphene/Si Schottky junction solar cells were significantly improved by inserting a chemical vapor deposition (CVD)-grown, large MoS2 thin-film layer. This layer functions as an effective electron-blocking/hole-transporting layer. We also demonstrated that the photovoltaic properties are enhanced with the increasing number of graphene layers and the decreasing thickness of the MoS2 layer. A high photovoltaic conversion efficiency of 11.1% was achieved with the optimized trilayer-graphene/MoS2/n-Si solar cell.Transition-metal dichalcogenides exhibit great potential as active materials in optoelectronic devices because of their characteristic band structure. Here, we demonstrated that the photovoltaic performances of graphene/Si Schottky junction solar cells were significantly improved by inserting a chemical vapor deposition (CVD)-grown, large MoS2 thin-film layer. This layer functions as an effective electron-blocking/hole-transporting layer. We also demonstrated that the photovoltaic properties are enhanced with the increasing number of graphene layers and the decreasing thickness of the MoS2 layer. A high photovoltaic conversion efficiency of 11.1% was achieved with the optimized trilayer-graphene/MoS2/n-Si solar cell. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03046c

  13. High efficiency, broadband solar cell architectures based on arrays of volumetrically distributed narrowband photovoltaic fibers.

    PubMed

    O'Connor, Brendan; Nothern, Denis; Pipe, Kevin P; Shtein, Max

    2010-09-13

    We propose a novel solar cell architecture consisting of multiple fiber-based photovoltaic (PV) cells. Each PV fiber element is designed to maximize the power conversion efficiency within a narrow band of the incident solar spectrum, while reflecting other spectral components through the use of optical microcavity effects and distributed Bragg reflector (DBR) coatings. Combining PV fibers with complementary absorption and reflection characteristics into volume-filling arrays enables spectrally tuned modules having an effective dispersion element intrinsic to the architecture, resulting in high external quantum efficiency over the incident spectrum. While this new reflective tandem architecture is not limited to one particular material system, here we apply the concept to organic PV (OPV) cells that use a metal-organic-metal-dielectric layer structure, and calculate the expected performance of such arrays. Using realistic material properties for organic absorbers, transport layers, metallic electrodes, and DBR coatings, 17% power conversion efficiency can be reached. PMID:21165073

  14. Optimization of material/device parameters of CdTe photovoltaic for solar cells applications

    NASA Astrophysics Data System (ADS)

    Wijewarnasuriya, Priyalal S.

    2016-05-01

    Cadmium telluride (CdTe) has been recognized as a promising photovoltaic material for thin-film solar cell applications due to its near optimum bandgap of ~1.5 eV and high absorption coefficient. The energy gap is near optimum for a single-junction solar cell. The high absorption coefficient allows films as thin as 2.5 μm to absorb more than 98% of the above-bandgap radiation. Cells with efficiencies near 20% have been produced with poly-CdTe materials. This paper examines n/p heterostructure device architecture. The performance limitations related to doping concentrations, minority carrier lifetimes, absorber layer thickness, and surface recombination velocities at the back and front interfaces is assessed. Ultimately, the paper explores device architectures of poly- CdTe and crystalline CdTe to achieve performance comparable to gallium arsenide (GaAs).

  15. Enhancement in photovoltaic properties of silicon solar cells by surface plasmon effect of palladium nanoparticles

    NASA Astrophysics Data System (ADS)

    Atyaoui, Malek; Atyaoui, Atef; Khalifa, Marwen; Elyagoubi, Jalel; Dimassi, Wissem; Ezzaouia, Hatem

    2016-04-01

    This work presents the surface Plasmon effect of Palladium nanoparticles (Pd NPs) on the photovoltaic properties of silicon solar cells. Pd NPs were deposited on the p-type silicon base of the n+/p junction using a chemical deposition method in an aqueous solution containing Palladium (II) Nitrate (PdNO3)2 and Ammonium Hydroxide (NH4OH) followed by a thermal treatment at 500 °C under nitrogen atmosphere. Chemical composition and surface morphology of the treated silicon base were examined by energy dispersive X-ray (EDX) spectroscopy, scanning electronic microscopy (SEM) and Atomic Force Microscopy (AFM). The effect of the deposited Pd NPs on the electrical properties was evaluated by the internal quantum efficiency (IQE) and current-voltage (I-V) measurements. The results indicate that the formation of the Pd NPs is accompanied by an enhanced light absorption and improved photovoltaic parameters.

  16. Electricity from photovoltaic solar cells. Flat-Plate Solar Array Project of the US Department of Energy's National Photovoltaics Program: 10 years of progress

    NASA Technical Reports Server (NTRS)

    Christensen, Elmer

    1985-01-01

    The objectives were to develop the flat-plate photovoltaic (PV) array technologies required for large-scale terrestrial use late in the 1980s and in the 1990s; advance crystalline silicon PV technologies; develop the technologies required to convert thin-film PV research results into viable module and array technology; and to stimulate transfer of knowledge of advanced PV materials, solar cells, modules, and arrays to the PV community. Progress reached on attaining these goals, along with future recommendations are discussed.

  17. Solar radiation on Mars: Stationary photovoltaic array

    NASA Technical Reports Server (NTRS)

    Appelbaum, J.; Sherman, I.; Landis, G. A.

    1993-01-01

    Solar energy is likely to be an important power source for surface-based operation on Mars. Photovoltaic cells offer many advantages. In this article we have presented analytical expressions and solar radiation data for stationary flat surfaces (horizontal and inclined) as a function of latitude, season and atmospheric dust load (optical depth). The diffuse component of the solar radiation on Mars can be significant, thus greatly affecting the optimal inclination angle of the photovoltaic surface.

  18. Space Solar Cell Research and Development Projects at Emcore Photovoltaics

    NASA Technical Reports Server (NTRS)

    Sharps, Paul; Aiken,Dan; Stan, Mark; Cornfeld, Art; Newman, Fred; Endicter, Scott; Girard, Gerald; Doman, John; Turner, Michele; Sandoval, Annette; Fatemi, Navid

    2007-01-01

    The GaInP2/InGaAs/Ge triple junction device lattice matched to germanium has achieved the highest power conversion efficiency and the most commercial success for space applications [1]. What are the practical performance limits of this technology? In this paper we will describe what we consider to be the practical performance limits of the lattice matched GaInP2/InGaAs/Ge triple junction cell. In addition, we discuss the options for next generation space cell performance.

  19. Advances in thin-film solar cells for lightweight space photovoltaic power

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Bailey, Sheila G.; Flood, Dennis J.

    1989-01-01

    The development of photovoltaic arrays beyond the next generation is discussed with attention given to the potentials of thin-film polycrystalline and amorphous cells. Of particular importance is the efficiency (the fraction of incident solar energy converted to electricity) and specific power (power to weight ratio). It is found that the radiation tolerance of thin-film materials is far greater than that of single crystal materials. CuInSe2 shows no degradation when exposed to 1-MeV electrons.

  20. Intermediate-band dynamics of quantum dots solar cell in concentrator photovoltaic modules

    PubMed Central

    Sogabe, Tomah; Shoji, Yasushi; Ohba, Mitsuyoshi; Yoshida, Katsuhisa; Tamaki, Ryo; Hong, Hwen-Fen; Wu, Chih-Hung; Kuo, Cherng-Tsong; Tomić, Stanko; Okada, Yoshitaka

    2014-01-01

    We report for the first time a successful fabrication and operation of an InAs/GaAs quantum dot based intermediate band solar cell concentrator photovoltaic (QD-IBSC-CPV) module to the IEC62108 standard with recorded power conversion efficiency of 15.3%. Combining the measured experimental results at Underwriters Laboratory (UL®) licensed testing laboratory with theoretical simulations, we confirmed that the operational characteristics of the QD-IBSC-CPV module are a consequence of the carrier dynamics via the intermediate-band at room temperature. PMID:24762433

  1. Advances in thin-film solar cells for lightweight space photovoltaic power

    SciTech Connect

    Landis, G.A.; Bailey, S.G.; Flood, D.J.

    1989-01-01

    The present stature and current research directions of photovoltaic arrays as primary power systems for space are reviewed. There have recently been great advances in the technology of thin-film solar cells for terrestrial applications. In a thin-film solar cell the thickness of the active element is only a few microns; transfer of this technology to space arrays could result in ultralow-weight solar arrays with potentially large gains in specific power. Recent advances in thin-film solar cells are reviewed, including polycrystalline copper-indium selenide (CuInSe2) and related I-III-VI2 compounds, polycrystalline cadmium telluride and related II-VI compounds, and amorphous silicon:hydrogen and alloys. The best experimental efficiency on thin-film solar cells to date is 12 percent AMO for CuInSe2. This efficiency is likely to be increased in the next few years. The radiation tolerance of thin-film materials is far greater than that of single-crystal materials. CuInSe2 shows no degradation when exposed to 1 MeV electrons. Experimental evidence also suggests that most of all of the radiation damage on thin-films can be removed by a low temperature anneal. The possibility of thin-film multibandgap cascade solar cells is discussed, including the tradeoffs between monolithic and mechanically stacked cells. The best current efficiency for a cascade is 12.5 percent AMO for an amorphous silicon on CuInSe2 multibandgap combination. Higher efficiencies are expected in the future. For several missions, including solar-electric propulsion, a manned Mars mission, and lunar exploration and manufacturing, thin-film photovolatic arrays may be a mission-enabling technology.

  2. Advances in thin-film solar cells for lightweight space photovoltaic power

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Bailey, Sheila G.; Flood, Dennis J.

    1989-01-01

    The present stature and current research directions of photovoltaic arrays as primary power systems for space are reviewed. There have recently been great advances in the technology of thin-film solar cells for terrestrial applications. In a thin-film solar cell the thickness of the active element is only a few microns; transfer of this technology to space arrays could result in ultralow-weight solar arrays with potentially large gains in specific power. Recent advances in thin-film solar cells are reviewed, including polycrystalline copper-indium selenide (CuInSe2) and related I-III-VI2 compounds, polycrystalline cadmium telluride and related II-VI compounds, and amorphous silicon:hydrogen and alloys. The best experimental efficiency on thin-film solar cells to date is 12 percent AMO for CuIn Se2. This efficiency is likely to be increased in the next few years. The radiation tolerance of thin-film materials is far greater than that of single-crystal materials. CuIn Se2 shows no degradation when exposed to 1 MeV electrons. Experimental evidence also suggests that most of all of the radiation damage on thin-films can be removed by a low temperature anneal. The possibility of thin-film multibandgap cascade solar cells is discussed, including the tradeoffs between monolithic and mechanically stacked cells. The best current efficiency for a cascade is 12.5 percent AMO for an amorphous silicon on CuInSe2 multibandgap combination. Higher efficiencies are expected in the future. For several missions, including solar-electric propulsion, a manned Mars mission, and lunar exploration and manufacturing, thin-film photovolatic arrays may be a mission-enabling technology.

  3. Smart photovoltaics based on dye-sensitized solar cells using photochromic spiropyran derivatives as photosensitizers

    NASA Astrophysics Data System (ADS)

    Ma, Shengbo; Ting, Hungkit; Ma, Yingzhuang; Zheng, Lingling; Zhang, Miwei; Xiao, Lixin; Chen, Zhijian

    2015-05-01

    In this paper, smart photovoltaic (SPV) devices, integrating both functions of solar cells and smart windows, was fabricated based on dye-sensitized solar cells using photochromic spiropyran derivatives SIBT as photosensitizers. SPV devices have self-regulated power conversion efficiency (PCE) and light transmission responding to the incident spectra due to the photoisomerization of SIBT. SIBT isomerize from closed-ring form to open-ring form under UV illumination, accompanied with enhanced visible light absorption and electron delocalization. Therefore, increased PCE and absorption in SPV devices were observed under UV treatment and the devices can be restored gradually to the initial status when kept in dark. The SPV devices have self-regulation of PCE and sunlight transmission responding to the changing sun spectra in different times of a day, providing a proper energy usage and a better sun-shading.

  4. Fabrication and photovoltaic properties of ZnO nanorods/perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Shirahata, Yasuhiro; Tanaike, Kohei; Akiyama, Tsuyoshi; Fujimoto, Kazuya; Suzuki, Atsushi; Balachandran, Jeyadevan; Oku, Takeo

    2016-02-01

    ZnO nanorods/perovskite solar cells with different lengths of ZnO nanorods were fabricated. The ZnO nanorods were prepared by chemical bath deposition and directly confirmed to be hexagon-shaped nanorods. The lengths of the ZnO nanorads were controlled by deposition condition of ZnO seed layer. Photovoltaic properties of the ZnO nanorods/CH3NH3PbI3 solar cells were investigated by measuring current density-voltage characteristics and incident photon to current conversion efficiency. The highest conversion efficiency was obtained in ZnO nanorods/CH3NH3PbI3 with the longest ZnO nanorods.

  5. Al-doping effects on the photovoltaic performance of inverted polymer solar cells

    NASA Astrophysics Data System (ADS)

    Yu, Xuan; Shi, Ya-feng; Yu, Xiao-ming; Zhang, Jian-jun; Ge, Ya-ming; Chen, Li-qiao; Pan, Hong-jun

    2016-03-01

    The properties of Al-doped ZnO (AZO) play an important role in the photovoltaic performance of inverted polymer solar cells (PSCs), which is used as electron transport and hole blocking buffer layers. In this work, we study the effects of Al-doping level in AZO on device performance in detail. Results indicate that the device performance intensely depends on the Al-doping level. The AZO thin films with Al-doping atomic percentage of 1.0% possess the best conductivity. The resulting solar cells show the enhanced short current density and the fill factor ( FF) simultaneously, and the power conversion efficiency ( PCE) is improved by 74%, which are attributed to the reduced carrier recombination and the optimized charge transport and extraction between AZO and the active layer.

  6. Smart photovoltaics based on dye-sensitized solar cells using photochromic spiropyran derivatives as photosensitizers

    SciTech Connect

    Ma, Shengbo; Ting, Hungkit; Ma, Yingzhuang; Zheng, Lingling; Zhang, Miwei; Xiao, Lixin E-mail: lxxiao@pku.edu.cn; Chen, Zhijian E-mail: lxxiao@pku.edu.cn

    2015-05-15

    In this paper, smart photovoltaic (SPV) devices, integrating both functions of solar cells and smart windows, was fabricated based on dye-sensitized solar cells using photochromic spiropyran derivatives SIBT as photosensitizers. SPV devices have self-regulated power conversion efficiency (PCE) and light transmission responding to the incident spectra due to the photoisomerization of SIBT. SIBT isomerize from closed-ring form to open-ring form under UV illumination, accompanied with enhanced visible light absorption and electron delocalization. Therefore, increased PCE and absorption in SPV devices were observed under UV treatment and the devices can be restored gradually to the initial status when kept in dark. The SPV devices have self-regulation of PCE and sunlight transmission responding to the changing sun spectra in different times of a day, providing a proper energy usage and a better sun-shading.

  7. Photovoltaic cell

    SciTech Connect

    Jordan, J.F.; Lampkin, C.M.

    1981-12-08

    A photovoltaic cell has: an electrically conductive substrate, which may be glass having a film of conductive tin oxide; a first layer containing a suitable semiconductor, which layer has a first component film with an amorphous structure and a second component film with a polycrystalline structure; a second layer forming a heterojunction with the first layer; and suitable electrodes where the heterojunction is formed from a solution containing copper, the amorphous film component is superposed above an electrically conductive substrate to resist permeation of the copper-containing material to shorting electrical contact with the substrate. The penetration resistant amporphous layer permits a variety of processes to be used in forming the heterojunction with even very thin layers (1-6 mu thick) of underlying polycrystalline semi-conductor materials. In some embodiments, the amorphous-like structure may be formed by the addition of aluminum or zirconium compounds to a solution of cadmium salts sprayed over a heated substrate.

  8. The lateral photovoltaic effect in CdS-Cu2S heterojunction solar cell

    NASA Astrophysics Data System (ADS)

    Islam, M. N.; Haque, M. A.

    1982-06-01

    The lateral photovoltaic effect has been observed in CdS-Cu2S thin-film solar cells. The effect is more pronounced on the CdS side than on the Cu2S side of the cells. On the CdS side, where the contacts were formed by soldering Cu wire by indium and then applying Ag paint, the photovoltage developed were found to increase as the point of illumination was moved towards the contact. The spectral response of photovoltage for coevaporated cells shows a peak at λ=0.5μm (2.45 eV). But for topotaxial cells two peaks, one at λ=0.5μm and the other at λ=0.65μm (1.89eV) were observed. A band model has been proposed for the heat-treated optimized cells.

  9. The lateral photovoltaic effect in CdS-Cu2S heterojunction solar cell

    NASA Astrophysics Data System (ADS)

    Islam, M. N.; Haque, M. A.

    1982-06-01

    The lateral photovoltaic effect has been observed in CdS-Cu2S thin-film solar cells. The effect is more pronounced on the CdS side than on the Cu2S side of the cells. On the CdS side, where the contacts were formed by soldering Cu wire by indium and then applying Ag paint, the photovoltage developed were found to increase as the point of illumination was moved towards the contact. The spectral response of photovoltage for coevaporated cells shows a peak at 0.5 micron (2.45 eV). But for topotaxial cells two peaks, one at 0.5 micron and the other at 0.65 micron (1.89 eV) were observed. A band model has been proposed for the heat-treated optimized cells.

  10. Advanced Rainbow Solar Photovoltaic Arrays

    NASA Technical Reports Server (NTRS)

    Mardesich, Nick; Shields, Virgil

    2003-01-01

    Photovoltaic arrays of the rainbow type, equipped with light-concentrator and spectral-beam-splitter optics, have been investigated in a continuing effort to develop lightweight, high-efficiency solar electric power sources. This investigation has contributed to a revival of the concept of the rainbow photovoltaic array, which originated in the 1950s but proved unrealistic at that time because the selection of solar photovoltaic cells was too limited. Advances in the art of photovoltaic cells since that time have rendered the concept more realistic, thereby prompting the present development effort. A rainbow photovoltaic array comprises side-by-side strings of series-connected photovoltaic cells. The cells in each string have the same bandgap, which differs from the bandgaps of the other strings. Hence, each string operates most efficiently in a unique wavelength band determined by its bandgap. To obtain maximum energy-conversion efficiency and to minimize the size and weight of the array for a given sunlight input aperture, the sunlight incident on the aperture is concentrated, then spectrally dispersed onto the photovoltaic array plane, whereon each string of cells is positioned to intercept the light in its wavelength band of most efficient operation. The number of cells in each string is chosen so that the output potentials of all the strings are the same; this makes it possible to connect the strings together in parallel to maximize the output current of the array. According to the original rainbow photovoltaic concept, the concentrated sunlight was to be split into multiple beams by use of an array of dichroic filters designed so that each beam would contain light in one of the desired wavelength bands. The concept has since been modified to provide for dispersion of the spectrum by use of adjacent prisms. A proposal for an advanced version calls for a unitary concentrator/ spectral-beam-splitter optic in the form of a parabolic curved Fresnel-like prism

  11. Effect of annealing on photovoltaic performance of fabricated planar organic-inorganic perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Baltakesmez, Ali; Biber, Mehmet; Tüzemen, Sebahattin

    2016-04-01

    We fabricated planar perovskite solar cells used CH3NH3PbI3-xClx for light harvesting to investigate effect of annealing on photovoltaic performance of fabricated device. The devices have an architecture of Glass/ITO/Pedot:PSS/Perovskite/PC61BM/Al. Layers of hole transport (Pedot:PSS), active and electron transport (PC61BM) were prepared from solution based one step deposition method by a spin coater and standard annealing procedure. The current‑voltage curves of devices were measured inside the glovebox using a Keithley 2400 sourcemeter. The cells were illuminated by a solar simulator have optical intensity value of 300 mW/cm2. For the best cells, while PCE value of 5.78% before the annealing, photovoltaic efficiency was improved average 13% delivered a short-circuit current density of 3.20 mA/cm2, open-circuit voltage of 0.82 V and fill factor of 0.74, leading to an efficiency of 6.54% with respect to prior to annealing.

  12. Approaches to Future Generation Photovoltaics and Solar Fuels: Quantum Dots, Arrays, and Quantum Dot Solar Cells

    SciTech Connect

    Semonin, O.; Luther, J.; Beard, M.; Johnson, J.; Gao, J.; Nozik, A.

    2012-01-01

    One potential, long-term approach to more efficient and lower cost future generation solar cells for solar electricity and solar fuels is to utilize the unique properties of quantum dots (QDs) to control the relaxation pathways of excited states to enhance multiple exciton generation (MEG). We have studied MEG in close-packed PbSe QD arrays where the QDs are electronically coupled in the films and thus exhibit good transport while still maintaining quantization and MEG. We have developed simple, all-inorganic solution-processable QD solar cells that produce large short-circuit photocurrents and power conversion efficiencies above 5% via nanocrystalline p-n junctions. These solar cells show QYs for photocurrent that exceed 100% in the photon energy regions where MEG is possible; the photocurrent MEG QYs as a function of photon energy match those determined via time-resolved spectroscopy Recent analyses of the major effect of MEG combined with solar concentration on the conversion efficiency of solar cells will also be discussed.

  13. Photovoltaic properties and morphology of organic solar cells based on liquid-crystal semiconducting polymer with additive

    SciTech Connect

    Suzuki, Atsushi; Zushi, Masahito; Suzuki, Hisato; Ogahara, Shinichi; Akiyama, Tsuyoshi; Oku, Takeo

    2014-02-20

    Bulk heterojunction organic solar cell based on liquid crystal semiconducting polymers of poly[9,9-dioctylfluorene-co-bithiophene] (F8T2) as p-type semiconductors and fullerenes (C{sub 60}) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) as electron donor and acceptor has been fabricated and characterized for improving photovoltaic and optical properties. The photovoltaic performance including current voltage curves in the dark and illumination of the F8T2/C{sub 60} conventional and inverted bulk heterojunction solar cells were investigated. Relationship between the photovoltaic properties and morphological behavior was focused on tuning for optimization of photo-voltaic performance under annealing condition near glass transition temperature. Additive-effect of diiodooctane (DIO) and poly(3-hexylthiophene-2,5-diyl) (P3HT) on the photovoltaic performance and optical properties was investigated. Mechanism of the photovoltaic properties of the conventional and inverted solar cells will be discussed by the experimental results.

  14. InGaN-based thin film solar cells: Epitaxy, structural design, and photovoltaic properties

    SciTech Connect

    Sang, Liwen; Liao, Meiyong; Koide, Yasuo; Sumiya, Masatomo

    2015-03-14

    In{sub x}Ga{sub 1−x}N, with the tunable direct bandgaps from ultraviolet to near infrared region, offers a promising candidate for the high-efficiency next-generation thin-film photovoltaic applications. Although the adoption of thick InGaN film as the active region is desirable to obtain efficient light absorption and carrier collection compared to InGaN/GaN quantum wells structure, the understanding on the effect from structural design is still unclear due to the poor-quality InGaN films with thickness and difficulty of p-type doping. In this paper, we comprehensively investigate the effects from film epitaxy, doping, and device structural design on the performances of the InGaN-based solar cells. The high-quality InGaN thick film is obtained on AlN/sapphire template, and p-In{sub 0.08}Ga{sub 0.92}N is achieved with a high hole concentration of more than 10{sup 18 }cm{sup −3}. The dependence of the photovoltaic performances on different structures, such as active regions and p-type regions is analyzed with respect to the carrier transport mechanism in the dark and under illumination. The strategy of improving the p-i interface by using a super-thin AlN interlayer is provided, which successfully enhances the performance of the solar cells.

  15. The Influence of Substituent Orientation on the Photovoltaic Performance of Phthalocyanine-Sensitized Solar Cells.

    PubMed

    Tejerina, Lara; Martínez-Díaz, M Victoria; Nazeeruddin, Mohammad Khaja; Torres, Tomas

    2016-03-18

    Phthalocyanines (Pcs) are used as sensitizers in dye-sensitized solar cells (DSSCs) because of their stability and intense absorption in the red and near-IR regions. Impressive progress has been made in photovoltaic efficiencies by introduction of bulky peripheral substituents to help suppress macrocycle aggregation. To reach benchmark efficiencies reported for other related dyes, new designs need to be explored. Single carboxy-ZnPc regioisomers substituted at the non-peripheral positions by rigid aryl groups have now been studied, which has shed light on the influence of steric hindrance and/or orientation of the substituent around the anchoring group on the photovoltaic response. The regioisomer bearing the aryl group far away from the anchoring group produces a more effective sensitization of the TiO2 films and higher short-circuit photocurrent density (Jsc). Taking advantage of the good photovoltaic performance in the near-IR region of this ZnPc, it was combined with another appropriate dye for panchromatic sensitization of the mesoporous photoelectrode and an increase of the overall device efficiency. PMID:26777385

  16. Inexpensive Photovoltaic Solar Radiometer.

    ERIC Educational Resources Information Center

    Kissner, Fritz

    1981-01-01

    Describes a low-cost instrument using a solar cell as a sensor to measure both instantaneous and integrated value of solar flux. Constructing and calibrating such an instrument constitutes an undergraduate experimental project, affording students an opportunity to examine a variety of aspects associated with solar energy measurements. (Author/SK)

  17. Aluminium alloyed iron-silicide/silicon solar cells: A simple approach for low cost environmental-friendly photovoltaic technology

    NASA Astrophysics Data System (ADS)

    Kumar Dalapati, Goutam; Masudy-Panah, Saeid; Kumar, Avishek; Cheh Tan, Cheng; Ru Tan, Hui; Chi, Dongzhi

    2015-12-01

    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/cm2, 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.

  18. Nanopillar Photovoltaics: Photon Management and Junction Engineering for Next-Generation Solar Cells

    NASA Astrophysics Data System (ADS)

    Mariani, Giacomo

    The sun delivers an amount of energy equivalent to ninety billion hydrogen bombs detonating each second. Despite the fact that only one billionth of that energy falls onto the surface of the Earth, one day of sunlight would be sufficient to power the whole human race energy needs for over half a century. Solar electricity represents an environmentally-benign source of power. However, such technology is still more than twice as expensive as natural gas-fired generators. III-V semiconductor nanopillars are defined as vertically aligned arrays of nanostructures that hold the promise to aggressively diminish the cost of the active photovoltaic cell by exploiting a fraction of material utilized in conventional planar schemes. In this dissertation, we assess the viability of two classes of high-performance nanopillar-based solar cells. We begin with the incorporation of dedicated conjugated polymers to achieve a hybrid organic/inorganic heterojunction. Such configuration introduces a high optical absorption arising from the polymeric layer in conjunction with an efficient carrier transport resulting from the semiconductor nanopillar array. We extend the controllability of the heterojunction properties by replacing traditional spin-casting methods with an electrodeposition technique where the polymer is formed and doped in-situ directly onto the nanopillar facets. The rational tuning of the electrical conductivity and energy level of the polymer translates into an enhanced photocurrent and open-circuit voltage, achieving 4.11% solar power conversion efficiency. We then turn our attention to all-semiconductor radial p-n homojunctions embedded in the nanopillars. The first architecture focuses on ex-situ ammonium-sulfide passivation and correlates the optoelectronic properties of the solar cell once two different types of transparent conducting oxides are adopted. The barrier formed at the contact/semiconductor interface greatly depends on the Hall polarity of the

  19. Photovoltaic characteristics of n(+)pp(+) InP solar cells grown by OMVPE

    NASA Technical Reports Server (NTRS)

    Tyagi, S.; Singh, K.; Bhimnathwala, H.; Ghandhi, S. K.; Borrego, J. M.

    1990-01-01

    The photovoltaic characteristics of n(+)/p/p(+) homojunction InP solar cells fabricated by organometallic vapor-phase epitaxy (OMVPE) are described. The cells are characterized by I-V, C-V and quantum efficiency measurements, and simulations are used to obtain various device and material parameters. The I-V characteristics show a high recombination rate in the depletion region; this is shown to be independent of the impurity used. It is shown that cadmium is easier to use as an acceptor for the p base and p(+) buffer and is therefore beneficial. The high quantum efficiency of 98 percent at long wavelengths measured in these cells indicates a very good collection efficiency in the base. The short-wavelength quantum efficiency is poor, indicating a high surface recombination.

  20. Photovoltaic cell

    SciTech Connect

    Jordan, J. F.; Lampkin, C. M.

    1981-02-03

    A photovoltaic cell is disclosed having an electrically conductive substrate, which may be glass having a film of conductive tin oxide. A first layer contains a suitable semiconductor, which layer has a first component film with an amorphous structure and a second component film with a polycrystalline structure a second layer forms a heterojunction with the first layer suitable electrodes are provided where the heterojunction is formed from a solution containing copper, and the amorphous film component is superposed above an electrically conductive substrate to resist permeation of the copper-containing material to shorting electrical contact with the substrate. The penetration resistant amorphous layer permits a variety of processes to be used in forming the heterojunction with even very thin layers (1-6 mu thick) of underlying polycrystalline semi-conductor materials. In some embodiments, the amorphous-like structure may be formed by the addition of aluminum or zirconium compounds to a solution of cadmium salts sprayed over a heated substrate.

  1. Point-focus spectral splitting solar concentrator for multiple cells concentrating photovoltaic system

    NASA Astrophysics Data System (ADS)

    Maragliano, Carlo; Chiesa, Matteo; Stefancich, Marco

    2015-10-01

    In this paper we present and experimentally validate a low-cost design of a spectral splitting concentrator for the efficient conversion of solar energy. The optical device consists of a dispersive prismatic lens made of polycarbonate designed to simultaneously concentrate solar light and split it into its spectral components. With respect to our previous implementation, this device concentrates light along two axes and generates a light pattern compatible with the dimensions of a set of concentrating photovoltaic cells, while providing a higher concentration ratio. The mathematical framework and the constructive approach used for the design are presented and the device performance is simulated using ray-tracing software. We obtain spectral separation in the visible range within a 3 × 1 cm2 area and a maximum concentration of 210× for a single wavelength. The device is fabricated by injection molding and its performance is experimentally investigated. We measure an optical transmissivity above 90% in the range 400-800 nm and we observe a spectral distribution in good accordance with simulations. Our results demonstrate the feasibility of the device for cost effective high efficiency concentrated photovoltaic systems.

  2. Catalyzing Mass Production of Solar Photovoltaic Cells Using University Driven Green Purchasing

    ERIC Educational Resources Information Center

    Pearce, Joshua M.

    2006-01-01

    Purpose: The purpose of this paper is to explore the use of the purchase power of the higher education system to catalyze the economy of scale necessary to ensure market competitiveness for solar photovoltaic electricity. Design/methodology/approach: The approach used here was to first determine the demand necessary to construct "Solar City…

  3. Impacts of Post-metallisation Processes on the Electrical and Photovoltaic Properties of Si Quantum Dot Solar Cells

    PubMed Central

    2010-01-01

    As an important step towards the realisation of silicon-based tandem solar cells using silicon quantum dots embedded in a silicon dioxide (SiO2) matrix, single-junction silicon quantum dot (Si QD) solar cells on quartz substrates have been fabricated. The total thickness of the solar cell material is 420 nm. The cells contain 4 nm diameter Si quantum dots. The impacts of post-metallisation treatments such as phosphoric acid (H3PO4) etching, nitrogen (N2) gas anneal and forming gas (Ar: H2) anneal on the cells’ electrical and photovoltaic properties are investigated. The Si QD solar cells studied in this work have achieved an open circuit voltage of 410 mV after various processes. Parameters extracted from dark I–V, light I–V and circular transfer length measurement (CTLM) suggest limiting mechanism in the Si QD solar cell operation and possible approaches for further improvement. PMID:21124642

  4. Analyzing luminescent solar concentrators with front-facing photovoltaic cells using weighted Monte Carlo ray tracing

    NASA Astrophysics Data System (ADS)

    Woei Leow, Shin; Corrado, Carley; Osborn, Melissa; Isaacson, Michael; Alers, Glenn; Carter, Sue A.

    2013-06-01

    Luminescent solar concentrators (LSC) collect ambient light from a broad range of angles and concentrate the captured light onto photovoltaic (PV) cells. LSCs with front-facing cells collect direct and indirect sunlight ensuring a gain factor greater than one. The flexible placement and percentage coverage of PV cells on the LSC panel allow for layout adjustments to be made in order to balance re-absorption losses and the level of light concentration desired. A weighted Monte Carlo ray tracing program was developed to study the transport of photons and loss mechanisms in the LSC to aid in design optimization. The program imports measured absorption/emission spectra of an organic luminescent dye (LR305), the transmission coefficient, and refractive index of acrylic as parameters that describe the system. Simulations suggest that for LR305, 8-10 cm of luminescent material surrounding the PV cell yields the highest increase in power gain per unit area of LSC added, thereby determining the ideal spacing between PV cells in the panel. For rectangular PV cells, results indicate that for each centimeter of PV cell width, an additional increase of 0.15 mm to the waveguide thickness is required to efficiently transport photon collected by the LSC to the PV cell with minimal loss.

  5. Tandem photovoltaic solar cell with III-V diffused junction booster cell

    SciTech Connect

    Fraas, L.M.; Avery, J.E.; Girard, G.R.

    1992-02-25

    This patent describes a GaAs/GaSb tandem solar cell having improved conversion efficiency. It comprises: a GaAs upper cell having a predetermined bandgap selected for optimal performance of the tandem solar cell; a GaSb booster cell positioned beneath the GaAs upper cell to receive light transmitted through the GaAs upper cell and responsive to such light; and light conditioning means associated with the upper cell and the booster cell for achieving and energy conversion efficiency of at least 31% AMO. This patent also describes the cell as defined in claim 2, wherein the light conditioning means includes a prismatic coverglass for optically eliminating grid line obscuration losses on at least the upper cell and a concentrating lens for focusing solar energy onto an upper surface of the upper cell.

  6. Effect of electrode geometry on photovoltaic performance of polymer solar cells

    NASA Astrophysics Data System (ADS)

    Li, Meng; Ma, Heng; Liu, Hairui; Wu, Dongge; Niu, Heying; Cai, Wenjun

    2014-10-01

    This paper investigates the impact of electrode geometry on the performance of polymer solar cells (PSCs). The negative electrodes with equal area (0.09 cm2) but different shape (round, oval, square and triangular) are evaluated with respect to short-circuit current density, open-circuit voltage, fill factor and power conversion efficiency of PSCs. The results show that the device with round electrodes gives the best photovoltaic performance; in contrast, the device with triangular electrodes reveals the worst properties. A maximum of almost a 19% increase in power conversion efficiency with a round electrode is obtained in the devices compared with that of the triangular electrode. To conclude, the electrode boundary curvature has a significant impact on the performance of PSCs. The larger curvature, i.e. sharper electrodes edges, perhaps has a negative effect on exciton separation and carrier transport in photoelectric conversion processes.

  7. Effects of Immersion Solvent on Photovoltaic and Photophysical Properties of Porphyrin-Sensitized Solar Cells.

    PubMed

    Hayashi, Hironobu; Higashino, Tomohiro; Kinjo, Yuriko; Fujimori, Yamato; Kurotobi, Kei; Chabera, Pavel; Sundström, Villy; Isoda, Seiji; Imahori, Hiroshi

    2015-08-26

    Memory effects in self-assembled monolayers (SAMs) of zinc porphyrin carboxylic acid on TiO2 electrodes have been demonstrated for the first time by evaluating the photovoltaic and electron transfer properties of porphyrin-sensitized solar cells prepared by using different immersion solvents sequentially. The structure of the SAM of the porphyrin on the TiO2 was maintained even after treating the porphyrin monolayer with different neat immersion solvents (memory effect), whereas it was altered by treatment with solutions containing different porphyrins (inverse memory effect). Infrared spectroscopy shows that the porphyrins in the SAM on the TiO2 could be exchanged with the same or analogous porphyrin, leading to a change in the structure of the porphyrin SAM. The memory and inverse memory effects are well correlated with a change in porphyrin geometry, mainly the tilt angle of the porphyrin along the long molecular axis from the surface normal on the TiO2, as well as with kinetics of electron transfer between the porphyrin and TiO2. Such a new structure-function relationship for DSSCs will be very useful for the rational design and optimization of photoelectrochemical and photovoltaic properties of molecular assemblies on semiconductor surfaces. PMID:26266818

  8. Positive temperature coefficient of photovoltaic efficiency in solar cells based on InGaN/GaN MQWs

    NASA Astrophysics Data System (ADS)

    Chen, Zhaoying; Zheng, Xiantong; Li, Zhilong; Wang, Ping; Rong, Xin; Wang, Tao; Yang, Xuelin; Xu, Fujun; Qin, Zhixin; Ge, Weikun; Shen, Bo; Wang, Xinqiang

    2016-08-01

    We report a 23.4% improvement of conversion efficiency in solar cells based on InGaN/GaN multiple quantum wells by using a patterned sapphire substrate in the fabrication process. The efficiency enhancement is due to the improvement of the crystalline quality, as proven by the reduction of the threading dislocation density. More importantly, the better crystalline quality leads to a positive photovoltaic efficiency temperature coefficient up to 423 K, which shows the property and advantage of wide gap semiconductors like InGaN, signifying the potential of III-nitride based solar cells for high temperature and concentrating solar power applications.

  9. Measuring complex for studying cascade solar photovoltaic cells and concentrator modules on their basis

    NASA Astrophysics Data System (ADS)

    Larionov, V. R.; Malevskii, D. A.; Pokrovskii, P. V.; Rumyantsev, V. D.

    2015-06-01

    The design and implementation of several measuring complexes intended for studying cascade solar photovoltaic converters are considered. The complexes consist of a solar simulator and an electronic unit with an active load. The high-aperture light source of the complex reproduces solar intensity over wide spectral range λ = 350-1700 nm with an angle of divergence of ±0.26°, which are characteristic of solar radiation. The active load of the electronic unit allows taking both dark and illuminated I- V characteristics of test objects within about 1 ms during the quasi-stationary part of the irradiation pulse. The small size and low power consumption of the complexes hold out the hope that they will be widely used in designing, refining, and testing cascade efficient photovoltaic converters made of III-V materials and solar modules integrating these converters with concentrator modules.

  10. InGaP-based quantum well solar cells: Growth, structural design, and photovoltaic properties

    NASA Astrophysics Data System (ADS)

    Hashem, Islam E.; Zachary Carlin, C.; Hagar, Brandon G.; Colter, Peter C.; Bedair, S. M.

    2016-03-01

    Raising the efficiency ceiling of multi-junction solar cells (MJSCs) through the use of more optimal band gap configurations of next-generation MJSC is crucial for concentrator and space systems. Towards this goal, we propose two strain balanced multiple quantum well (SBMQW) structures to tune the bandgap of InGaP-based solar cells. These structures are based on InxGa1-xAs1-zPz/InyGa1-yP (x > y) and InxGa1-xP/InyGa1-yP (x > y) well/barrier combinations, lattice matched to GaAs in a p-i-n solar cell device. The bandgap of InxGa1-xAs1-zPz/InyGa1-yP can be tuned from 1.82 to 1.65 eV by adjusting the well composition and thickness, which promotes its use as an efficient subcell for next generation five and six junction photovoltaic devices. The thicknesses of wells and barriers are adjusted using a zero net stress balance model to prevent the formation of defects. Thin layers of InGaAsP wells have been grown thermodynamically stable with compositions within the miscibility gap for the bulk alloy. The growth conditions of the two SBMQWs and the individual layers are reported. The structures are characterized and analyzed by optical microscopy, X-ray diffraction, photoluminescence, current-voltage characteristics, and spectral response (external quantum efficiency). The effect of the well number on the excitonic absorption of InGaAsP/InGaP SBMQWs is discussed and analyzed.

  11. Transparent ultraviolet photovoltaic cells.

    PubMed

    Yang, Xun; Shan, Chong-Xin; Lu, Ying-Jie; Xie, Xiu-Hua; Li, Bing-Hui; Wang, Shuang-Peng; Jiang, Ming-Ming; Shen, De-Zhen

    2016-02-15

    Photovoltaic cells have been fabricated from p-GaN/MgO/n-ZnO structures. The photovoltaic cells are transparent to visible light and can transform ultraviolet irradiation into electrical signals. The efficiency of the photovoltaic cells is 0.025% under simulated AM 1.5 illumination conditions, while it can reach 0.46% under UV illumination. By connecting several such photovoltaic cells in a series, light-emitting devices can be lighting. The photovoltaic cells reported in this Letter may promise the applications in glass of buildings to prevent UV irradiation and produce power for household appliances in the future. PMID:26872163

  12. Aluminium alloyed iron-silicide/silicon solar cells: A simple approach for low cost environmental-friendly photovoltaic technology

    PubMed Central

    Kumar Dalapati, Goutam; Masudy-Panah, Saeid; Kumar, Avishek; Cheh Tan, Cheng; Ru Tan, Hui; Chi, Dongzhi

    2015-01-01

    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/cm2, 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. PMID:26632759

  13. The NASA-Lewis terrestrial photovoltaics program. [solar cell power system for weather station

    NASA Technical Reports Server (NTRS)

    Bernatowicz, D. T.

    1973-01-01

    Research and technology efforts on solar cells and arrays having relevance to terrestrial uses are outline. These include raising cell efficiency, developing the FEP-covered module concept, and exploring low cost cell concepts. Solar cell-battery power systems for remote weather stations have been built to demonstrate the capabilities of solar cells for terrestrial applications.

  14. The effect of the low Earth orbit environment on space solar cells: Results of the advanced photovoltaic experiment (S0014)

    NASA Technical Reports Server (NTRS)

    Brinker, David J.; Hickey, John R.

    1992-01-01

    The Advanced Photovoltaic Experiment (APEX), containing over 150 solar cells and sensors, was designed to generate laboratory reference standards as well as to explore the durability of a wide variety of space solar cells. Located on the leading edge of the Long Duration Exposure Facility (LDEF), APEX received the maximum possible dosage of atomic oxygen and ultraviolet radiation, as well as enormous numbers of impacts from micrometeoroids and debris. The effect of the low earth orbital (LEO) environment on the solar cells and materials of APEX will be discussed in this paper. The on-orbit performance of the solar cells, as well as a comparison of pre- and postflight laboratory performance measurements, will be presented.

  15. Enhanced photovoltaic performance of dye-sensitized solar cell using composite photoanode on 3D electrode

    NASA Astrophysics Data System (ADS)

    Lim, Chiew Keat; Huang, Hui; Tse, Man Siu; Tan, Ooi Kiang

    2013-12-01

    For dye-sensitized solar cell (DSSC), an efficient transport of electron from the dye sensitizer through the mesoporous oxide layer and to be collected by electrode is crucial for high photovoltaic conversion efficiency. In this work, two novel approaches were developed in DSSC fabrication to improve the overall photovoltaic performance. The concurrent improvement in the charge transport property and light harvesting efficiency was achieved by incorporating N-doped TiO2 in the mesoporous TiO2 layer of the photoanode. These N-doped TiO2 (TiNxOy) was formed by using the single step thermal oxidation of Titanium Nitride (TiN) nanomaterials. At the same time, the 3D electrode with SnO2 nanorods grown on the FTO glass using plasma enhanced chemical vapor deposition (PECVD) system was used to enhance the charge collection efficiency. By combining these two approaches simultaneously, the DSSC with composite TiNxOy-TiO2 photoanode on SnO2 nanorods 3D electrode was successfully fabricated and characterized. As compared to the standard DSSC, an overall increment of 28 % in the conversion efficiency was achieved. Higher incident photon-current conversion efficiency (IPCE) values were also obtained, specifically for the region 400 - 500 nm due to the cosensitization effect of N-doped TiO2. Efficient transfer of electron due to the decrease in charge transfer resistance at the mesoporous oxide/dye/electrolyte interface was observed from electrochemical impedance spectroscopy (EIS) measurement. With the use of SnO2 nanorods, the adhesion between the mesoporous TiO2/FTO was enhanced and the transit time of a photogenerated electron through the mesoporous layer before being collected at the FTO electrode was significantly reduced by 50 %.

  16. The JPL space photovoltaic program. [energy efficient so1 silicon solar cells for space applications

    NASA Technical Reports Server (NTRS)

    Scott-Monck, J. A.

    1979-01-01

    The development of energy efficient solar cells for space applications is discussed. The electrical performance of solar cells as a function of temperature and solar intensity and the influence of radiation and subsequent thermal annealing on the electrical behavior of cells are among the factors studied. Progress in GaAs solar cell development is reported with emphasis on improvement of output power and radiation resistance to demonstrate a solar cell array to meet the specific power and stability requirements of solar power satellites.

  17. Solar Glitter -- Microsystems Enabled Photovoltaics

    NASA Astrophysics Data System (ADS)

    Nielson, Gregory N.

    2012-02-01

    Many products have significantly benefitted from, or been enabled by, the ability to manufacture structures at an ever decreasing length scale. Obvious examples of this include integrated circuits, flat panel displays, micro-scale sensors, and LED lighting. These industries have benefited from length scale effects in terms of improved performance, reduced cost, or new functionality (or a combination of these). In a similar manner, we are working to take advantage of length scale effects that exist within solar photovoltaic (PV) systems. While this is a significant step away from traditional approaches to solar power systems, the benefits in terms of new functionality, improved performance, and reduced cost for solar power are compelling. We are exploring scale effects that result from the size of the solar cells within the system. We have developed unique cells of both crystalline silicon and III-V materials that are very thin (5-20 microns thick) and have very small lateral dimensions (on the order of hundreds of microns across). These cells minimize the amount of expensive semiconductor material required for the system, allow improved cell performance, and provide an expanded design space for both module and system concepts allowing optimized power output and reduced module and balance of system costs. Furthermore, the small size of the cells allows for unique high-efficiency, high-flexibility PV panels and new building-integrated PV options that are currently unavailable. These benefits provide a pathway for PV power to become cost competitive with grid power and allow unique power solutions independent of grid power.

  18. Effect of potassium iodide on luminescent and photovoltaic properties of organic solar cells P3HT-PCBM

    NASA Astrophysics Data System (ADS)

    Ibrayev, N. Kh; Afanasyev, D. A.; Zhapabaev, K. A.

    2016-02-01

    It has been investigated spectral-luminescence properties of polymer films, doped with potassium iodide (KI). Using of KI didn't lead to the gradual changes of optical density of polymer films and the range of band gap semiconductor polymer P3HT. The fluorescence intensity of P3HT decreased and changed by use of KI. Using of 1% KI in polymer leaded to decrease of fluorescence lifetime. Influence of heavy atom on photovoltaic effect of organic solar cells has been investigated. 1% of KI in polymer film leaded to decrease of Isc and slightly decrease of Uoc. Investigation shows that magnetic field does not affect on photovoltaic properties of cells P3HT-PCBM. Magnetic field increased of open circuit voltage and short circuit current of solar cells with 1% of KI. Study of electrical impedance of cells revealed the magnetic sensivity of solar cells with KI additives. The lifetime of free charge carriers increased in the magnetic field for solar cells with KI additives.

  19. Advancements in n-Type Base Crystalline Silicon Solar Cells and Their Emergence in the Photovoltaic Industry

    PubMed Central

    ur Rehman, Atteq; Lee, Soo Hong

    2013-01-01

    The p-type crystalline silicon wafers have occupied most of the solar cell market today. However, modules made with n-type crystalline silicon wafers are actually the most efficient modules up to date. This is because the material properties offered by n-type crystalline silicon substrates are suitable for higher efficiencies. Properties such as the absence of boron-oxygen related defects and a greater tolerance to key metal impurities by n-type crystalline silicon substrates are major factors that underline the efficiency of n-type crystalline silicon wafer modules. The bi-facial design of n-type cells with good rear-side electronic and optical properties on an industrial scale can be shaped as well. Furthermore, the development in the industrialization of solar cell designs based on n-type crystalline silicon substrates also highlights its boost in the contributions to the photovoltaic industry. In this paper, a review of various solar cell structures that can be realized on n-type crystalline silicon substrates will be given. Moreover, the current standing of solar cell technology based on n-type substrates and its contribution in photovoltaic industry will also be discussed. PMID:24459433

  20. Photovoltaic cell assembly

    DOEpatents

    Beavis, Leonard C.; Panitz, Janda K. G.; Sharp, Donald J.

    1990-01-01

    A photovoltaic assembly for converting high intensity solar radiation into lectrical energy in which a solar cell is separated from a heat sink by a thin layer of a composite material which has excellent dielectric properties and good thermal conductivity. This composite material is a thin film of porous Al.sub.2 O.sub.3 in which the pores have been substantially filled with an electrophoretically-deposited layer of a styrene-acrylate resin. This composite provides electrical breakdown strengths greater than that of a layer consisting essentially of Al.sub.2 O.sub.3 and has a higher thermal conductivity than a layer of styrene-acrylate alone.

  1. Photovoltaic properties of high efficiency plastic dye-sensitized solar cells employing interparticle binding agent ``nanoglue''

    NASA Astrophysics Data System (ADS)

    Li, Yuelong; Yoo, Kicheon; Lee, Doh-Kwon; Kim, Jin Young; Kim, Honggon; Kim, Bongsoo; Ko, Min Jae

    2013-05-01

    An interparticle binding agent, or nanoglue, was synthesized by a sol-gel process, which facilitated the preparation of well-interconnected TiO2 electrodes at low-temperatures for plastic dye-sensitized solar cells. The viscosity of the nanoglue-based pastes was seven times higher than that obtained in pastes without any nanoglue. The increased viscosity was sufficiently high enough for coating thick films to fabricate TiO2 electrodes. The structural and photovoltaic properties of the films were extensively investigated by varying the amounts of nanoglue. A reduced pore size and greatly enhanced surface area were observed in the nanoglue-based films. Improved interparticle connectivity, resulting in faster electron transport, was confirmed by photocurrent transient spectroscopy and electrochemical impedance measurements of the nanoglue-based films. The electron diffusion length and charge collection efficiency were also enhanced in these nanoglue-based films. A maximum conversion efficiency of 5.43% was achieved in films containing 20 wt% nanoglue fabricated on a plastic substrate under one-sun illumination, even without any additional treatment.

  2. Strains and photovoltaic response in Ta-sputtered Si metal-insulator-semiconductor solar cells

    NASA Astrophysics Data System (ADS)

    Lalevic, B.; Murty, K.; Ito, T.; Kalman, Z. H.; Weissmann, S.

    1981-07-01

    Deformation by bending of Si or Si-SiO2 wafers is achieved by sputter deposition of tantalum films. Strains induced at Si-SiO2 interface and in Ta films are investigated using a combination of X-ray diffraction, electron diffraction, and transmission electron microscopy. Thin Ta film deposits are found to have predominantly a fcc structure, while thicker films have the normal bcc structure with certain admixture of fcc. Film strains generated by the coexistence of the polymorph structure are accommodated by formation of misfit dislocations at the film-Si substrate interface. The effect of the induced stress on the electronic parameters characterizing the Si-SiO2 interface is studied in the metal-oxide-semiconductor structure, and for the effect on photovoltaic response a metal-insulator-semiconductor solar cell configuration is used. Large changes with increasing stress are observed in the values of recombination time, capture cross section, and diffusion length and in sharply decreased conversion efficiency, fill factor, open-circuit voltage, and short-circuit current.

  3. You're a What? Solar Photovoltaic Installer

    ERIC Educational Resources Information Center

    Torpey, Elka Maria

    2009-01-01

    This article talks about solar photovoltaic (PV) installer and features Rebekah Hren, a solar PV installer who puts solar panels on roofs and in other sunny places to turn the sun's power into electricity. Hren enjoys promoting renewable energy, in part because it's an emerging field. In solar PV systems, solar cells--devices that convert sunlight…

  4. Effect of Substrate Temperature on the Photovoltaic Properties of a CdS/CdTe Solar Cell

    NASA Astrophysics Data System (ADS)

    Uda, Hiroshi; Ikegami, Seiji; Sonomura, Hajimu

    1990-10-01

    Structural and electrical properties of CdTe thin films prepared by the conventional vacuum evaporation method were studied. Photovoltaic properties of thin-film CdS (chemical-solution-deposited)/CdTe (vacuum-evaporated) solar cells were also investigated. The crystal structure of CdTe films deposited on the CdS films at the substrate temperature of 300˜ 520°C was of the zincblende type with a preferential orientation of the (111) plane parallel to the substrate. The dark resistivity of the CdTe films deposited on the glass substrates was about 107 Ωcm. Illumination caused the resistivity decrease of the films by about two orders of magnitude. The conversion efficiency of the CdS/CdTe solar cells increased with increasing substrate temperature. The present thin-film CdS/CdTe solar cell showed a conversion efficiency of greater than 5%.

  5. Dye sensitized photovoltaic miniaturized solar cells, used as optical sensors for line of sight detection

    NASA Astrophysics Data System (ADS)

    Cesar, Cortes Torres Carlos; Sampei, Kota; Miho, Ogawa; Masataka, Ozawa; Norihisa, Miki

    2014-11-01

    Dye sensitized photovoltaic devices have been studied as transparent and low-cost solar cells. Our group have miniaturized the cells and used them as transparent optical sensors. This paper reports the design and fabrication of the cells and avoids the cross talk among cells, which was found recently and such effect provokes hardware instability. We use these optical sensors as an eye tracking device. The sensor array detects the difference in the intensity of light reflected from the pupil and the sclera and then determines the pupil position. Each sensor consists of two electrodes and electrolyte; hence our device conformed by only four semi-circular shaped sensors on eyeglasses can detect the view angle in both horizontal and vertical directions. Manufacturing process gives us freedom to easily re-arrange, add or remove sensors. In our prior work we had good performance in stand-alone configuration. We used specialized equipment from National Instruments for our measurements. However we found that: A cell is not 100% independent from the others, is affected by the absence or presence of light at the neighbour cells. When our device is connected to other electronic devices (for data processing), all cells have the same voltage among them; therefore, all cells behave the same way when any of them is affected by light. The root cause is, due to all sensors were interconnected via a micro channel and filled with electrolyte, due to its conductive properties, electrolyte does neither need electrodes nor physical paths to conduct electricity, so it creates a liquid wire between sensors, hence the gap between them become inexistent, consequently when our device is connected to other electronic devices, due to this unique channel and by sharing a common electronic ground, this connection provokes the voltage to be the same among all sensors in the array. Our device becomes four separate voltage lines in a parallel circuit. The device was also in short circuit provoked

  6. Influence of VB group doped TiO2 on photovoltaic performance of dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Liu, Jia; Duan, Yandong; Zhou, Xiaowen; Lin, Yuan

    2013-07-01

    Dye-sensitized solar cell with VB group (vanadium (V), niobium (Nb) and tantalum (Ta)) doped TiO2 prepared by hydrothermal method shows a higher photovoltaic efficiency compared with the undoped TiO2. All the VB doping shift the flat band potential positively and increase the doping density which is investigated by Mott-Schottky plot. The positive shift of flat band potential improves the driving force of injecting electron from the LUMO of dye to the conduction band of TiO2 and the photocurrent. On the other hand, the increase of doping density accelerates transfer rate of electrons in TiO2 than the un-doped, which is confirmed by intensity-modulated photocurrent. V-, Nb-, Ta-doped TiO2 exhibited photovoltaic performance with 7.80%, 8.33%, 8.18%, respectively, compared with that of the cells based on pure TiO2 (7.42%).

  7. Indium phosphide solar cell research in the United States: Comparison with non-photovoltaic sources

    NASA Technical Reports Server (NTRS)

    Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.

    1989-01-01

    Highlights of the InP solar cell research program are presented. Homojunction cells with efficiencies approaching 19 percent are demonstrated, while 17 percent is achieved for ITO/InP cells. The superior radiation resistance of the two latter cell configurations over both Si and GaAs cells has been shown. InP cells aboard the LIPS3 satellite show no degradation after more than a year in orbit. Computed array specific powers are used to compare the performance of an InP solar cell array to solar dynamic and nuclear systems.

  8. Eco green flexible hybrid photovoltaic-thermoelectric solar cells with nanoimprint technology and roll-to-roll manufacturing

    NASA Astrophysics Data System (ADS)

    Varadan, Vijay K.; Choi, Sang H.

    2010-04-01

    This paper explores the technical and commercial feasibility of nanotechnology based, high-efficiency, photovoltaic-thermoelectric hybrid solar cells as an environmentally-friendly, renewable energy source for residential and commercial buildings. To convert as much as possible of the usable photovoltaic (58% of the Energy Density) and thermoelectric (42% of the Energy Density) solar spectrum into electricity, a hybrid multilayer system is presented which comprises of 1) carbon nanotube (CNT) embedded in conducting polymers such as P3HT (poly(3-hexylthiophene) or P3OT (poly3-octylthiophene), 2) 3D gold nanostructures exhibiting plasmonic resonances for energy conversion, 3) nanoantenna architecture to capture IR energy, 4) a composite of Bi2Te3, SiGe nanocrystals and Au nanoshells as thermoelectric energy conversion layer, 5) configuration of the above items engineered in the form of meta-material designs that by virtue of their 3D structures ensure that incident light is neither reflected nor transmitted, but is rather all absorbed, 6) a multilayer arrangement of the above layers in a fractal architecture to capture all the wavelengths from 200 to 3000 nm8 and the matching electronic interface for each layer. The roll-to-roll manufacturing method presented will enable economical large-scale production of solar panels. This potentially transformational technology has the ability to replace the Si solar cell technology by reducing costs from 0.18/KWh to 0.003/KWh while introducing a more environmentally-friendly manufacturing process.

  9. See-through amorphous silicon solar cells with selectively transparent and conducting photonic crystal back reflectors for building integrated photovoltaics

    SciTech Connect

    Yang, Yang; O’Brien, Paul G.; Ozin, Geoffrey A. E-mail: kherani@ecf.utoronto.ca; Kherani, Nazir P. E-mail: kherani@ecf.utoronto.ca

    2013-11-25

    Thin semi-transparent hydrogenated amorphous silicon (a-Si:H) solar cells with selectively transparent and conducting photonic crystal (STCPC) back-reflectors are demonstrated. Short circuit current density of a 135 nm thick a-Si:H cell with a given STCPC back-reflector is enhanced by as much as 23% in comparison to a reference cell with an ITO film functioning as its rear contact. Concurrently, solar irradiance of 295 W/m{sup 2} and illuminance of 3480 lux are transmitted through the cell with a given STCPC back reflector under AM1.5 Global tilt illumination, indicating its utility as a source of space heating and lighting, respectively, in building integrated photovoltaic applications.

  10. Solar cells

    NASA Astrophysics Data System (ADS)

    Cuquel, A.; Roussel, M.

    The physical and electronic characteristics of solar cells are discussed in terms of space applications. The principles underlying the photovoltaic effect are reviewed, including an analytic model for predicting the performance of individual cells and arrays of cells. Attention is given to the effects of electromagnetic and ionizing radiation, micrometeors, thermal and mechanical stresses, pollution and degassing encountered in space. The responses of different types of solar cells to the various performance-degrading agents are examined, with emphasis on techniques for quality assurance in the manufacture and mounting of Si cells.

  11. Photovoltaics

    NASA Astrophysics Data System (ADS)

    Seippel, R. G.

    This book attempts to provide the reader with a cursory look at solar energy from a quarry of quartz to a sophisticated solar system. The progression of the theories of light is discussed along with the progression of photoelectricity, light rays, the optical spectrum, light reception, photodetection, aspects of photometry and radiometry, preferred terms in radiometric measurement, semiconductor physics, and light energy availability. Other subjects explored are related to manufacturing processes, photovoltaic materials, crystal growing, slicing techniques, wafer finishing, solar cell fabrication, photovoltaic cell types, concentrators, module fabrication, problems of quality assurance, photovoltaic systems, and the photovoltaics hierarchy. Attention is given to the polycrystalline cell, insulator cells, cadmium sulfide cells, amorphous silicon cells, an electrochemical cell, and the low-cost solar array project.

  12. Improve photovoltaic performance of titanium dioxide nanorods based dye-sensitized solar cells by Ca-doping

    SciTech Connect

    Li, Weixin; Yang, Junyou Zhang, Jiaqi; Gao, Sheng; Luo, Yubo; Liu, Ming

    2014-09-15

    Highlights: • TiO{sub 2} nanorods doped with Ca ions were synthesized by one-step hydrothermal method. • The flat band edge of rutile TiO{sub 2} shifted positively via Ca-doping. • The photoelectric conversion efficiency of dye-sensitized solar cells (DSSCs) based on TiO{sub 2} electrode was much enhanced by Ca-doping. • A relatively high open circuit voltage was obtained by adopting Ca-doped TiO{sub 2} nanorods electrode. - Abstract: Ca-doped TiO{sub 2} nanorod arrays were prepared via the one-step hydrothermal method successfully, and the effect of Ca ions content on the photovoltaic conversion efficiency of dye-sensitized solar cells has been fully discussed in the paper. Although no obvious change on the microstructure and morphology was observed by field emission scanning electron microscope and transmission electron microscope for the Ca-doped samples, the results of X-ray diffraction and X-ray photoelectron spectroscopy confirmed that Ti{sup 4+} was substituted with Ca{sup 2+} successfully. UV–vis spectroscopy results revealed that the flat band edge shifted positively by Ca ions doping. The photovoltaic conversion efficiency of the dye-sensitized solar cells based on the 2 mol% Ca-doped TiO{sub 2} electrode was 43% higher than that of the undoped one due to the less recombination possibility.

  13. 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.

  14. Development of Silver-Free Silicon Photovoltaic Solar Cells with All-Aluminum Electrodes

    NASA Astrophysics Data System (ADS)

    Sun, Wen-Cheng

    To date, the most popular and dominant material for commercial solar cells is crystalline silicon (or wafer-Si). It has the highest cell efficiency and cell lifetime out of all commercial solar cells. Although the potential of crystalline-Si solar cells in supplying energy demands is enormous, their future growth will likely be constrained by two major bottlenecks. The first is the high electricity input to produce crystalline-Si solar cells and modules, and the second is the limited supply of silver (Ag) reserves. These bottlenecks prevent crystalline-Si solar cells from reaching terawatt-scale deployment, which means the electricity produced by crystalline-Si solar cells would never fulfill a noticeable portion of our energy demands in the future. In order to solve the issue of Ag limitation for the front metal grid, aluminum (Al) electroplating has been developed as an alternative metallization technique in the fabrication of crystalline-Si solar cells. The plating is carried out in a near-room-temperature ionic liquid by means of galvanostatic electrolysis. It has been found that dense, adherent Al deposits with resistivity in the high 10--6 Ω-cm range can be reproducibly obtained directly on Si substrates and nickel seed layers. An all-Al Si solar cell, with an electroplated Al front electrode and a screen-printed Al back electrode, has been successfully demonstrated based on commercial p-type monocrystalline-Si solar cells, and its efficiency is approaching 15%. Further optimization of the cell fabrication process, in particular a suitable patterning technique for the front silicon nitride layer, is expected to increase the efficiency of the cell to ~18%. This shows the potential of Al electroplating in cell metallization is promising and replacing Ag with Al as the front finger electrode is feasible.

  15. White butterflies as solar photovoltaic concentrators

    NASA Astrophysics Data System (ADS)

    Shanks, Katie; Senthilarasu, S.; Ffrench-Constant, Richard H.; Mallick, Tapas K.

    2015-07-01

    Man’s harvesting of photovoltaic energy requires the deployment of extensive arrays of solar panels. To improve both the gathering of thermal and photovoltaic energy from the sun we have examined the concept of biomimicry in white butterflies of the family Pieridae. We tested the hypothesis that the V-shaped posture of basking white butterflies mimics the V-trough concentrator which is designed to increase solar input to photovoltaic cells. These solar concentrators improve harvesting efficiency but are both heavy and bulky, severely limiting their deployment. Here, we show that the attachment of butterfly wings to a solar cell increases its output power by 42.3%, proving that the wings are indeed highly reflective. Importantly, and relative to current concentrators, the wings improve the power to weight ratio of the overall structure 17-fold, vastly expanding their potential application. Moreover, a single mono-layer of scale cells removed from the butterflies’ wings maintained this high reflectivity showing that a single layer of scale cell-like structures can also form a useful coating. As predicted, the wings increased the temperature of the butterflies’ thorax dramatically, showing that the V-shaped basking posture of white butterflies has indeed evolved to increase the temperature of their flight muscles prior to take-off.

  16. White butterflies as solar photovoltaic concentrators.

    PubMed

    Shanks, Katie; Senthilarasu, S; Ffrench-Constant, Richard H; Mallick, Tapas K

    2015-01-01

    Man's harvesting of photovoltaic energy requires the deployment of extensive arrays of solar panels. To improve both the gathering of thermal and photovoltaic energy from the sun we have examined the concept of biomimicry in white butterflies of the family Pieridae. We tested the hypothesis that the V-shaped posture of basking white butterflies mimics the V-trough concentrator which is designed to increase solar input to photovoltaic cells. These solar concentrators improve harvesting efficiency but are both heavy and bulky, severely limiting their deployment. Here, we show that the attachment of butterfly wings to a solar cell increases its output power by 42.3%, proving that the wings are indeed highly reflective. Importantly, and relative to current concentrators, the wings improve the power to weight ratio of the overall structure 17-fold, vastly expanding their potential application. Moreover, a single mono-layer of scale cells removed from the butterflies' wings maintained this high reflectivity showing that a single layer of scale cell-like structures can also form a useful coating. As predicted, the wings increased the temperature of the butterflies' thorax dramatically, showing that the V-shaped basking posture of white butterflies has indeed evolved to increase the temperature of their flight muscles prior to take-off. PMID:26227341

  17. White butterflies as solar photovoltaic concentrators

    PubMed Central

    Shanks, Katie; Senthilarasu, S.; ffrench-Constant, Richard H.; Mallick, Tapas K.

    2015-01-01

    Man’s harvesting of photovoltaic energy requires the deployment of extensive arrays of solar panels. To improve both the gathering of thermal and photovoltaic energy from the sun we have examined the concept of biomimicry in white butterflies of the family Pieridae. We tested the hypothesis that the V-shaped posture of basking white butterflies mimics the V-trough concentrator which is designed to increase solar input to photovoltaic cells. These solar concentrators improve harvesting efficiency but are both heavy and bulky, severely limiting their deployment. Here, we show that the attachment of butterfly wings to a solar cell increases its output power by 42.3%, proving that the wings are indeed highly reflective. Importantly, and relative to current concentrators, the wings improve the power to weight ratio of the overall structure 17-fold, vastly expanding their potential application. Moreover, a single mono-layer of scale cells removed from the butterflies’ wings maintained this high reflectivity showing that a single layer of scale cell-like structures can also form a useful coating. As predicted, the wings increased the temperature of the butterflies’ thorax dramatically, showing that the V-shaped basking posture of white butterflies has indeed evolved to increase the temperature of their flight muscles prior to take-off. PMID:26227341

  18. Role of bromine doping on the photovoltaic properties and microstructures of CH3NH3PbI3 perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Suzuki, Atsushi; Okada, Hiroshi; Oku, Takeo

    2016-02-01

    Organic-inorganic hybrid heterojunction solar cells containing CH3NH3PbI3 perovskite compound were fabricated using mesoporous TiO2 as the electronic transporting layer and spirobifluorence as the hole-transporting layer. The purpose of the present study is to investigate role of bromine (Br) doping on the photovoltaic properties and microstructure of CH3NH3PbI3 perovskite solar cells. Photovoltaic, optical properties and microstructures of perovskite-based solar cells were investigated. The X-ray diffraction identified crystal structure of the perovskite layer doped with Br in the solar cell. Scanning electron microscopy observation showed a different behavior of surface morphology and the perovskite crystal structure on the TiO2 mesoporous structure depending on extent amount of hydrogen doping of Br. The role of bromide halogen doping on the perovskite crystal structure and photovoltaic properties was due to improvement of carrier mobility, optimization of electron structure, band gap related with the photovoltaic parameters of Voc, Jsc and η. Energy diagram and photovoltaic mechanism of the perovskite solar cells varied with halogen doping was discussed by experimental results.

  19. Three-terminal heterojunction bipolar transistor solar cell for high-efficiency photovoltaic conversion

    PubMed Central

    Martí, A.; Luque, A.

    2015-01-01

    Here we propose, for the first time, a solar cell characterized by a semiconductor transistor structure (n/p/n or p/n/p) where the base–emitter junction is made of a high-bandgap semiconductor and the collector is made of a low-bandgap semiconductor. We calculate its detailed-balance efficiency limit and prove that it is the same one than that of a double-junction solar cell. The practical importance of this result relies on the simplicity of the structure that reduces the number of layers that are required to match the limiting efficiency of dual-junction solar cells without using tunnel junctions. The device naturally emerges as a three-terminal solar cell and can also be used as building block of multijunction solar cells with an increased number of junctions. PMID:25902374

  20. Three-terminal heterojunction bipolar transistor solar cell for high-efficiency photovoltaic conversion.

    PubMed

    Martí, A; Luque, A

    2015-01-01

    Here we propose, for the first time, a solar cell characterized by a semiconductor transistor structure (n/p/n or p/n/p) where the base-emitter junction is made of a high-bandgap semiconductor and the collector is made of a low-bandgap semiconductor. We calculate its detailed-balance efficiency limit and prove that it is the same one than that of a double-junction solar cell. The practical importance of this result relies on the simplicity of the structure that reduces the number of layers that are required to match the limiting efficiency of dual-junction solar cells without using tunnel junctions. The device naturally emerges as a three-terminal solar cell and can also be used as building block of multijunction solar cells with an increased number of junctions. PMID:25902374

  1. Solar photovoltaic power systems: an electric utility R & d perspective.

    PubMed

    Demeo, E A; Taylor, R W

    1984-04-20

    Solar photovoltaic technology is receiving increasing attention as a prospective source of bulk, electric utility power within the next 10 to 20 years. Successful development will require solar energy conversion efficiencies of about 15 percent for photovoltaic flat-plate modules, or about 25 percent for photovoltaic cells using highly concentrated sunlight. Three different cell technologies have a better than even chance of achieving these target efficiencies with costs and operating lifetimes that would allow significant use by electric utilities. The challenge for the next decade is to push photovoltaic technology to its physical limits while expanding markets and user confidence with currently available systems. PMID:17734901

  2. Silicon nanowires for photovoltaic solar energy conversion.

    PubMed

    Peng, Kui-Qing; Lee, Shuit-Tong

    2011-01-11

    Semiconductor nanowires are attracting intense interest as a promising material for solar energy conversion for the new-generation photovoltaic (PV) technology. In particular, silicon nanowires (SiNWs) are under active investigation for PV applications because they offer novel approaches for solar-to-electric energy conversion leading to high-efficiency devices via simple manufacturing. This article reviews the recent developments in the utilization of SiNWs for PV applications, the relationship between SiNW-based PV device structure and performance, and the challenges to obtaining high-performance cost-effective solar cells. PMID:20931630

  3. Fabrication and performance analysis of 4-sq cm indium tin oxide/InP photovoltaic solar cells

    NASA Technical Reports Server (NTRS)

    Gessert, T. A.; Li, X.; Phelps, P. W.; Coutts, T. J.; Tzafaras, N.

    1991-01-01

    Large-area photovoltaic solar cells based on direct current magnetron sputter deposition of indium tin oxide (ITO) into single-crystal p-InP substrates demonstrated both the radiation hardness and high performance necessary for extraterrestrial applications. A small-scale production project was initiated in which approximately 50 ITO/InP cells are being produced. The procedures used in this small-scale production of 4-sq cm ITO/InP cells are presented and discussed. The discussion includes analyses of performance range of all available production cells, and device performance data of the best cells thus far produced. Additionally, processing experience gained from the production of these cells is discussed, indicating other issues that may be encountered when large-scale productions are begun.

  4. Tandem Microwire Solar Cells for Flexible High Efficiency Low Cost Photovoltaics

    SciTech Connect

    Atwater, Harry A.

    2015-03-10

    This project has developed components of a waferless, flexible, low-cost tandem multijunction III-V/Si microwire array solar cell technology which combines the efficiency of wafered III-V photovoltaic technologies with the process designed to meet the Sunshot object. The project focused on design of lattice-matched GaAsP/SiGe two junction cell design and lattice-mismatched GaInP/Si tandem cell design. Combined electromagnetic simulation/device physics models using realistic microwire tandem structures were developed that predict >22% conversion efficiency for known material parameters, such as tunnel junction structure, window layer structure, absorber lifetimes and optical absorption and these model indicate a clear path to 30% efficiency for high quality III-V heterostructures. SiGe microwire arrays were synthesized via Cu-catalyzed vapor-liquid-solid (VLS) growth with inexpensive chlorosilane and chlorogermance precursors in an atmospheric pressure reactor. SiGe alloy composition in microwires was found to be limited to a maximum of 12% Ge incorporation during chlorogermane growth, due to the melting of the alloy near the solidus composition. Lattice mismatched InGaP double heterostructures were grown by selective epitaxy with a thermal oxide mask on Si microwire substrates using metallorganic vapor phase epitaxy. Transmission electron microscopy (TEM) analysis confirms the growth of individual step graded layers and a high density of defects near the wire/III-V interface. Selective epitaxy was initiated with a low temperature nucleation scheme under “atomic layer epitaxy” or “flow mediated epitaxy” conditions whereby the Ga and P containing precursors are alternately introduced into the reactor to promote layer-bylayer growth. In parallel to our efforts on conformal GaInP heteroepitaxy on selectively masked Si microwires, we explored direct, axial growth of GaAs on Si wire arrays as another route to a tandem junction architecture. We proposed axial

  5. Enhanced Photovoltaic properties of P3HT/Cr-TiO2 bilayer film heterojunction solar cells

    NASA Astrophysics Data System (ADS)

    Wang, Xiang-Qian; Wang, Jian; Li, Yan; Wang, Cheng-Wei; Hou, Xian; Pan, Zi-Wei; Zhou, Feng

    2013-10-01

    The simple bilayer solar cells, composed of poly (3-hexylthiophene-2,5-diyl) (P3HT) and chromium doped titanium dioxide (Cr-TiO2) nanocrystal films, were fabricated by sol-gel method. The performances of structurally identical polymer-inorganic heterojunction solar cells Cu/Cr-TiO2/P3HT/FTO/Glass with various Cr3+ doping concentration were systematically investigated and compared. The results indicate that the samples' open-circuit voltage is remarkably enhanced from 0.42 V to 0.99 V, and short-circuit photocurrent increases at first and then reduces, with the increase of Cr3+ doping concentration. The enhancement mechanism of photovoltaic properties is discussed in detail.

  6. Microstructures and photovoltaic properties of fullerene-based organic-inorganic hybrid solar cells

    NASA Astrophysics Data System (ADS)

    Oku, T.; Takeda, A.; Nagata, A.; Fujimoto, K.; Akiyama, T.; Suzuki, A.

    2012-03-01

    C60-based bulk heterojunction solar cells were fabricated, and the electronic and optical properties were investigated. C60 were used as n-type semiconductors, and copper oxides, CuInS2 and diamond were used as p-type semiconductors. Electronic structures of the molecules were investigated by molecular orbital calculation, and energy levels of the solar cells were discussed. Nanostructures of the solar cells were investigated by transmission electron microscopy, electron diffraction and X-ray diffraction, which indicated formation of mixed nanocrystals.

  7. Consideration of coordinated solar tracking of an array of compact solar-pumped lasers combined with photovoltaic cells for electricity generation

    NASA Astrophysics Data System (ADS)

    Motohiro, Tomoyoshi; Ichiki, Akihisa; Ichikawa, Tadashi; Ito, Hiroshi; Hasegawa, Kazuo; Mizuno, Shintaro; Ito, Tadashi; Kajino, Tsutomu; Takeda, Yasuhiko; Higuchi, Kazuo

    2015-08-01

    A monochromatic laser light with a photon energy just above the band edge of photovoltaic cells can be converted into electricity with minimal thermal loss. To attain efficient conversion of sunlight to laser light, a coordinated solar tracking system for an array of originally designed compact solar-pumped lasers of 50 mm aperture diameter is being constructed. As for the feasibility of this system, a prototype with a holding capacity of 25 compact solar-pumped lasers has been fabricated. The primary requisite of this system is that the angular accuracy of tracking should be below 1 mrad for all 25 compact solar-pumped lasers to sustain their continuous lasing. To realize this, imperative challenges have been elucidated including thermal expansion under sunlight. A prototype fabricated with its main frame made of Super Invar alloy was found to fulfill the requisite by measurement using a three-dimensional coordinate measuring machine.

  8. Solar cells

    NASA Astrophysics Data System (ADS)

    Treble, F. C.

    1980-11-01

    The history, state of the art, and future prospects of solar cells are reviewed. Solar cells are already competitive in a wide range of low-power applications, and during the 1980's they are expected to become cheaper to run than diesel or gasoline generators, the present mainstay of isolated communities. At this stage they will become attractive for water pumping, irrigation, and rural electrification, particularly in developing countries. With further cost reduction, they may be used to augment grid supplies in domestic, commercial, institutional, and industrial premises. Cost reduction to the stage where photovoltaics becomes economic for large-scale power generation in central stations depends on a technological breakthrough in the development of thin-film cells. DOE aims to reach this goal by 1990, so that by the end of the century about 20% of the estimated annual additions to their electrical generating capacity will be photovoltaic.

  9. Radiation resistance of thin-film solar cells for space photovoltaic power

    NASA Technical Reports Server (NTRS)

    Woodyard, James R.; Landis, Geoffrey A.

    1991-01-01

    Copper indium diselenide, cadmium telluride, and amorphous silicon alloy solar cells have achieved noteworthy performance and are currently being studied for space power applications. Cadmium sulfide cells had been the subject of much effort but are no longer considered for space applications. A review is presented of what is known about the radiation degradation of thin film solar cells in space. Experimental cadmium telluride and amorphous silicon alloy cells are reviewed. Damage mechanisms and radiation induced defect generation and passivation in the amorphous silicon alloy cell are discussed in detail due to the greater amount of experimental data available.

  10. Modeling photovoltaic performance in periodic patterned colloidal quantum dot solar cells.

    PubMed

    Fu, Yulan; Dinku, Abay G; Hara, Yukihiro; Miller, Christopher W; Vrouwenvelder, Kristina T; Lopez, Rene

    2015-07-27

    Colloidal quantum dot (CQD) solar cells have attracted tremendous attention mostly due to their wide absorption spectrum window and potentially low processability cost. The ultimate efficiency of CQD solar cells is highly limited by their high trap state density. Here we show that the overall device power conversion efficiency could be improved by employing photonic structures that enhance both charge generation and collection efficiencies. By employing a two-dimensional numerical model, we have calculated the characteristics of patterned CQD solar cells based of a simple grating structure. Our calculation predicts a power conversion efficiency as high as 11.2%, with a short circuit current density of 35.2 mA/cm2, a value nearly 1.5 times larger than the conventional flat design, showing the great potential value of patterned quantum dot solar cells. PMID:26367680

  11. Review of the workshop on low-cost polysilicon for terrestrial photovoltaic solar cell applications

    NASA Technical Reports Server (NTRS)

    Lutwack, R.

    1986-01-01

    Topics reviewed include: polysilicon material requirements; effects of impurities; requirements for high-efficiency solar cells; economics; development of silane processes; fluidized-bed processor development; silicon purification; and marketing.

  12. A 24.4% solar to hydrogen energy conversion efficiency by combining concentrator photovoltaic modules and electrochemical cells

    NASA Astrophysics Data System (ADS)

    Nakamura, Akihiro; Ota, Yasuyuki; Koike, Kayo; Hidaka, Yoshihide; Nishioka, Kensuke; Sugiyama, Masakazu; Fujii, Katsushi

    2015-10-01

    The highest efficiency of 24.4% for the solar-to-hydrogen (STH) energy conversion was obtained in an outdoor field test by combining concentrator photovoltaic (CPV) modules with InGaP/GaAs/Ge three-junction cells and polymer-electrolyte electrochemical (EC) cells. The high efficiency was obtained by using the high-efficiency CPV modules (∼31% under the present operation conditions) and the direct connection between the CPV modules and the EC cells with an almost optimized number of elements in series. The STH efficiency bottleneck was clarified to be the efficiency of the CPV modules, the over-potential of the EC cells, and matching of the operation point to the maximal-power point of the CPV modules.

  13. Photovoltaic and photoelectrochemical conversion of solar energy.

    PubMed

    Grätzel, Michael

    2007-04-15

    The Sun provides approximately 100,000 terawatts to the Earth which is about 10000 times more than the present rate of the world's present energy consumption. Photovoltaic cells are being increasingly used to tap into this huge resource and will play a key role in future sustainable energy systems. So far, solid-state junction devices, usually made of silicon, crystalline or amorphous, and profiting from the experience and material availability resulting from the semiconductor industry, have dominated photovoltaic solar energy converters. These systems have by now attained a mature state serving a rapidly growing market, expected to rise to 300 GW by 2030. However, the cost of photovoltaic electricity production is still too high to be competitive with nuclear or fossil energy. Thin film photovoltaic cells made of CuInSe or CdTe are being increasingly employed along with amorphous silicon. The recently discovered cells based on mesoscopic inorganic or organic semiconductors commonly referred to as 'bulk' junctions due to their three-dimensional structure are very attractive alternatives which offer the prospect of very low cost fabrication. The prototype of this family of devices is the dye-sensitized solar cell (DSC), which accomplishes the optical absorption and the charge separation processes by the association of a sensitizer as light-absorbing material with a wide band gap semiconductor of mesoporous or nanocrystalline morphology. Research is booming also in the area of third generation photovoltaic cells where multi-junction devices and a recent breakthrough concerning multiple carrier generation in quantum dot absorbers offer promising perspectives. PMID:17272237

  14. Monte Carlo Simulations of Luminescent Solar Concentrators with Front-Facing Photovoltaic Cells for Building Integrated Photovoltaics

    NASA Astrophysics Data System (ADS)

    Leow, Shin; Corrado, Carley; Osborn, Melissa; Carter, Sue

    2013-03-01

    Luminescent solar concentrators (LSCs) have the ability to receive light from a wide range of angles and concentrate the captured light on to small photo active areas. This enables LSCs to be integrated more extensively into buildings as windows and wall claddings on top of roof installations. LSCs with front facing PV cells collect both direct and concentrated light ensuring a gain factor greater than one. It also allows for flexibility in determining the placement and percentage coverage of PV cells when designing panels to balance reabsorption losses, power output and the level of concentration desired. A Monte-Carlo ray tracing program was developed to study the transport of photons and loss mechanisms in LSC panels and aid in design optimization. The program imports measured absorption/emission spectra and transmission coefficients as simulation parameters. Interactions of photons with the LSC panel are determined by comparing calculated probabilities with random number generators. Simulation results reveal optimal panel dimensions and PV cell layouts to achieve maximum power output.

  15. Optoelectronic and Photovoltaic Performances of Pyridine Based Monomer and Polymer Capped ZnO Dye-Sensitized Solar Cells.

    PubMed

    Singh, Satbir; Raj, Tilak; Singh, Amarpal; Kaur, Navneet

    2016-06-01

    The present research work describes the comparative analysis and performance characteristics of 4-pyridine based monomer and polymer capped ZnO dye-sensitized solar cells. The N, N-dimethyl-N4-((pyridine-4yl)methylene) propaneamine (4,monomer) and polyamine-4-pyridyl Schiff base (5, polymer) dyes were synthesized through one step condensation reaction between 4-pyridinecarboxaldehyde 1 and N, N-dimethylpropylamine 2/polyamine 3. Products obtained N, N-dimethyl-N4-((pyridine-4yl)methylene)propaneamine (4) and polyamine-4-pyridyl Schiff base (5) were purified and characterized using 1H, 13C NMR, mass, IR and CHN spectroscopy. Both the dyes 4 and 5 were further coated over ZnO nanoparticles and characterized using SEM, DLS and XRD analysis. Absorption profile and emission profile was monitored using fluorescence and UV-Vis absorption spectroscopy. A thick layer of these inbuilt dye linked ZnO nanoparticles of dyes (4) and (5) was pasted on one of the conductive side of ITO glass followed with a liquid electrolyte and counter electrode of the same conductive glass. Polyamine-4-pyridyl Schiff base polymer (5) decorated dye sensitized solar cell has shown better exciting photovoltaic properties in the form of short circuit current density (J(sc) = 6.3 mA/cm2), open circuit photo voltage (V(oc) = 0.7 V), fill factor (FF = 0.736) than monomer decorated dye sensitized solar cell. Polymer dye (5) based ZnO solar cell has shown a maximum solar power to electrical conversion efficiency of 3.25%, which is enhanced by 2.16% in case of monomer dye based ZnO solar cell under AM 1.5 sun illuminations. PMID:27427659

  16. High-resolution mapping of the energy conversion efficiency of solar cells and silicon photodiodes in photovoltaic mode

    NASA Astrophysics Data System (ADS)

    Cemine, Vernon Julius; Sarmiento, Raymund; Blanca, Carlo Mar

    2008-11-01

    We demonstrate an optical technique to derive the two-dimensional energy conversion efficiency ( ηCE), fill factor (FF) and external quantum efficiency ( ηQE) distributions across the surface of photovoltaic devices. A compact, inexpensive optical-feedback laser diode microscope is constructed to acquire the confocal reflectance and efficiency maps enabling the observation of the local parametric behavior in silicon photodiodes in photovoltaic mode and single-junction solar cells. The ηCE and ηQE distributions are greatly influenced by local parasitic resistances that depend on laser irradiance. These parasitic resistances decrease the ηCE and ηQE values with distance from the contact electrode at high laser irradiance. The optical technique enables microscopic comparison of ηCE and ηQE within the pn-overlay region of the photodiode sample, revealing its optimization for photodetection rather than power generation. The technique also elucidates the decreasing local ηCE of the solar cell under intense irradiation.

  17. Dual functions of YF3:Eu3+ for improving photovoltaic performance of dye-sensitized solar cells

    PubMed Central

    Wu, Jihuai; Wang, Jiangli; Lin, Jianming; Xiao, Yaoming; Yue, Gentian; Huang, Miaoliang; Lan, Zhang; Huang, Yunfang; Fan, Leqing; Yin, Shu; Sato, Tsugio

    2013-01-01

    In order to enhance the photovoltaic performance of dye-sensitized solar cell (DSSC), a novel design is demonstrated by introducing rare-earth compound europium ion doped yttrium fluoride (YF3:Eu3+) in TiO2 film in the DSSC. As a conversion luminescence medium, YF3:Eu3+ transfers ultraviolet light to visible light via down-conversion, and increases incident harvest and photocurrent of DSSC. As a p-type dopant, Eu3+ elevates the Fermi level of TiO2 film and thus heightens photovoltage of the DSSC. The conversion luminescence and p-type doping effect are demonstrated by photoluminescence spectra and Mott-Schottky plots. When the ratio of YF3:Eu3+/TiO2 in the doping layer is optimized as 5 wt.%, the light-to-electric energy conversion efficiency of the DSSC reaches 7.74%, which is increased by 32% compared to that of the DSSC without YF3:Eu3+ doping. Double functions of doped rare-earth compound provide a new route for enhancing the photovoltaic performance of solar cells. PMID:23792787

  18. The high intensity solar cell - Key to low cost photovoltaic power

    NASA Technical Reports Server (NTRS)

    Sater, B. L.; Goradia, C.

    1975-01-01

    This paper discusses the problems associated with conventional solar cells at high intensities and presents the design considerations and performance characteristics of the 'high intensity' (HI) solar cell which appears to eliminate the major problems. Test data obtained at greater than 250 AM1 suns gave a peak output power density of 2 W per sq cm at an efficiency exceeding 6% with an unoptimized cell operating at over 100 C. It appears that operation at 1000 AM1 suns at efficiencies greater than 10% is possible. At 1000 AM1 suns and 10% efficiency, the HI cell manufacturing cost is estimated to be $0.25/watt, with multi-megawatt annual production capability already existing within the industrial sector. A high intensity solar system was also analyzed to determine its cost effectiveness and to assess the benefits of further improving HI cell efficiency.

  19. High-efficiency thin and compact concentrator photovoltaics with micro-solar cells directly attached to a lens array.

    PubMed

    Hayashi, Nobuhiko; Inoue, Daijiro; Matsumoto, Mitsuhiro; Matsushita, Akio; Higuchi, Hiroshi; Aya, Youichirou; Nakagawa, Tohru

    2015-06-01

    We propose a thin and compact concentrator photovoltaic (CPV) module, about 20 mm thick, one tenth thinner than those of conventional CPVs that are widely deployed for mega-solar systems, to broaden CPV application scenarios. We achieved an energy conversion efficiency of 37.1% at a module temperature of 25 °C under sunlight irradiation optimized for our module. Our CPV module has a lens array consisting of 10 mm-square unit lenses and micro solar cells that are directly attached to the lens array, to reduce the focal length of the concentrator and to reduce optical losses due to reflection. The optical loss of the lens in our module is about 9.0%, which is lower than that of conventional CPV modules with secondary optics. This low optical loss enables our CPV module to achieve a high energy conversion efficiency. PMID:26072884

  20. Enhancement in the photovoltaic performance of a dye-sensitized solar cell by an optimized ZnO barrier layer

    NASA Astrophysics Data System (ADS)

    Seo, Hyunwoong; Son, Min-Kyu; Kim, Jin-Kyoung; Shin, Inyoung; Prabakar, K.; Kim, Hee-Je

    2010-05-01

    A dye-sensitized solar cell (DSC) has been considered as a strong alternative to conventional photovoltaic devices based on semiconductors such as silicon or compound semiconductors. The barrier layer functioned by the use of an electrode consisting of two different conduction band potentials is very effective in increasing the photovoltaic performance of a DSC. Especially, zinc oxide (ZnO) is very effective as a barrier layer because it has a higher energy level of the conduction band than TiO2and good contact with TiO2 and dye molecules. We tried to fabricate the ZnO barrier layer using zinc acetate aqueous solution by the dip-coating method, although ZnO film is usually fabricated by chemical vapor deposition or sputter deposition. The experimental parameters were optimized to achieve an effective ZnO barrier layer. The electrochemical impedance spectroscopy and x-ray diffraction pattern were measured to analyze the ZnO layer. The photovoltaic performance of a completed DSC with an optimized ZnO barrier layer was measured and compared with that of a conventional DSC. Consequently, a DSC with a ZnO barrier layer had an increased VOC up to 0.85 V and an enhanced efficiency of 4.05%.

  1. Radioisotope thermal photovoltaic application of the GaSb solar cell

    NASA Technical Reports Server (NTRS)

    Morgan, M. D.; Horne, W. E.; Day, A. C.

    1991-01-01

    An examination of a RTVP (radioisotopic thermophotovoltaic) conceptual design has shown a high potential for power densities well above those achievable with radioisotopic thermoelectric generator (RTG) systems. An efficiency of 14.4 percent and system specific power of 9.25 watts/kg were predicted for a system with sixteen GPHS (general purpose heat source) sources operating at 1100 C. The models also showed a 500 watt system power by the strontium-90 isotope at 1200 C at an efficiency of 17.0 percent and a system specific power of 11.8 watts/kg. The key to this level of performance is a high-quality photovoltaic cell with narrow bandgap and a reflective rear contact. Recent work at Boeing on GaSb cells and transparent back GaAs cells indicate that such a cell is well within reach.

  2. Effects of Bulky Substituents of Push-Pull Porphyrins on Photovoltaic Properties of Dye-Sensitized Solar Cells.

    PubMed

    Higashino, Tomohiro; Kawamoto, Kyosuke; Sugiura, Kenichi; Fujimori, Yamato; Tsuji, Yukihiro; Kurotobi, Kei; Ito, Seigo; Imahori, Hiroshi

    2016-06-22

    To evaluate the effects of substituent bulkiness around a porphyrin core on the photovoltaic properties of porphyrin-sensitized solar cells, long alkoxy groups were introduced at the meso-phenyl group (ZnPBAT-o-C8) and the anchoring group (ZnPBAT-o-C8Cn, n = 4, 8) of an asymmetrically substituted push-pull porphyrin with double electron-donating diarylamino groups and a single electron-withdrawing carboxyphenylethynyl anchoring group. The spectroscopic and electrochemical properties of ZnPBAT-o-C8 and ZnPBAT-o-C8Cn were found to be superior to those of a push-pull porphyrin reference (YD2-o-C8), demonstrating their excellent light-harvesting and redox properties for dye-sensitized solar cells. A power conversion efficiency (η) of the ZnPBAT-o-C8-sensitized solar cell (η = 9.1%) is higher than that of the YD2-o-C8-sensitized solar cell (η = 8.6%) using iodine-based electrolyte due to the enhanced light-harvesting ability of ZnPBAT-o-C8. In contrast, the solar cells based on ZnPBAT-o-C8Cn, possessing the additional alkoxy chains in the anchoring group, revealed the lower η values of 7.3% (n = 4) and 7.0% (n = 8). Although ZnPBAT-o-C8Cn exhibited higher resistance at the TiO2-dye-electrolyte interface by virtue of the extra alkoxy chains, the reduced amount of the porphyrins on TiO2 by excessive addition of coadsorbent chenodeoxycholic acid (CDCA) for mitigating the aggregation on TiO2 resulted in the low η values. Meanwhile, the ZnPBAT-o-C8-sensitized solar cell showed the lower η value of 8.1% than the YD2-o-C8-sensitized solar cell (η = 9.8%) using cobalt-based electrolyte. The smaller η value of the ZnPBAT-o-C8-sensitized solar cell may be attributed to the insufficient blocking effect of the bulky substituents of ZnPBAT-o-C8 under the cobalt-based electrolyte conditions. Overall, the alkoxy chain length and substitution position around the porphyrin core are important factors to affect the cell performance. PMID:27267428

  3. Modular assembly of a photovoltaic solar energy receiver

    DOEpatents

    Graven, Robert M.; Gorski, Anthony J.; Schertz, William W.; Graae, Johan E. A.

    1978-01-01

    There is provided a modular assembly of a solar energy concentrator having a photovoltaic energy receiver with passive cooling. Solar cell means are fixedly coupled to a radiant energy concentrator. Tension means bias a large area heat sink against the cell thereby allowing the cell to expand or contract with respect to the heat sink due to differential heat expansion.

  4. Photovoltaic Experiment Using Light from a Solar Simulator Lamp.

    ERIC Educational Resources Information Center

    Chow, R. H.

    1980-01-01

    A photovoltaic cell experiment utilizing the convenience of a solar simulating type lamp is described. Insight into the solid state aspect of a solar cell is gained by the student in studying the characteristics, and deducing from them cell parameters and efficiency. (Author/CS)

  5. Improved photovoltaic performance of silicon nanowire/organic hybrid solar cells by incorporating silver nanoparticles

    PubMed Central

    2013-01-01

    Silicon nanowire (SiNW) arrays show an excellent light-trapping characteristic and high mobility for carriers. Surface plasmon resonance of silver nanoparticles (AgNPs) can be used to increase light scattering and absorption in solar cells. We fabricated a new kind of SiNW/organic hybrid solar cell by introducing AgNPs. Reflection spectra confirm the improved light scattering of AgNP-decorated SiNW arrays. A double-junction tandem structure was designed to manufacture our hybrid cells. Both short-circuit current and external quantum efficiency measurements show an enhancement in optical absorption of organic layer, especially at lower wavelengths. PMID:23418988

  6. Influence of titania thin film morphology on the photovoltaic action of hybrid titania-P3HT solar cell

    NASA Astrophysics Data System (ADS)

    Her, H.-J.; Baek, W.-H.; Lee, H. H.; Kang, C. J.; Kim, Y.-S.

    2008-03-01

    We report the effects of surface properties of a titania (TiO2) interconnected network structure for photovoltaic applications of organic thin-film solar cell. The electron acceptor layer was obtained by annealing after spin coating of mixture of polyethylene glycol (PEG), Poly(3-hexylthiophene) (P3HT) and Poly(methylmethacrylate) (PMMA) with titania sol-gel solution. The fabrication method was simple and efficient for the increase of titania surface area. The size and height of nanocrystal titania was controlled by spin-coating speed of mixed solution and components of mixed polymer. The bulk-heterojunction solar cells consist of a nanocrystalline titania. In addition, P3HT solar cell showed strong dependence upon surface morphology and the best performance of cell was produced an open circuit voltage of 0.55 V, a short circuit current density of 0.78 mA/cm2, a fill factor of 0.51 and corresponding to a power efficiency of 0.22 % (air mass 1.5).

  7. Interband Cascade Photovoltaic Cells

    SciTech Connect

    Yang, Rui Q.; Santos, Michael B.; Johnson, Matthew B.

    2014-09-24

    In this project, we are performing basic and applied research to systematically investigate our newly proposed interband cascade (IC) photovoltaic (PV) cells [1]. These cells follow from the great success of infrared IC lasers [2-3] that pioneered the use of quantum-engineered IC structures. This quantum-engineered approach will enable PV cells to efficiently convert infrared radiation from the sun or other heat source, to electricity. Such cells will have important applications for more efficient use of solar energy, waste-heat recovery, and power beaming in combination with mid-infrared lasers. The objectives of our investigations are to: achieve extensive understanding of the fundamental aspects of the proposed PV structures, develop the necessary knowledge for making such IC PV cells, and demonstrate prototype working PV cells. This research will focus on IC PV structures and their segments for utilizing infrared radiation with wavelengths from 2 to 5 μm, a range well suited for emission by heat sources (1,000-2,000 K) that are widely available from combustion systems. The long-term goal of this project is to push PV technology to longer wavelengths, allowing for relatively low-temperature thermal sources. Our investigations address material quality, electrical and optical properties, and their interplay for the different regions of an IC PV structure. The tasks involve: design, modeling and optimization of IC PV structures, molecular beam epitaxial growth of PV structures and relevant segments, material characterization, prototype device fabrication and testing. At the end of this program, we expect to generate new cutting-edge knowledge in the design and understanding of quantum-engineered semiconductor structures, and demonstrate the concepts for IC PV devices with high conversion efficiencies.

  8. High-efficiency thin and compact concentrator photovoltaics using micro-solar cells with via-holes sandwiched between thin lens-array and circuit board

    NASA Astrophysics Data System (ADS)

    Itou, Akihiro; Asano, Tetsuya; Inoue, Daijiro; Arase, Hidekazu; Matsushita, Akio; Hayashi, Nobuhiko; Futakuchi, Ryutaro; Inoue, Kazuo; Yamamoto, Masaki; Fujii, Eiji; Nakagawa, Tohru; Anda, Yoshiharu; Ishida, Hidetoshi; Ueda, Tetsuzo; Fidaner, Onur; Wiemer, Michael; Ueda, Daisuke

    2014-01-01

    We have developed a compact concentrator photovoltaic (CPV) module that comprises micro-solar cells with an area of ≈0.6 × 0.6 mm2 sandwiched between a 20-mm-thick lens array and a 1-mm-thick circuit board with no air gap. To establish electrical connections between the circuit board and the micro-solar cells, we developed a micro-solar cell with positive and negative electrodes on the lower face of the cell. In this study, we demonstrated the photovoltaic performance of the micro-solar cell closely approaches that of the standard solar cell measuring ≈5 × 5 mm2 commonly used in conventional CPVs under concentrated illumination. Our study showed that the negative effect on PV performance of perimeter carrier recombination in the micro-solar cell was insignificant under concentrated illumination. Finally, we assembled our micro-solar cells into a CPV module and achieved the module energy conversion efficiency of 34.7% under outdoor solar illumination.

  9. Photovoltaic properties of Cu(In,Ga)Se{sub 2} thin film solar cell fabricated by coevaporation process

    SciTech Connect

    Nishitani, M.; Negami, T.; Ikeda, M.; Kohara, N.; Terauchi, M.; Wada, T.; Hirao, T.

    1994-12-31

    Thin film solar cells based on Cu(In,Ga)Se{sub 2} films were fabricated, and their junction and photovoltaic properties were investigated. Ga in CuInSe{sub 2} thin films formed by so-called bilayer process was incorporated homogeneously. The fabricated cell structure was glass/Mo/Cu(In,Ga)Se{sub 2}/CdS/ZnO/ITO(/MgF{sub 2}). The incorporations of Ga into CuInSe{sub 2} films up to about 20 mol% improved the photovoltaic performance. From the study of photoluminescence, capacitance-voltage and current-voltage characteristics, it was clarified that the incorporation of Ga not only widened the bandgap energy, but also played an important role in the effect which yield hole concentration. The best cell with an AR-coating (MgF{sub 2}) exhibited an efficiency of 15.2%; Jsc = 33.9 mA/cm{sup 2}, Voc = 0.616 V, FF = 0.730. The device performance can be improved by the development of the film with higher hole concentration, keeping the crystalline quality.

  10. Transparent, near-infrared organic photovoltaic solar cells for window and energy-scavenging applications

    SciTech Connect

    Lunt, Richard R; Bulovic, Vladimir

    2011-03-14

    We fabricate near-infrared absorbing organic photovoltaics that are highly transparent to visible light. By optimizing near-infrared optical-interference, we demonstrate power efficiencies of 1.3±0.1% with simultaneous average visible transmission of >65% . Subsequent incorporation of near-infrared distributed-Bragg-reflector mirrors leads to an increase in the efficiency to 1.7±0.1% , approaching the 2.4±0.2% efficiency of the opaque cell, while maintaining high visible-transparency of >55% . Finally, we demonstrate that a series-integrated array of these transparent cells is capable of powering electronic devices under near-ambient lighting. This architecture suggests strategies for high-efficiency power-generating windows and highlights an application uniquely benefiting from excitonic electronics.

  11. Photovoltaics for commercial solar power applications; Proceedings of the Meeting, Cambridge, MA, Sept. 18, 19, 1986

    NASA Astrophysics Data System (ADS)

    Adler, David

    1986-01-01

    Papers are presented on efficient multijunction monolithic cascade solar cells, high efficiency silicon solar cells, point contact silicon cells, and space solar cell research. Also considered are photovoltaic power plants, the reliability of photovoltaic modules, the continuous fabrication of amorphous silicon solar cells on polymer substrates, and the density of states of amorphous silicon. Other topics include breaking the efficiency-stability-production barrier in amorphous photovoltaics, the development of flexible a-SiC/a-Si heterojunction solar cells and stable a-SiC/a-Si tandem cells with blocking barriers, and performance aspects for thin-film-silicon-hydrogen solar cells.

  12. Inverted organic photovoltaic cells.

    PubMed

    Wang, Kai; Liu, Chang; Meng, Tianyu; Yi, Chao; Gong, Xiong

    2016-05-21

    The advance in lifestyle, modern industrialization and future technological revolution are always at high expense of energy consumption. Unfortunately, there exist serious issues such as limited storage, high cost and toxic contamination in conventional fossil fuel energy sources. Instead, solar energy represents a renewable, economic and green alternative in the future energy market. Among the photovoltaic technologies, organic photovoltaics (OPVs) demonstrate a cheap, flexible, clean and easy-processing way to convert solar energy into electricity. However, OPVs with a conventional device structure are still far away from industrialization mainly because of their short lifetime and the energy-intensive deposition of top metal electrode. To address the stability and cost issue simultaneously, an inverted device structure has been introduced into OPVs, bridging laboratory research with practical application. In this review, recent progress in device structures, working mechanisms, functions and advances of each component layer as well their correlations with the efficiency and stability of inverted OPVs are reviewed and illustrated. PMID:27087582

  13. Concepts for thin-film GaAs concentrator cells. [for solar photovoltaic space power systems

    NASA Technical Reports Server (NTRS)

    Spitzer, M. B.; Gale, R. P.; Mcclelland, R.; King, B.; Dingle, J.

    1989-01-01

    The development of advanced GaAs concentrator solar cells, and in particular, the use of CLEFT (cleavage of lateral epitaxial films for transfer) processes for formation of thin-film structures is reported. The use of CLEFT has made possible processing of the back, and cells with back surface grids are discussed. Data on patterned junction development are presented; such junctions are expected to be useful in back surface applications requiring point contacts, grating structures, and interdigitated back contacts. CLEFT concentrator solar cells with grids on the front and back surfaces are reported here; these cells are 4 microns thick and are bonded to glass covers for support. Air mass zero efficiency of 18.8 percent has been obtained for a CLEFT concentrator operating at 18.5 suns.

  14. Correction: Dye adsorption mechanisms in TiO2 films, and their effects on the photodynamic and photovoltaic properties in dye-sensitized solar cells.

    PubMed

    Hwang, Kyung-Jun; Shim, Wang-Geun; Kim, Dajung; An, Jongdeok; Im, Chan; Kim, Youngjin; Kim, Gunwoo; Choi, Chulmin; Kang, Sang Ook; Cho, Dae Won

    2016-02-21

    Correction for 'Dye adsorption mechanisms in TiO2 films, and their effects on the photodynamic and photovoltaic properties in dye-sensitized solar cells' by Kyung-Jun Hwang et al., Phys. Chem. Chem. Phys., 2015, 17, 21974-21981. PMID:26792293

  15. Enhanced photovoltaic performance of perovskite solar cells with mesoporous SiO2 scaffolds

    NASA Astrophysics Data System (ADS)

    Yu, Xiao; Chen, Si; Yan, Kai; Cai, Xin; Hu, Hsienwei; Peng, Ming; Chen, Buxin; Dong, Bin; Gao, Xue; Zou, Dechun

    2016-09-01

    We applied SiO2 nanoparticles as an alternative to mesoporous TiO2 or Al2O3 scaffolds and achieved power conversion efficiency (PCE) of up to 16.2%. Careful characterization of the effects of different scaffolds on device performance reveals that SiO2-based perovskite solar cells show much higher PCE due to the higher Voc and fill factor (FF), and the hysteresis for SiO2-based perovskite solar cell is less severe than for Al2O3-based perovskite solar cell. Time-correlated-single-photoncounting (TCSPC) luminescence decay and external quantum efficiency (EQE) tests provide further insights into the charge transfer behavior and light-harvesting characteristics of the proposed devices. Potential mechanisms of the observed phenomena are also suggested. Taken together, our results demonstrate that SiO2 nanoparticles may potentially replace mesoporous TiO2 or Al2O3 scaffolds in perovskite solar cells to achieve remarkably high PCE.

  16. Photovoltaics: A Solar Technology for Powering Tomorrow.

    ERIC Educational Resources Information Center

    Flavin, Christopher

    1983-01-01

    Photovoltaics, the technology that converts sunlight directly into electricity, may soon be a reliable power source for the world's poor. The one major challenge is cost reduction. Many topics are discussed, including solar powering the Third World, designing the solar building, investing in the sun, and the future of photovoltaics. (NW)

  17. Pilot production of 4 sq cm ITO/InP photovoltaic solar cells

    NASA Technical Reports Server (NTRS)

    Gessert, T. A.; Li, X.; Coutts, T. J.; Tzafaras, N.

    1991-01-01

    Experimental results of a pilot production of 32 4-sq cm indium tin oxide (ITO)InP space solar cells are presented. The discussion includes analysis of the device performance of the best cells produced as well as the performance range of all production cells. The experience gained from the production is discussed, indicating other issues that may be encountered when large-scale productions are initiated. Available data on a 4-sq cm ITO/InP cell that was flown on the UoSAT-5 satellite is reported.

  18. Influence of polar solvents on photovoltaic performance of Monascusred dye-sensitized solar cell

    NASA Astrophysics Data System (ADS)

    Lee, Jae Wook; Kim, Tae Young; Ko, Hyun Seok; Han, Shin; Lee, Suk-Ho; Park, Kyung Hee

    Dye-sensitized solar cells (DSSCs) were assembled using natural dyes extracted from Monascus red pigment as a sensitizer. In this work, we studied the adsorption characteristics for harvesting sunlight and the electrochemical behavior for electron transfer in Monascus red DSSC using different solvents. The effect of polar aprotic and protic solvents including water, ethanol, and dimethylsulfoxide (DMSO) used in the sensitization process was investigated for the improvement in conversion efficiency of a cell. As for the Monascus red dye-sensitized electrode in DMSO solvent, the solar cell yields a short-circuit current density (Jsc) of 1.23 mA/cm2, a photovoltage (Voc) of 0.75 V, and a fill factor of 0.72, corresponding to an energy conversion efficiency (η) of 0.66%.

  19. Fano-induced solar absorption enhancement in thin organic photovoltaic cells

    NASA Astrophysics Data System (ADS)

    Le, Khai Q.; Alù, Andrea

    2014-10-01

    We explore the enhancement mechanisms associated with combined Fano resonances in metasurfaces, demonstrating enhanced absorption efficiency of thin-film organic solar cells over a moderately broad bandwidth of operation. An integrated AM1.5G (air mass 1.5 global solar energy) absorption enhancement of up to 44.6% is obtained, corresponding to an increase in solar absorption at normal incidence from 48% to 69.4%. Fano resonances are induced in arrays of four asymmetric-arranged nanodisks (nanopillars) with small inter-disk gaps, incorporated into an organic thin-film. They are shown to play a dominant role in light-trapping enhancement, mediated by combined localized surface plasmon resonances.

  20. Enhanced photovoltaic performance of ultrathin Si solar cells via semiconductor nanocrystal sensitization: energy transfer vs. optical coupling effects

    NASA Astrophysics Data System (ADS)

    Hoang, Son; Ashraf, Ahsan; Eisaman, Matthew D.; Nykypanchuk, Dmytro; Nam, Chang-Yong

    2016-03-01

    Excitonic energy transfer (ET) offers exciting opportunities for advances in optoelectronic devices such as solar cells. While recent experimental attempts have demonstrated its potential in both organic and inorganic photovoltaics (PVs), what remains to be addressed is quantitative understanding of how different ET modes contribute to PV performance and how ET contribution is differentiated from the classical optical coupling (OC) effects. In this study, we implement an ET scheme using a PV device platform, comprising CdSe/ZnS nanocrystal energy donor and 500 nm-thick ultrathin Si acceptor layers, and present the quantitative mechanistic description of how different ET modes, distinguished from the OC effects, increase the light absorption and PV efficiency. We find that nanocrystal sensitization enhances the short circuit current of ultrathin Si solar cells by up to 35%, of which the efficient ET, primarily driven by a long-range radiative mode, contributes to 38% of the total current enhancement. These results not only confirm the positive impact of ET but also provide a guideline for rationally combining the ET and OC effects for improved light harvesting in PV and other optoelectronic devices.Excitonic energy transfer (ET) offers exciting opportunities for advances in optoelectronic devices such as solar cells. While recent experimental attempts have demonstrated its potential in both organic and inorganic photovoltaics (PVs), what remains to be addressed is quantitative understanding of how different ET modes contribute to PV performance and how ET contribution is differentiated from the classical optical coupling (OC) effects. In this study, we implement an ET scheme using a PV device platform, comprising CdSe/ZnS nanocrystal energy donor and 500 nm-thick ultrathin Si acceptor layers, and present the quantitative mechanistic description of how different ET modes, distinguished from the OC effects, increase the light absorption and PV efficiency. We find that

  1. A versatile chemical conversion synthesis of Cu2S nanotubes and the photovoltaic activities for dye-sensitized solar cell

    PubMed Central

    2014-01-01

    A versatile, low-temperature, and low-cost chemical conversion synthesis has been developed to prepare copper sulfide (Cu2S) nanotubes. The successful chemical conversion from ZnS nanotubes to Cu2S ones profits by the large difference in solubility between ZnS and Cu2S. The morphology, structure, and composition of the yielded products have been examined by field-emission scanning electron microscopy, transmission electron microscopy, and X-ray diffraction measurements. We have further successfully employed the obtained Cu2S nanotubes as counter electrodes in dye-sensitized solar cells. The light-to-electricity conversion results show that the Cu2S nanostructures exhibit high photovoltaic conversion efficiency due to the increased surface area and the good electrocatalytical activity of Cu2S. The present chemical route provides a simple way to synthesize Cu2S nanotubes with a high surface area for nanodevice applications. PMID:25246878

  2. Photovoltaic study of dye sensitized solar cells based on TiO2, ZnO:Al3+ nanoparticles

    NASA Astrophysics Data System (ADS)

    Sánchez Godoy, H. E.; Rodríguez-Rojas, R. A.; Castañeda-Contreras, J.; Marañón-Ruiz, V. F.; Pérez-Ladrón de Guevara, H.; López-Luke, T.; De la Rosa-Cruz

    2015-10-01

    A technique to fabricate dye (rhodamine B) sensitized solar cells based on Titanium Oxide (TiO2) and Zinc Oxide (ZnO) nanoparticles are reported. The TiO2 was synthesized using the sol-gel method and the ZnO was synthesized by hydrolysis method to obtain nanoparticles of ~ 5 nm and 150 nm respectively. ZnO was doped with Al3+ in order to enhance the photovoltaic efficiency to promote the electrons mobility. The photovoltaic conversion characterization of films of TiO2, ZnO and ZnO:Al3+ nanoparticles is also reported. The generated photocurrent was measured by two methods; one of those uses a three electrode electrochemical cell and the other use an electronic array where the cells were exposed to UV lamp and the sun light. The role of the TiO2, ZnO and Al3+ doped ZnO nanoparticles is discussed to obtain a better efficiency in the generation of photocurrent (PC). The results exhibited by the electrochemical cell method, efficiencies of 0.55 (PC=187 μA/cm2) and 0.22 (PC=149 μA/cm2) for TiO2 and undoped ZnO respectively. However, when ZnO is doped with Al3+ at the higher concentration the efficiency was 0.44. While using the electronic array the results exhibited efficiencies of 0.31 (PC=45 μA/cm2) and 0.09 (PC=16 μA/cm2) for TiO2 and undoped ZnO respectively. However, when ZnO is doped with Al3+ at the higher concentration the efficiency was 0.44 and 0.48 for electrochemical cell and electronic array respectively. This shows that Al3+ enhances the photogenerated charge carriers increasing the mobility of electrons.

  3. Photovoltaic performance of thin-film CdS-Cu2S solar cells with electroformed junctions

    NASA Astrophysics Data System (ADS)

    Rastogi, A. C.

    1985-06-01

    Irreproducibility and low conversion efficiency of CdS-Cu2S solar cells fabricated by the chemiplating process are found to be the result of variations in the surface morphology of the textured CdS surface. To counter such problems, a new technique of barrier formation using direct-current (DC) field-assisted control over the reacting ionic species is described. Photovoltaic data on solar cells fabricated in this way display an overall improvement owing to the prevention of deep-intruded Cu(2-x)S growth along the CdS grain boundaries and a closer approximation to stoichiometry. In addition, with the use of the DC potential as a first-order variable these improved characteristics of the junctions have been found to be less sensitive to the Cu(2-x)S deposition variables, thus improving general reproducibility. Data on the cells made by the new technique obtained from spectral response, sheet resistivity, and accelerated life tests are presented.

  4. Enhanced photovoltaic properties and long-term stability in plasmonic dye-sensitized solar cells via noncorrosive redox mediator.

    PubMed

    Jung, Heesuk; Koo, Bonkee; Kim, Jae-Yup; Kim, Taehee; Son, Hae Jung; Kim, BongSoo; Kim, Jin Young; Lee, Doh-Kwon; Kim, Honggon; Cho, Jinhan; Ko, Min Jae

    2014-11-12

    We demonstrate the localized surface plasmon resonance (LSPR) effect, which can enhance the photovoltaic properties of dye-sensitized solar cells (DSSCs), and the long-term stability of size-controlled plasmonic structures using a noncorrosive redox mediator. Gold nanoparticles (Au NPs) were synthesized with a phase transfer method based on ligand exchange. This synthetic method is advantageous because the uniformly sized Au NPs, can be mass produced and easily applied to DSSC photoanodes. The plasmonic DSSCs showed an 11% improvement of power conversion efficiency due to the incorporation of 0.07 wt % Au NPs, compared to the reference DSSCs without Au NPs. The improved efficiency was primarily due to the enhanced photocurrent generation by LSPR effect. With the cobalt redox mediator, the long-term stability of the plasmonic structures also significantly increased. The plasmonic DSSCs with cobalt(II/III) tris(2,2'-bipyridine) ([Co(bpy)3](2+/3+)) redox mediator maintained the LSPR effect with stable photovoltaic performance for 1000 h. This is, to our knowledge, the first demonstration of the long-term stability of plasmonic nanostructures in plasmonic DSSCs based on liquid electrolytes. As a result, the enhanced long-term stability of plasmonic NPs via a noncorrosive redox mediator will increase the feasibility of plasmonic DSSCs. PMID:25296336

  5. Flexible, rollable photovoltaic cell module

    SciTech Connect

    Cull, C.R.; Hartman, R.A.; Koch, P.E.

    1986-03-04

    A photovoltaic module is described consisting of: busbar means; individual photovoltaic cell strips, each cell strip having an electrically conductive substrate layer, a semiconductor body deposited on the substrate layer, and a transparent electrically conductive layer deposited on the semiconductor body, the transparent electrically conductive layer being selectively sectioned to define electrically distinct photovoltaic cells carried by the cell strip; grid means deposited on the transparent electrically conductive layer of each of the photovoltaic cell; continuous electrically conductive filament means alternately and repetitively connected, at contact points, to the electrically conductive substrate layer of one photovoltaic cell strip and to the grid means of another photovoltaic cell strip; wherein the filament means is connected medially of the lateral edges of the respective cell strips; and means for connecting the transparent electrically conductive layer of one photovoltaic cell strip to the busbar means.

  6. Thin film photovoltaic cell

    DOEpatents

    Meakin, John D.; Bragagnolo, Julio

    1982-01-01

    A thin film photovoltaic cell having a transparent electrical contact and an opaque electrical contact with a pair of semiconductors therebetween includes utilizing one of the electrical contacts as a substrate and wherein the inner surface thereof is modified by microroughening while being macro-planar.

  7. Combination solar photovoltaic heat engine energy converter

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.

    1987-01-01

    A combination solar photovoltaic heat engine converter is proposed. Such a system is suitable for either terrestrial or space power applications. The combination system has a higher efficiency than either the photovoltaic array or the heat engine alone can attain. Advantages in concentrator and radiator area and receiver mass of the photovoltaic heat engine system over a heat-engine-only system are estimated. A mass and area comparison between the proposed space station organic Rankine power system and a combination PV-heat engine system is made. The critical problem for the proposed converter is the necessity for high temperature photovoltaic array operation. Estimates of the required photovoltaic temperature are presented.

  8. Amorphous Carbon Deposited by a Novel Aerosol-Assisted Chemical Vapor Deposition for Photovoltaic Solar Cells

    NASA Astrophysics Data System (ADS)

    Ahmad, Nurfadzilah; Kamaruzzaman, Dayana; Rusop, Mohamad

    2012-06-01

    Amorphous carbon (a-C) solar cells were successfully prepared using a novel and self-designed aerosol-assisted chemical vapor deposition (AACVD) method using camphor oil as a precursor. The fabricated solar cell with the configuration of Au/p-C/n-Si/Au achieved an efficiency of 0.008% with a fill factor of 0.15 for the device deposited at 0.5 h. The current-voltage (I-V) graph emphasized on the linear graph (ohmic) for the a-C thin films, whereas for the p-n device structure, a rectifying curve was obtained. The rectifying curves signify the heterojunction between the p-type a-C film and the n-Si substrate and designate the generation of electron-hole pair of the samples under illumination. Photoresponse characteristics of the deposited a-C was highlighted when being illuminated (AM 1.5 illumination: 100 mW/cm2, 25 °C). Transmittance spectrum exhibit a large transmittance value (>85%) and absorption coefficient value of 103-104 cm-1 at the visible range of 390 to 790 nm. The atomization of a liquid precursor solution into fine sub-micrometre-sized aerosol droplets in AACVD induced the smooth surface of a-C films. To the best of our knowledge, fabrication of a-C solar cell using this AACVD method has not yet been reported.

  9. Hybrid Microgrid Model based on Solar Photovoltaics with Batteries and Fuel Cells system for intermittent applications

    NASA Astrophysics Data System (ADS)

    Patterson, Maxx

    Microgrids are a subset of the modern power structure; using distributed generation (DG) to supply power to communities rather than vast regions. The reduced scale mitigates loss allowing the power produced to do more with better control, giving greater security, reliability, and design flexibility. This paper explores the performance and cost viability of a hybrid grid-tied microgrid that utilizes Photovoltaic (PV), batteries, and fuel cell (FC) technology. The concept proposes that each community home is equipped with more PV than is required for normal operation. As the homes are part of a microgrid, excess or unused energy from one home is collected for use elsewhere within the microgrid footprint. The surplus power that would have been discarded becomes a community asset, and is used to run intermittent services. In this paper, the modeled community does not have parking adjacent to each home allowing for the installment of a privately owned slower Level 2 charger, making EV ownership option untenable. A solution is to provide a Level 3 DC Quick Charger (DCQC) as the intermittent service. The addition of batteries and Fuel Cells are meant to increase load leveling, reliability, and instill limited island capability.

  10. Measuring The Contact Resistances Of Photovoltaic Cells

    NASA Technical Reports Server (NTRS)

    Burger, D. R.

    1985-01-01

    Simple method devised to measure contact resistances of photovoltaic solar cells. Method uses readily available equipment and applicable at any time during life of cell. Enables evaluation of cell contact resistance, contact-end resistance, contact resistivity, sheet resistivity, and sheet resistivity under contact.

  11. Proceedings of the First ERDA Semiannual Solar Photovoltaic Conversion Program Conference

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Organization, basic research and applied technology for the Solar Photovoltaic Conversion Program are outlined. The program aims to provide a technology base for low cost thin film solar cells and solar arrays.

  12. Enhanced photovoltaic performance of ultrathin Si solar cells via semiconductor nanocrystal sensitization: energy transfer vs. optical coupling effects.

    PubMed

    Hoang, Son; Ashraf, Ahsan; Eisaman, Matthew D; Nykypanchuk, Dmytro; Nam, Chang-Yong

    2016-03-10

    Excitonic energy transfer (ET) offers exciting opportunities for advances in optoelectronic devices such as solar cells. While recent experimental attempts have demonstrated its potential in both organic and inorganic photovoltaics (PVs), what remains to be addressed is quantitative understanding of how different ET modes contribute to PV performance and how ET contribution is differentiated from the classical optical coupling (OC) effects. In this study, we implement an ET scheme using a PV device platform, comprising CdSe/ZnS nanocrystal energy donor and 500 nm-thick ultrathin Si acceptor layers, and present the quantitative mechanistic description of how different ET modes, distinguished from the OC effects, increase the light absorption and PV efficiency. We find that nanocrystal sensitization enhances the short circuit current of ultrathin Si solar cells by up to 35%, of which the efficient ET, primarily driven by a long-range radiative mode, contributes to 38% of the total current enhancement. These results not only confirm the positive impact of ET but also provide a guideline for rationally combining the ET and OC effects for improved light harvesting in PV and other optoelectronic devices. PMID:26677967

  13. Diamond-Like Carbon Coatings as Encapsulants for Photovoltaic Solar Cells

    SciTech Connect

    Pern, F. J.; Panosyan, Zh.; Gippius, A. A.; Kontsevoy, J. A.; Touryan, K.; Voskanyan, S.; Yengibaryan, Y.

    2005-02-01

    High-quality single-layer and bilayer diamond-like carbon (DLC) thin films are fabricated by two technologies, namely, ion-assisted plasma-enhanced deposition (IAPED) and electron cyclotron resonance (ECR) deposition. Deposition on various substrates, such as sapphires and solar cells, has been performed at low substrate temperatures (50 {approx} 80 C). The two deposition technologies allow good control over the growth conditions to produce DLC films with desired optical properties, thickness, and energy bandgap. The bilayer-structured DLC can be fabricated by using IAPED for the bottom layer followed by ECR for the top layer, or just by IAPED for both layers with different compositions. The DLC films have shown good spatial uniformity, density, microhardness, and adhesion strength. They exhibit excellent stability against attack by strong acids, prolonged damp-heat exposure at 85 C and 85% relative humidity, mechanical scratch, ultrasonication, and irradiation by ultraviolet (UV), protons, and electrons. When deposited on crystalline Si and GaAs solar cells in single-layer and/or bilayer structure, the DLC films not only serve as antireflection coating and protective encapsulant, but also improve the cell efficiencies.

  14. Enhanced photovoltaic performance of a quantum dot-sensitized solar cell using a Nb-doped TiO2 electrode

    NASA Astrophysics Data System (ADS)

    Jiang, Lei; You, Ting; Deng, Wei-Qiao

    2013-10-01

    In this work Nb-doped anatase TiO2 nanocrystals are used as the photoanode of quantum-dot-sensitized solar cells. A solar cell with CdS/CdSe quantum dots co-sensitized 2.5 mol% Nb-doped anatase TiO2 nanocrystals can achieve a photovoltaic conversion efficiency of 3.3%, which is almost twice as high as the 1.7% obtained by a cell based on undoped TiO2 nanocrystals. The incident photon-to-current conversion efficiency can reach as high as 91%, which is a record for all quantum-dot-sensitized solar cells. Detailed analysis shows that such an enhancement is due to improved lifetime and diffusion length of electrons in the solar cell.

  15. Enhanced photovoltaic performance of a quantum dot-sensitized solar cell using a Nb-doped TiO2 electrode.

    PubMed

    Jiang, Lei; You, Ting; Deng, Wei-Qiao

    2013-10-18

    In this work Nb-doped anatase TiO2 nanocrystals are used as the photoanode of quantum-dot-sensitized solar cells. A solar cell with CdS/CdSe quantum dots co-sensitized 2.5 mol% Nb-doped anatase TiO2 nanocrystals can achieve a photovoltaic conversion efficiency of 3.3%, which is almost twice as high as the 1.7% obtained by a cell based on undoped TiO2 nanocrystals. The incident photon-to-current conversion efficiency can reach as high as 91%, which is a record for all quantum-dot-sensitized solar cells. Detailed analysis shows that such an enhancement is due to improved lifetime and diffusion length of electrons in the solar cell. PMID:24045808

  16. Photovoltaic performance of hybrid ITO/PEDOT:PSS/n-SnS/Al solar cell structure

    NASA Astrophysics Data System (ADS)

    Jain, Priyal; Arun, P.

    2016-07-01

    The present paper discusses the performance of ITO/PEDOT:PSS/n-SnS/Al structured solar cells fabricated by thermal evaporation. The performance characterizing parameters such as the open circuit voltage, short circuit current density, series resistance, parallel resistance, ideality factor and the overall efficiency were found to be dependent on the SnS grain size in the nano-meter regime and incident light intensity. The experimental work directly reconfirms the theoretical results and ideas raised in the literature by early researchers.

  17. The status of lightweight photovoltaic space array technology based on amorphous silicon solar cells

    NASA Technical Reports Server (NTRS)

    Hanak, Joseph J.; Kaschmitter, Jim

    1991-01-01

    Ultralight, flexible photovoltaic (PV) array of amorphous silicon (a-Si) was identified as a potential low cost power source for small satellites. A survey was conducted of the status of the a-Si PV array technology with respect to present and future performance, availability, cost, and risks. For existing, experimental array blankets made of commercial cell material, utilizing metal foil substrates, the Beginning of Life (BOL) performance at Air Mass Zero (AM0) and 35 C includes total power up to 200 W, power per area of 64 W/sq m and power per weight of 258 W/kg. Doubling of power per weight occurs when polyimide substrates are used. Estimated End of Life (EOL) power output after 10 years in a nominal low earth orbit would be 80 pct. of BOL, the degradation being due to largely light induced effects (-10 to -15 pct.) and in part (-5 pct.) to space radiation. Predictions for the year 1995 for flexible PV arrays, made on the basis of published results for rigid a-Si modules, indicate EOL power output per area and per weight of 105 W/sq m and 400 W/kg, respectively, while predictions for the late 1990s based on existing U.S. national PV program goals indicate EOL values of 157 W/sq m and 600 W/kg. Cost estimates by vendors for 200 W ultralight arrays in volume of over 1000 units range from $100/watt to $125/watt. Identified risks include the lack of flexible, space compatible encapsulant, the lack of space qualification effort, recent partial or full acquisitions of US manufacturers of a-Si cells by foreign firms, and the absence of a national commitment for a long range development program toward developing of this important power source for space.

  18. Effect of thermal annealing in vacuum on the photovoltaic properties of electrodeposited Cu2O-absorber solar cell

    NASA Astrophysics Data System (ADS)

    Dimopoulos, T.; Peić, A.; Abermann, S.; Postl, M.; List-Kratochvil, E. J. W.; Resel, R.

    2014-07-01

    Heterojunction solar cells were fabricated by electrochemical deposition of p-type, cuprous oxide (Cu2O) absorber on sputtered, n-type ZnO layer. X-ray diffraction measurements revealed that the as-deposited absorber consists mainly of Cu2O, but appreciable amounts of metallic Cu and cupric oxide (CuO) are also present. These undesired oxidation states are incorporated during the deposition process and have a detrimental effect on the photovoltaic properties of the cells. The open circuit voltage (VOC), short circuit current density (jSC), fill factor (FF) and power conversion efficiency (η) of the as-deposited cells are 0.37 V, 3.71 mA/cm2, 35.7% and 0.49%, respectively, under AM1.5G illumination. We show that by thermal annealing in vacuum, at temperatures up to 300 °C, compositional purity of the Cu2O absorber could be obtained. A general improvement of the heterojunction and bulk materials quality is observed, reflected upon the smallest influence of the shunt and series resistance on the transport properties of the cells in dark and under illumination. Independent of the annealing temperature, transport is dominated by the space-charge layer generation-recombination current. After annealing at 300 °C the solar cell parameters could be significantly improved to the values of: VOC = 0.505 V, jSC = 4.67 mA/cm2, FF = 47.1% and η = 1.12%.

  19. Efficient mineralization of the antibiotic trimethoprim by solar assisted photoelectro-Fenton process driven by a photovoltaic cell.

    PubMed

    Zhang, Yanyu; Wang, Aimin; Tian, Xiujun; Wen, Zhenjun; Lv, Hanjiao; Li, Desheng; Li, Jiuyi

    2016-11-15

    In this study, a novel self-sustainable solar assisted photoelectro-Fenton (SPEF) system driven by a solar photovoltaic cell was developed for the efficient mineralization of antibiotic trimethoprim (TMP) in water. A comparative degradation of 200mgL(-1) TMP by RuO2/Ti anodic oxidation (AO), anodic oxidation with H2O2 electrogeneration (AO-H2O2), electro-Fenton (EF) and SPEF was investigated. SPEF was proved to exhibit the highest oxidation power, i.e., more than 80% TOC was removed after 360min SPEF treatment of 200mgL(-1) of TMP under optimal conditions at pH 3.0, 1.0mM Fe(2+) and 18mAcm(-2). Influences of current density, pH, initial Fe(2+) and initial TMP concentration on SPEF process were also studied. Ten aromatic intermediates generated from hydroxylation, carbonylation and demethylation reactions were identified using UPLC-QTOF-MS/MS system during the SPEF treatment, together with three carboxylic acids (oxamic, oxalic and formic acids) and two inorganic ions (NH4(+) and NO3(-)) measured. Therefore, a reasonable pathway of TMP degradation in SPEF process was proposed. PMID:27434735

  20. Absorption spectra and photovoltaic characterization of chlorophyllins as sensitizers for dye-sensitized solar cells.

    PubMed

    Calogero, Giuseppe; Citro, Ilaria; Crupi, Cristina; Di Marco, Gaetano

    2014-11-11

    Dye-sensitized solar cells (DSSCs) based on Chlorine-e6 (Chl-e6), a Chlorophyll a derivative, and Chl-e6 containing Cu, have been investigated by carrying out incident photon to current efficiency (IPCE) and current-voltage (I-V) measurements. The effect of the metallic ion and the influence of the solvent polarity on the dye aggregation and their absorption bands have been analysed by performing electronic absorption measurements. The dependence of the photoelectrochemical parameters of these DSSCs on the electrolyte by the addition of pyrimidine and/or pyrrole has been discussed in details. For the first time I-V curves for a DSSC based on copper Chl-e6 dye have been shown and compared with Zn based chlorophyllin. Furthermore, the performance of a Cu-Chl-e6 based DSSC has been deeply improved by a progressive optimization of the TiO2 multilayer photoanode overcoming the best data reported in literature so far for this dye. It's worth to emphasize that, the analysis reported in this paper supplies very useful information which paves the way to further detailed studies turned to the employment of natural pigments as sensitizers for solar cells. PMID:24892526

  1. Decolorizing textile wastewater with Fenton's reagent electrogenerated with a solar photovoltaic cell.

    PubMed

    Figueroa, Sandra; Vázquez, Leticia; Alvarez-Gallegos, A

    2009-02-01

    In this work it is demonstrated that Fenton's reagent can be electroproduced with abundant and cheap feedstock: oxygen saturated wastewater and solar energy. Experiments were carried out in a divided electrochemical flow cell using two electrodes: a three dimensional reticulated vitreous carbon cathode and stainless steel anode. Fenton's reagent is produced by oxygen reduction on the cathode in the presence of 1mM Fe(2+). The influence of electrolyte nature and its concentration and potential difference on the current efficiency, as well as the rate of Fenton's reagent electroproduction is discussed and it is concluded that over this extended range of conditions the current efficiency, for Fenton's reagent production, fell within the range 50-70%. It is possible to electroproduce a stoichiometric amount of Fenton reagent for the oxidation of 0.061mM Reactive Black 5 (in tap water+0.05M Na(2)SO(4), approximately pH 2.8). Similar results were obtained for solutions containing 0.1mM Acid Green 25. Some practical applications in the field of water treatment are included. The energy required for drive electrochemical reaction is supplied to the flow cell by means of a commercial solar panel. PMID:18977506

  2. Enhanced charge transport and photovoltaic performance induced by incorporating rare-earth phosphor into organic-inorganic hybrid solar cells.

    PubMed

    Chen, Zihan; Li, Qinghua; Chen, Chuyang; Du, Jiaxing; Tong, Jifeng; Jin, Xiao; Li, Yue; Yuan, Yongbiao; Qin, Yuancheng; Wei, Taihuei; Sun, Weifu

    2014-11-28

    In this work, dysprosium ion decorated yttrium oxide (Dy(3+):Y2O3) nanocrystal phosphors were incorporated into TiO2 acceptor thin film in a bid to enhance the light harvest, charge separation and transfer in the hybrid solar cells. The results show that the energy level offset between the donor (P3HT) and the acceptor (Dy(3+):Y2O3-TiO2) has been narrowed down, thus leading to the enhanced electron and hole transports, and also photovoltaic performances as compared to pure TiO2 without incorporating Dy(3+):Y2O3. By applying femtosecond transient optical spectroscopy, after the incorporation of dopant Dy(3+):Y2O3 into TiO2 at 6 wt%, both the hot electron and hole transfer lifetimes have been shortened, that is, from 30.2 ps and 6.94 ns to 25.1 ps and 1.26 ns, respectively, and an enhanced efficiency approaching 3% was achieved as compared to 2.0% without doping, indicating that the energetic charges are captured more efficiently benefitting a higher power conversion efficiency. Moreover, these results reveal that both the conduction band (CB) and valence band (VB) edges of the acceptor were elevated by 0.57 and 0.32 eV, respectively, after incorporating 6 wt% Dy(3+):Y2O3. This work demonstrates that distinct energy level alignment engineered by Dy(3+):Y2O3 phosphor has an important role in pursuing efficient future solar cells and underscores the promising potential of rare-earth phosphor in solar applications. PMID:25307965

  3. Solar photovoltaics - An aerospace technology

    NASA Technical Reports Server (NTRS)

    Goldsmith, J. V.

    1977-01-01

    Specific problems affecting the development of low-cost silicon solar array power sources are discussed, taking into account the potential of realizing less than $0.50/per peak watt of silicon solar array technology. A utilization of less expensive processes for the manufacture of pure silicon and more economical procedures of silicon crystal and wafer production appear desirable. Attention is given to a sheet growth process example and a concept of pulsed processing for automated cell production.

  4. Grid-Optimization Program for Photovoltaic Cells

    NASA Technical Reports Server (NTRS)

    Daniel, R. E.; Lee, T. S.

    1986-01-01

    CELLOPT program developed to assist in designing grid pattern of current-conducting material on photovoltaic cell. Analyzes parasitic resistance losses and shadow loss associated with metallized grid pattern on both round and rectangular solar cells. Though performs sensitivity studies, used primarily to optimize grid design in terms of bus bar and grid lines by minimizing power loss. CELLOPT written in APL.

  5. Photovoltaic cell array

    NASA Technical Reports Server (NTRS)

    Eliason, J. T. (Inventor)

    1976-01-01

    A photovoltaic cell array consisting of parallel columns of silicon filaments is described. Each fiber is doped to produce an inner region of one polarity type and an outer region of an opposite polarity type to thereby form a continuous radial semi conductor junction. Spaced rows of electrical contacts alternately connect to the inner and outer regions to provide a plurality of electrical outputs which may be combined in parallel or in series.

  6. The development and utilization of solar photovoltaic cells: An assessment of the potential for a new energy technology

    NASA Technical Reports Server (NTRS)

    Cyr, K. J.

    1981-01-01

    The Government set the goal of accelerating the adaptation of photovoltaics by reducing system costs to a competitive level and overcoming the technical, institutional, legal, environmental, and social barriers impeding the diffusion of photovoltaic technology. The technology of silicon solar arrays was examined and the status of development efforts are reviewed. The political, legal, economic, social, and environmental issues are discussed, and several methods for selecting development projects are described. A number of market forecasting techniques, including time trend, judgemental, and econometric methods, were reviewed, and the results of these models are presented.

  7. Silicon Solar Cell Turns 50

    SciTech Connect

    Perlin, J.

    2004-08-01

    This short brochure describes a milestone in solar (or photovoltaic, PV) research-namely, the 50th anniversary of the invention of the first viable silicon solar cell by three researchers at Bell Laboratories.

  8. Ordered defect compounds in CuInSe{sub 2} for photovoltaic solar cell application

    SciTech Connect

    Sato, K.; Katayama-Yoshida, H.

    2014-02-21

    Due to the complete compensation, defect complex (2V{sub Cu}+In{sub Cu}), namely two Cu vacancies and In located at Cu site, is stable in CuInSe{sub 2} (CIS). It is known that the series of ordered defect compounds (ODC) are constracted by ordering the defect complex. Based on the total energy calcalation by using the Korringa-Kohn-Rostoker coherent potential approxiamtion (KKR-CPA) method, we discuss phase separation of the CIS with the defect complexes into ODC and CIS. Since the band alignment between ODC and CIS is calculated to be type 2, effective electron-hole separation at the interface between ODC and CIS can be expected. This causes the enhancement of conversion efficiency of CIS-based solar cell materials.

  9. Photocurrent of Photovoltaic Cells

    NASA Astrophysics Data System (ADS)

    Peeler, Seth; McIntyre, Max; Cossel, Raquel; Bowser, Chris; Tzolov, Marian

    Photovoltaic cells can be used to harness clean, renewable energy from light. Examined in this project were photovoltaic cells based on a bulk heterojunction between PCPDTBT and PCBM sandwiched between an ITO anode and an Al cathode. Current-voltage characteristics and impedance spectra for multiple photovoltaic devices were taken under varying DC electrical bias and different level of illumination. This data was interpreted in terms of an equivalent circuit with linear elements, e.g. capacitance, series resistance, and parallel resistance. A physical interpretation of each circuit element will be presented. The spectral response of the devices was characterized by optical transmission and photocurrent spectroscopy using a spectrometer in the spectral range from 300 to 900 nm. The DC measurements confirmed that the devices are electrically rectifying. The AC measurements allowed modeling of the devices as a dielectric between two electrodes with injection current passing through it. The characteristic peaks for both PCBDTBT and PCBM are clearly visible in both the photocurrent and transmission data. The good correlation between the photocurrent and transmission data indicates photocurrent generation due to absorption in both materials constituting the heterojunction.

  10. Study of enhanced photovoltaic behavior in InGaN-based solar cells by using SiNx insertion layer: Influence of dislocations

    NASA Astrophysics Data System (ADS)

    Lee, Seunga; Honda, Yoshio; Amano, Hiroshi; Jang, Jongjin; Nam, Okhyun

    2016-03-01

    Using a SiNx insertion layer to reduce dislocations, enhanced photovoltaic properties could be obtained in p-i-n InGaN/GaN heterojunction solar cell. To investigate the influence of the dislocations on the photovoltaic behaviors, a sample grown without SiNx insertion layer was identically prepared for comparison. From optical properties measurements, the reduction in the number of non-radiative centers and a stronger In localization effect was shown in the sample with SiNx insertion layer. However, the quantum confined stark effect was almost negligible in both the samples. Electrical properties measurement showed reduced saturation current and increased shunt resistance in the sample with SiNx insertion layer due to the reduced dislocation density. By comparing these results and using a numerical model, the influence of the dislocation density on the different photovoltaic properties such as open-circuit voltage and fill factor has been confirmed.

  11. Photoinduced Interfacial Electron Injection Dynamics in Dye-Sensitized Solar Cells under Photovoltaic Operating Conditions.

    PubMed

    Teuscher, Joël; Décoppet, Jean-David; Punzi, Angela; Zakeeruddin, Shaik M; Moser, Jacques-E; Grätzel, Michael

    2012-12-20

    We report a pump-probe spectroscopy study of electron injection rates in dye-sensitized solar cell (DSSC) devices. We examine the case of working devices employing an N719 ruthenium sensitizer and an iodide electrolyte. Electron injection is found to occur mainly on a sub-100 fs time scale, followed by a slower component with a lifetime of 26.9 ps, in accordance with previous reports on model samples. The amplitude of this latter component varies with electrolyte composition from 25 to 9%. The appearance of slower components in the electron injection dynamics may be attributed to an aggregated or weakly bound state of the surface-adsorbed N719 sensitizer. Further measurements are reported varying the cell light bias and load conditions, revealing no influence on electron injection dynamics. No other electron injection event is found to occur up to 1 ns. These results show no evidence for a slowdown of electron injection under working conditions compared to model systems for the electrolytes examined in this study. PMID:26291112

  12. Solar Photovoltaics Technology: The Revolution Begins . . .

    NASA Astrophysics Data System (ADS)

    Kazmerski, Lawrence

    2009-11-01

    The prospects of current and coming solar-photovoltaic (PV) technologies are envisioned, arguing this solar-electricity source is at a tipping point in the complex worldwide energy outlook. The emphasis of this presentation is on R&D advances (cell, materials, and module options), with indications of the limitations and strengths of crystalline (Si and GaAs) and thin-film (a-Si:H, Si, Cu(In,Ga)(Se,S)2, CdTe). The contributions and technological pathways for now and near-term technologies (silicon, III-Vs, and thin films) and status and forecasts for next- generation PV (organics, nanotechnologies, non-conventional junction approaches) are evaluated. Recent advances in concentrators with efficiencies headed toward 50%, new directions for thin films (20% and beyond), and materials/device technology issues are discussed in terms of technology progress. Insights into technical and other investments needed to tip photovoltaics to its next level of contribution as a significant clean-energy partner in the world energy portfolio. The need for R&D accelerating the now and imminent (evolutionary) technologies balanced with work in mid-term (disruptive) approaches is highlighted. Moreover, technology progress and ownership for next generation solar PV mandates a balanced investment in research on longer-term (the revolution needs revolutionary approaches to sustain itself) technologies (quantum dots, multi-multijunctions, intermediate-band concepts, nanotubes, bio-inspired, thermophotonics, solar hydrogen. . . ) having high-risk, but extremely high performance and cost returns for our next generations of energy consumers. Issues relating to manufacturing are explored-especially with the requirements for the next-generation technologies. This presentation provides insights into how this technology has developed-and where the R&D investments should be made and we can expect to be by this mid-21st century.

  13. Solar photovoltaics for development applications

    SciTech Connect

    Shepperd, L.W.; Richards, E.H.

    1993-08-01

    This document introduces photovoltaic technology to individuals and groups specializing in development activities. Examples of actual installations illustrate the many services supplied by photovoltaic systems in development applications, including water pumping, lighting, health care, refrigeration, communications, and a variety of productive uses. The various aspects of the technology are explored to help potential users evaluate whether photovoltaics can assist them in achieving their organizational goals. Basic system design, financing techniques, and the importance of infrastructure are included, along with additional sources of information and major US photovoltaic system suppliers.

  14. Enhanced photovoltaic properties of dye-sensitized solar cell based on ultrathin 2D TiO2 nanostructures

    NASA Astrophysics Data System (ADS)

    Zhang, Putao; Hu, Zhiqiang; Wang, Yan; Qin, Yiying; Sun, Xiao Wei; Li, Wenqin; Wang, Jinmin

    2016-04-01

    Ultrathin two-dimensional (2D) TiO2 nanostructures with a thickness of ∼5 nm and a specific surface area of 257.3 m2 g-1 were synthesized by a hydrothermal process. The 2D TiO2 nanostructures and P25 nanoparticles were introduced as scattering layer and underlayer to construct a bi-layer photoanode in a dye-sensitized solar cell (DSSC). The as-prepared DSSC exhibits an enhanced power conversion efficiency (5.14%), which is 23.9% higher than that of pure P25 DSSC (4.15%). Electrochemical impedance spectroscopy (EIS) indicates that DSSC based on P25-2D TiO2 nanostructures shows a longer life time and a larger recombination resistance. The enhanced photovoltaic properties are attributed to the excellent light scattering capability and high capacity for dye adsorption of 2D TiO2 nanostructures, which makes them a promising candidate as an efficient scattering layer in high-performance DSSCs.

  15. Low-cost, high-efficiency organic/inorganic hetero-junction hybrid solar cells for next generation photovoltaic device

    NASA Astrophysics Data System (ADS)

    Pudasaini, P. R.; Ayon, A. A.

    2013-12-01

    Organic/inorganic hybrid structures are considered innovative alternatives for the next generation of low-cost photovoltaic devices because they combine advantages of the purely organic and inorganic versions. Here, we report an efficient hybrid solar cell based on sub-wavelength silicon nanotexturization in combination with the spin-coating of poly (3,4-ethylene-dioxythiophene):polystyrenesulfonate (PEDOT:PSS). The described devices were analyzed by collecting current-voltage and capacitance-voltage measurements in order to explore the organic/inorganic heterojunction properties. ALD deposited ultrathin aluminium oxide was used as a junction passivation layer between the nanotextured silicon surface and the organic polymer. The measured interface defect density of the device was observed to decrease with the inclusion of an ultrathin Al2O3 passivation layer leading to an improved electrical performance. This effect is thought to be ascribed to the suppression of charge recombination at the organic/inorganic interface. A maximum power conversion efficiency in excess of 10% has been achieved for the optimized geometry of the device, in spite of lacking an antireflection layer or back surface field enhancement schemes.

  16. Enhanced photovoltaic properties in dye sensitized solar cells by surface treatment of SnO2 photoanodes

    NASA Astrophysics Data System (ADS)

    Basu, Kaustubh; Benetti, Daniele; Zhao, Haiguang; Jin, Lei; Vetrone, Fiorenzo; Vomiero, Alberto; Rosei, Federico

    2016-03-01

    We report the fabrication and testing of dye sensitized solar cells (DSSC) based on tin oxide (SnO2) particles of average size ~20 nm. Fluorine-doped tin oxide (FTO) conducting glass substrates were treated with TiOx or TiCl4 precursor solutions to create a blocking layer before tape casting the SnO2 mesoporous anode. In addition, SnO2 photoelectrodes were treated with the same precursor solutions to deposit a TiO2 passivating layer covering the SnO2 particles. We found that the modification enhances the short circuit current, open-circuit voltage and fill factor, leading to nearly 2-fold increase in power conversion efficiency, from 1.48% without any treatment, to 2.85% achieved with TiCl4 treatment. The superior photovoltaic performance of the DSSCs assembled with modified photoanode is attributed to enhanced electron lifetime and suppression of electron recombination to the electrolyte, as confirmed by electrochemical impedance spectroscopy (EIS) carried out under dark condition. These results indicate that modification of the FTO and SnO2 anode by titania can play a major role in maximizing the photo conversion efficiency.

  17. Enhanced photovoltaic properties in dye sensitized solar cells by surface treatment of SnO2 photoanodes.

    PubMed

    Basu, Kaustubh; Benetti, Daniele; Zhao, Haiguang; Jin, Lei; Vetrone, Fiorenzo; Vomiero, Alberto; Rosei, Federico

    2016-01-01

    We report the fabrication and testing of dye sensitized solar cells (DSSC) based on tin oxide (SnO2) particles of average size ~20 nm. Fluorine-doped tin oxide (FTO) conducting glass substrates were treated with TiOx or TiCl4 precursor solutions to create a blocking layer before tape casting the SnO2 mesoporous anode. In addition, SnO2 photoelectrodes were treated with the same precursor solutions to deposit a TiO2 passivating layer covering the SnO2 particles. We found that the modification enhances the short circuit current, open-circuit voltage and fill factor, leading to nearly 2-fold increase in power conversion efficiency, from 1.48% without any treatment, to 2.85% achieved with TiCl4 treatment. The superior photovoltaic performance of the DSSCs assembled with modified photoanode is attributed to enhanced electron lifetime and suppression of electron recombination to the electrolyte, as confirmed by electrochemical impedance spectroscopy (EIS) carried out under dark condition. These results indicate that modification of the FTO and SnO2 anode by titania can play a major role in maximizing the photo conversion efficiency. PMID:26988622

  18. Structural, optical and photovoltaic properties of co-doped CdTe QDs for quantum dots sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Ayyaswamy, Arivarasan; Ganapathy, Sasikala; Alsalme, Ali; Alghamdi, Abdulaziz; Ramasamy, Jayavel

    2015-12-01

    Zinc and sulfur alloyed CdTe quantum dots (QDs) sensitized TiO2 photoelectrodes have been fabricated for quantum dots sensitized solar cells. Alloyed CdTe QDs were prepared in aqueous phase using mercaptosuccinic acid (MSA) as a capping agent. The influence of co-doping on the structural property of CdTe QDs was studied by XRD analysis. The enhanced optical absorption of alloyed CdTe QDs was studied using UV-vis absorption and fluorescence emission spectra. The capping of MSA molecules over CdTe QDs was confirmed by the FTIR and XPS analyses. Thermogravimetric analysis confirms that the prepared QDs were thermally stable up to 600 °C. The photovoltaic performance of alloyed CdTe QDs sensitized TiO2 photoelectrodes were studied using J-V characteristics under the illumination of light with 1 Sun intensity. These results show the highest photo conversion efficiency of η = 1.21%-5% Zn & S alloyed CdTe QDs.

  19. Hydrogenated TiO{sub 2} film for enhancing photovoltaic properties of solar cells and self-sensitized effect

    SciTech Connect

    He, Hongcai; Yang, Kui; Wang, Ning Luo, Feifei; Chen, Haijun

    2013-12-07

    Hydrogenated TiO{sub 2} film was obtained by annealing TiO{sub 2} film at 350 °C for 2 h with hydrogen, and TiO{sub 2} films were prepared by screen printing on fluorine-doped tin oxide glass. Structural characterization by X-ray diffraction and electron microscopy did not show obvious difference between hydrogenated TiO{sub 2} film and pristine TiO{sub 2} film. Through optical and electrochemical characterization, the hydrogenated TiO{sub 2} film showed enhanced absorption and narrowed band gap, as well as reduced TiO{sub 2} surface impedance and dark current. As a result, an obviously enhanced photovoltaic effect was observed in the solar cell with hydrogenated TiO{sub 2} as photoanode without adding any dye due to the self-sensitized effect of hydrogenated TiO{sub 2} film, which excited electrons injecting internal conduction band of TiO{sub 2} to generate more photocurrent.

  20. Effect of sulfur doped TiO2 on photovoltaic properties of dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Seo, Hyunwoong; Nam, Sang-Hun; Itagaki, Naho; Koga, Kazunori; Shiratani, Masaharu; Boo, Jin-Hyo

    2016-07-01

    In a dye-sensitized solar cell (DSC), a nano-porous semiconductor layer plays an important role in the performance. It determines open-circuit voltage and it affects the dye adsorption capacity and charge transfer, which are closely associated with photocurrent and overall performance. TiO2 is the most proper material for nano-porous layer since the first development of DSCs. This work focuses on the enhancement of TiO2 by doping. Sulfur (S) doping enhances charge transfer and the photoconversion of TiO2. Therefore, the increase in photocurrent and efficiency is expected by S doping. S is doped into TiO2 by hydrolysis method. The amount of S is varied and their photo-responses are verified. The most effective S doped TiO2 is applied to DSCs. Overall performance of DSC is enhanced by the addition of S doped TiO2. Especially, the photocurrent is much increased by the improvement on charge transfer, electron lifetime, and photo-conversion. The photovoltaic properties of DSCs are investigated with various ratios of undoped and S doped TiO2. Finally, a DSC based on undoped and S doped TiO2 ratio of 1:1 has the highest efficiency, better than that of a standard DSC based on undoped TiO2. [Figure not available: see fulltext.

  1. Enhanced photovoltaic properties in dye sensitized solar cells by surface treatment of SnO2 photoanodes

    PubMed Central

    Basu, Kaustubh; Benetti, Daniele; Zhao, Haiguang; Jin, Lei; Vetrone, Fiorenzo; Vomiero, Alberto; Rosei, Federico

    2016-01-01

    We report the fabrication and testing of dye sensitized solar cells (DSSC) based on tin oxide (SnO2) particles of average size ~20 nm. Fluorine-doped tin oxide (FTO) conducting glass substrates were treated with TiOx or TiCl4 precursor solutions to create a blocking layer before tape casting the SnO2 mesoporous anode. In addition, SnO2 photoelectrodes were treated with the same precursor solutions to deposit a TiO2 passivating layer covering the SnO2 particles. We found that the modification enhances the short circuit current, open-circuit voltage and fill factor, leading to nearly 2-fold increase in power conversion efficiency, from 1.48% without any treatment, to 2.85% achieved with TiCl4 treatment. The superior photovoltaic performance of the DSSCs assembled with modified photoanode is attributed to enhanced electron lifetime and suppression of electron recombination to the electrolyte, as confirmed by electrochemical impedance spectroscopy (EIS) carried out under dark condition. These results indicate that modification of the FTO and SnO2 anode by titania can play a major role in maximizing the photo conversion efficiency. PMID:26988622

  2. Full-ionic liquid gel electrolytes: Enhanced photovoltaic performances in dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Li, Qinghua; Tang, Qunwei; He, Benlin; Yang, Peizhi

    2014-10-01

    Liquid electrolytes containing redox species have been widely used in dye-sensitized solar cells (DSSCs), whereas the volatility of organic solvents has been a tremendous obstacle for their commercial application. To assemble durable DSSCs, here we report the synthesis of full-ionic liquid electrolyte, in which 1-butyl-3-methylimidazolium nitrate is employed as solvent and 1-methyl-3-propylimidazolium iodide is iodide source. Using the imbibition performance of amphiphilic poly(acrylic acid/gelatin) [poly(AA/GR)] and poly(acrylic acid/cetyltrimethyl ammonium bromide) [poly(AA/CTAB)] matrices, full-ionic liquid electrolytes are imbibed into three-dimensional framework of poly(AA/GR) or poly(AA/CTAB) to form stable gel electrolytes. Room-temperature ionic conductivities as high as 17.82 and 18.44 mS cm-1 are recorded from full-ionic liquid imbibed poly(AA/GR) and poly(AA/CTAB) gel electrolytes, respectively. Promising power conversion efficiencies of 7.19% and 7.15% are determined from their DSSC devices in comparison with 6.55% and 6.12% from traditional acetonitrile-based poly(AA/GR) and poly(AA/CTAB) gel electrolytes, respectively. The new concept along with easy fabrication demonstrates the full-ionic liquid electrolytes to be good alternatives for robust gel electrolytes in quasi-solid-state DSSCs.

  3. Graphite-based photovoltaic cells

    DOEpatents

    Lagally, Max; Liu, Feng

    2010-12-28

    The present invention uses lithographically patterned graphite stacks as the basic building elements of an efficient and economical photovoltaic cell. The basic design of the graphite-based photovoltaic cells includes a plurality of spatially separated graphite stacks, each comprising a plurality of vertically stacked, semiconducting graphene sheets (carbon nanoribbons) bridging electrically conductive contacts.

  4. Thin film solar cell workshop

    NASA Technical Reports Server (NTRS)

    Armstrong, Joe; Jeffrey, Frank

    1993-01-01

    A summation of responses to questions posed to the thin-film solar cell workshop and the ensuing discussion is provided. Participants in the workshop included photovoltaic manufacturers (both thin film and crystalline), cell performance investigators, and consumers.

  5. The influence of annealing temperature on the interface and photovoltaic properties of CdS/CdSe quantum dots sensitized ZnO nanorods solar cells.

    PubMed

    Qiu, Xiaofeng; Chen, Ling; Gong, Haibo; Zhu, Min; Han, Jun; Zi, Min; Yang, Xiaopeng; Ji, Changjian; Cao, Bingqiang

    2014-09-15

    Arrays of ZnO/CdS/CdSe core/shell nanocables with different annealing temperatures have been investigated for CdS/CdSe quantum dots sensitized solar cells (QDSSCs). CdS/CdSe quantum dots were synthesized on the surface of ZnO nanorods that serve as the scaffold via a simple ion-exchange approach. The uniform microstructure was verified by scanning electron microscope and transmission electron microscope. UV-Visible absorption spectrum and Raman spectroscopy analysis indicated noticeable influence of annealing temperature on the interface structural and optical properties of the CdS/CdSe layers. Particularly, the relationship between annealing temperatures and photovoltaic performance of the corresponding QDSSCs was investigated employing photovoltaic conversion, quantum efficiency and electrochemical impedance spectra. It is demonstrated that higher cell efficiency can be obtained by optimizing the annealing temperature through extending the photoresponse range and improving QD layer crystal quality. PMID:24998074

  6. Enhanced photovoltaic performance of inverted pyramid-based nanostructured black-silicon solar cells passivated by an atomic-layer-deposited Al2O3 layer.

    PubMed

    Chen, Hong-Yan; Lu, Hong-Liang; Ren, Qing-Hua; Zhang, Yuan; Yang, Xiao-Feng; Ding, Shi-Jin; Zhang, David Wei

    2015-10-01

    Inverted pyramid-based nanostructured black-silicon (BS) solar cells with an Al2O3 passivation layer grown by atomic layer deposition (ALD) have been demonstrated. A multi-scale textured BS surface combining silicon nanowires (SiNWs) and inverted pyramids was obtained for the first time by lithography and metal catalyzed wet etching. The reflectance of the as-prepared BS surface was about 2% lower than that of the more commonly reported upright pyramid-based SiNW BS surface over the whole of the visible light spectrum, which led to a 1.7 mA cm(-2) increase in short circuit current density. Moreover, the as-prepared solar cells were further passivated by an ALD-Al2O3 layer. The effect of annealing temperature on the photovoltaic performance of the solar cells was investigated. It was found that the values of all solar cell parameters including short circuit current, open circuit voltage, and fill factor exhibit a further increase under an optimized annealing temperature. Minority carrier lifetime measurements indicate that the enhanced cell performance is due to the improved passivation quality of the Al2O3 layer after thermal annealing treatments. By combining these two refinements, the optimized SiNW BS solar cells achieved a maximum conversion efficiency enhancement of 7.6% compared to the cells with an upright pyramid-based SiNWs surface and conventional SiNx passivation. PMID:26243694

  7. Nanoscience and Nanostructures for Photovoltaics and Solar Fuels

    SciTech Connect

    Nozik, Arthur J.

    2010-07-02

    Quantum confinement of electronic particles (negative electrons and positive holes) in nanocrystals produces unique optical and electronic properties that have the potential to enhance the power conversion efficiency of solar cells for photovoltaic and solar fuels production at lower cost. These approaches and applications are labeled third generation solar photon conversion. Prominent among these unique properties is the efficient formation of more than one electron-hole pair (called excitons in nanocrystals) from a single absorbed photon. In isolated nanocrystals that have three-dimensional confinement of charge carriers (quantum dots) or two-dimensional confinement (quantum wires and rods) this process is termed multiple exciton generation. This Perspective presents a summary of our present understanding of the science of optoelectronic properties of nanocrystals and a prognosis for and review of the technological status of nanocrystals and nanostructures for third generation photovoltaic cells and solar fuels production.

  8. Carbon Nanotube-Silicon Nanowire Heterojunction Solar Cells with Gas-Dependent Photovoltaic Performances and Their Application in Self-Powered NO2 Detecting

    NASA Astrophysics Data System (ADS)

    Jia, Yi; Zhang, Zexia; Xiao, Lin; Lv, Ruitao

    2016-06-01

    A multifunctional device combining photovoltaic conversion and toxic gas sensitivity is reported. In this device, carbon nanotube (CNT) membranes are used to cover onto silicon nanowire (SiNW) arrays to form heterojunction. The porous structure and large specific surface area in the heterojunction structure are both benefits for gas adsorption. In virtue of these merits, gas doping is a feasible method to improve cell's performance and the device can also work as a self-powered gas sensor beyond a solar cell. It shows a significant improvement in cell efficiency (more than 200 times) after NO2 molecules doping (device working as a solar cell) and a fast, reversible response property for NO2 detection (device working as a gas sensor). Such multifunctional CNT-SiNW structure can be expected to open a new avenue for developing self-powered, efficient toxic gas-sensing devices in the future.

  9. Carbon Nanotube-Silicon Nanowire Heterojunction Solar Cells with Gas-Dependent Photovoltaic Performances and Their Application in Self-Powered NO2 Detecting.

    PubMed

    Jia, Yi; Zhang, Zexia; Xiao, Lin; Lv, Ruitao

    2016-12-01

    A multifunctional device combining photovoltaic conversion and toxic gas sensitivity is reported. In this device, carbon nanotube (CNT) membranes are used to cover onto silicon nanowire (SiNW) arrays to form heterojunction. The porous structure and large specific surface area in the heterojunction structure are both benefits for gas adsorption. In virtue of these merits, gas doping is a feasible method to improve cell's performance and the device can also work as a self-powered gas sensor beyond a solar cell. It shows a significant improvement in cell efficiency (more than 200 times) after NO2 molecules doping (device working as a solar cell) and a fast, reversible response property for NO2 detection (device working as a gas sensor). Such multifunctional CNT-SiNW structure can be expected to open a new avenue for developing self-powered, efficient toxic gas-sensing devices in the future. PMID:27299654

  10. Polycrystalline photovoltaic cell

    SciTech Connect

    Jordan, J.F.; Lampkin, C.M.

    1983-10-25

    A photovoltaic cell is disclosed, having an electrically conductive substrate, which may be glass having a film of conductive tin oxide; a first layer containing a suitable semiconductor, which layer has a first component film with an amorphous structure and a second component film with a polycrystalline structure; a second layer forming a heterojunction with the first layer; and suitable electrodes where the heterojunction is formed from a solution containing copper, the amorphous film component is superposed above an electrically conductive substrate to resist permeation of the copper-containing material to shorting electrical contact with the substrate. The penetration resistant amorphous layer permits a variety of processes to be used in forming the heterojunction with even very thin layers (1-6 /SUB u/ thick) of underlying polycrystalline semiconductor materials. In some embodiments, the amorphous-like structure may be formed by the addition of aluminum or zirconium compounds to a solution of cadmium salts sprayed over a heated substrate.