This report describes work performed by Energy Conversion Devices, Inc. (ECD) under a 3-year, cost-shared amorphous silicon (a-Si) research program to develop advanced technologies and to demonstrate stable 14%-efficient, triple-junction a-Si alloy solar ...

The objectives for the University of Toledo are to: (1) establish a transferable knowledge and technology base for fabricating high-efficiency triple-junction a-Si-based solar cells, and (2) develop high-rate deposition techniques for the growing a-Si-based and related alloys, including poly-Si, c-Si, ...

This report describes work performed by Energy Conversion Devices, Inc. (ECD) under a 3-year, cost-shared amorphous silicon (a-Si) research program to develop advanced technologies and to demonstrate stable 14%-efficient, triple-junction a-Si alloy solar cells. The technologies developed under the program will then ...

a-Si/a-SiGe/a-SiGe flexible PV products on stainless steel The development of space solar cells on polymer substrate has leveraged the terrestrial technology Green Power...

The principal objective of this R&D program is to expand, enhance, and accelerate knowledge and capabilities for development of high-efficiency hydrogenated amorphous silicon (a-Si:H) and amorphous silicon-germanium alloy (a-SiGe:H) related thin-film multijunction solar cells and modules with low ...

We prototype an alternative n-type monocrystalline silicon (c-Si) solar cell structure that utilizes an n/i-type hydrogenated amorphous silicon (a-Si:H) front hetero-contact and a back p-n junction formed by alloying aluminum (Al) with the n-type Si wafer...

We prototype an alternative n-type monocrystalline silicon (c-Si) solar cell structure that utilizes an n/i-type hydrogenated amorphous silicon (a-Si:H) front hetero-contact and a back p-n junction formed by alloying aluminum (Al) with the n-type Si wafer.

This report describes results achieved during phase 1 of a three-phase subcontract to develop and understand thin-film solar cell technology associated to CuInSe(sub 2) and related alloys, a-Si and its alloys, and CdTe. Modules based on all these thin fil...

This report describes the project by Energy Conversion Devices, Inc. (ECD) and its American joint venture, United Solar Systems Corp. (United Solar), to develop and commercialize a roll-to-roll triple-junction amorphous silicon alloy PV manufacturing tech...

Amorphous silicon alloy based triple junction solar cells and modules with initial efficiencies of approximately 11% have been developed. These devices are expected to exhibit less than a 20% loss before stabilizing. An improved transparent front contact and silicon carbide alloys promise to raise conversion efficiencies to 13%--14%.

This book contains papers presented at the Twentieth IEEE Photovoltaic Specialists Conference. Some of the topics covered are: Issues and opportunities in space photovoltaics; A novel design for amorphous silicon alloy solar cells; New materials and new analysis method for high efficiency a-Si solar cells; and high ...

This report describes a roll-to-roll triple-junction amorphous silicon alloy PV manufacturing technology developed and commercialized by Energy Conversion Devices (ECD) and United Solar Systems. This low material cost, roll-to-roll production technology h...

This annual describes the research results of the JPL Flat Plate Solar Photovoltaic Research Project, which is sponsored by the US Department of Energy and is part of the National Photovoltaics Program to initiate a major effort toward the development of cost- competitive solar arrays. Electron cyclotron resonance (ECR) microwave plasma depositions of ...

We have developed hydrogenated amorphous silicon (a Si:H) back contacts to both p- and n-type silicon wafers, and employed them in double-heterojunction solar cells. These contacts are deposited entirely at low temperature (<250 C) and replace the standard diffused or alloyed back-surface-field contacts used ...

This report describes a 21-month project to demonstrate amorphous-silicon (a-Si) solar cells with high stabilized conversion efficiency. The objective was to develop a research program spanning material issues (more stable a-Si and better a-SiGe alloys) and device issues (more stable ...

Presented at the 2001 NCPV Program Review Meeting: High-quality high-deposition-rate (10 angstrom/s) a-SiGe:H alloy solar cells have been made by hot-wire chemical-vapor deposition. High-quality high-deposition-rate (10 {angstrom}/s) amorphous silicon germanium (a-SiGe:H) alloy ...

This report describes a research program to investigate hydrogenated amorphous silicon-germanium alloys (a-Sil-xGex:H) for solar-cell applications. Specifically, studies were carried out to determine why these low-band-gap alloys exhibit photo-electronic properties inferior to those of hydrogenated amorphous silicon ...

Energy Conversion Devices, Inc. (ECD) has designed and constructed a 2 Megawatt (mW) manufacturing line that produces triple-junction spectrum-splitting a-Si alloy solar cells in a continuous roll-to-roll process. This manufacturing line has reliably and consistently produced high efficiency solar cells. We have ...

This research program is directed toward the advancement of understanding of amorphous silicon-based alloys and their use in small area multi-junction solar cells. The program is divided into subtasks on materials research, single-junction solar cell research, and multi-junction solar cell research. In this report ...

This report summarizes Energy Conversion Devices, Inc.`s (ECD) research under this program. ECD researchers explored the deposition of a-Si at high rates using very-high-frequency plasma MHz, and compared these VHF i-layers with radio-frequency (RF) plasma-deposited i-layers. ECD conducted comprehensive research to develop a {mu}c-Si p{sup +} layer using VHF deposition process with the objectives ...

This report documents the results of material development, single- junction solar cell research, and high-efficiency multijunction cell development. High-quality a-Si:Ge:H:F alloys were made with optical band gaps as low as 1.3 eV; high-conductivity micro...

This report summarizes Energy Conversion Devices, Inc.'s (ECD) research under this program. ECD researchers explored the deposition of a-Si at high rates using very-high-frequency plasma MHz, and compared these VHF i-layers with radio-frequency (RF) plasm...

The work carried out by the University of Oregon Under this subcontract focused on the characterization and evaluation of low-gap (a-Si,Ge:H) alloy materials and on issues related to overall stability in the mid-gap (a-SiH) materials. First, researchers characterized an extensive series of Uni-Solar ...

SCHOTT Solar a-Si Plant SCHOTT AG said it will spend about $72 million to build a thin-film solar module factory in Jena, Germany. See coverage at RenewableEnergyAccess:

This report describes work to develop a state-of-the-art electron cyclotron resonance (ECR) plasma-enhanced chemical vapor deposition (PECVD) system. The objective was to understand the deposition processes of amorphous silicon (a-Si:H) and related alloys, with a best-effort improvement of optoelectronic material properties and best-effort stabilization of ...

This report describes work to develop a state-of-the-art electron cyclotron resonance (ECR) plasma-enhanced chemical vapor deposition (PECVD) system. The objective was to understand the deposition processes of amorphous silicon (a-Si:H) and related alloys, with a best-effort improvement of optoelectronic material properties and best-effort stabilization of ...

Computer simulations are reported of hydrogenated amorphous silicon germanium (a-SiGe:H) layers that make up the graded part of the intrinsic layer near the interfaces of a-SiGe:H solar cells. Therefore the graded part is approached with a staircase bandgap profile, consisting of three layers within which the material properties are constant. Calibrated ...

The authors report on the development of helium diluted a-Si:H and a-SiGe:H solar cells with higher deposition rates and better feedstock utilization than devices made with hydrogen dilution. Both the initial and the stabilized efficiencies of the He-diluted single-junction a-Si:H and a-SiGe:H cells are similar to those of ...

TRIPLE-JUNCTION A-SI SOLAR CELLS WITH HEAVILY DOPED THIN INTERFACE LAYERS AT THE TUNNEL JUNCTIONS W of Toledo, Toledo, OH 43606 USA ABSTRACT Triple-junction a-Si based solar cells, having a structure of SS cells and between the middle and bottom component cells on the efficiency of triple- junction ...

various problems experienced by SMUD' s main a-Si supplier - Fig. 7: East End a-Si BIPV Curtain Wall 7 primarily delays in getting the new CalSolar a-Si PV factory to normal...

Photovoltaic research conducted in four areas is described: semiconductor materials, high-efficiency cells, nonsemiconductor materials, and submodules. The major focus of semiconductor materials research was on improving the quality of wide-band-gap a-SiC:H alloys and narrow-band-gap a-SiGe:H alloys. Raman ...

Research progress on amorphous Si:H solar cells is described. Tasks include theoretical modeling, deposition and doping studies, experimental characterization of a-Si:H, formation of solar cell structures, and evaluation of solar cell parameters. A new method for determining the drift mobility of majority carriers in doped ...

United Solar used a-Si:H/a-SiGe:H/a-SiGe:H in two manufacturing plants and improved solar efficiency and reduced manufacturing cost by new deposition methods, optimized deposition parameters, and new materials and cell structures.

A detailed study of the electronic density of states (DOS) in the gap of hydrogenated amorphous silicon (a-Si:H) and related alloys is presented. Three independent DOS measurements are employed: field effect, Schottky diode complex admittance, and space-charge-limited currents (SCLC). Refinements in the method of analysis are presented for each technique, ...

We have developed hydrogenated amorphous silicon (a-Si:H) back contacts to both p-and n-type silicon wafers, and employed them in double-heterojunction solar cells. These contacts are deposited entirely at low temperature (<250degC) and replace the standard diffused or alloyed back-surface-field contacts used in ...

United Solar Ovonic successfully used its spectrum-splitting a-Si:H/a-SiGe:H/a-SiGe:H triple-junction structure in their manufacturing plants, achieving a manufacturing capacity of 118 MW in 2007, and set up a very aggressive expansion plan to achieve grid parity.

Efficient hydrogenated amorphous silicon (a-Si:H) nip solar cells have been fabricated with all doped and undoped a-Si:H layers deposited by hot-wire chemical vapor deposition (HWCVD). The total deposition time of all layers, except the top ITO-contact, is less than 4 minutes.

The goal of this project is to determine the fundamental growth mechanisms of hydrogenated amorphous silicon (a-Si:H) and related alloys. This is important because thin films of these materials must have the high quality and stability required for 15%-efficient solar cells and be produced at high rates and low cost over large areas: ...

This report presents results of research on amorphous silicon- germanium alloys for tandem solar-cell applications. A study was completed of a-Si{sub 1 {minus} x}Ge{sub x}:H and a-Si{sub 1 {minus} x}Ge{sub x}:H:F alloys. This included extensive structural examination by transmission electron spectroscopy, gas evolution, and ...

a-Si 1-x Ge x :H materials for high performance solar cells. Construction of a new Dual Beam Photoconductivity (DBP) apparatus has been completed, and the new capabilities are...

Under the PVMat 2A Program, Energy Conversion Devices, Inc. (ECD) has performed manufacturing technology development work utilizing its proprietary continuous roll-to-roll triple-junction a-Si alloy solar cell production line. Among the accomplishments achieved under this program, ECD demonstrated the production of the ...

Thin semiconducting films of hydrogenated amorphous silicon (a-Si:H) and its carbon alloy (a-Si:C:H) were applied to gas microstrip detectors in order to control gain instabilities due to charges on the substrate. Thin ((approximately)100nm) layers of a-S...

This report describes the research program intended to expand, enhance, and accelerate knowledge and capabilities for developing high-performance, two-terminal multijunction amorphous silicon (a-Si) alloy cells, and modules with low manufacturing cost and high reliability. United Solar uses a spectrum-splitting, triple-junction cell ...

This report describes work done by the University of Toledo during the first year of this subcontract. During this time, the CdTe group constructed a second dual magnetron sputter deposition facility; optimized reactive sputtering for ZnTe:N films to achieve 10 ohm-cm resistivity and {approximately}9% efficiency cells with a copper-free ZnTe:N/Ni contact; identified Cu-related photoluminescence ...

The performance and stability of {ital a}-SiGe:H single junction {ital p}-{ital i}-{ital n} solar cells with interfacial layers at the {ital p}/{ital i} and the {ital i}/{ital n} interfaces are reported. It is found that interfacial layers have a strong influence both on the initial performance as well as on the stability of these devices. The device ...

This research program was originally defined to investigate the deposition of semiconductor and dielectric thin films using a low pressure remote plasma chemical vapor deposition system incorporating a process for etching the films. This etching was to be performed in a periodic fashion during the deposition process to remove defect regions in the film being deposited. The goal was to remove voids ...

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 ...

The transport properties of a-Si,Ge:H,F/a-Si:H,F superlattices are analyzed from the viewpoint of their use as low-bandgap absorbers in solar cells. Photo-to-dark conductivity ratios measured perpendicular to the layer planes are reported for a bandgap range from 1.26 eV to 1.45 eV. A recently developed theory of carrier transport in superlattices is used to establish the ...

The effort at University of Delaware during the first three months of a Department of Energy sponsored a-Si program is described. The objectives of the program are to study and improve photovoltaic properties of plasma-deposited a-Si and model a-Si device...

In this report, the authors describe the work done to improve the material and device properties of a-Si:H and a-(Si,Ge):H alloys prepared using electron cyclotron resonance (ECR) plasma deposition and to understand the growth chemistry. Major results were obtained in the following areas: (1) Influence of plasma chemistry on properties and stability of a-Si:H single-junction ...

Integrated amorphous silicon (a-Si) solar panels have been developed and applied to an electric power generating system. The integrated a-Si solar panel consists of 20 integrated type a-Si solar cell modules, each with a size of 10 cm x 10 cm, which were developed for use ...

The present conference considers topics in the fields of thin film transistors, the physics of amorphous silicon (a-Si) devices and photoreceptors, and image and power sensors. Attention is given to a-Si FET requirements for LCD pixel switches, high barrier rectifying junctions with a-Si alloy electrodes and their application to LSI FETs, bulk limitation ...

The authors report on the fabrication and stability tests of single junction a-Si:H, and tandem junction a-Si:H/A-Si:H solar cells using the ECR process under high hydrogen dilution (H-ECR process). They show that devices with high fill factors can be made using the H-ECR process. They also report on the stability studies of the ...

of Energy Conversion University of Delaware Newark DE, USA Development of the transparent contact device and characterization techniques driven by need for better...

A flexible amorphous silicon (a-Si) based photovoltaic (PV) module has been developed. The a-Si solar cell fabricated on a heat-resistance plastic film with a thickness of 50{micro}m has a new monolithic series-connected structure named SCAF to obtain a high output voltage required for practical use. Applying a-Si/a-SiGe ...

A hydrogenated amorphous silicon ({ital a}-Si:H) {ital p}-{ital i}-{ital n} solar cell with a two-layer back electrode is proposed. The new type of back electrode consists of a conventional Al layer and an amorphous silicide layer. The properties of amorphous Cr-silicide film and thermal stability of {ital a}-Si:H {ital p}-{ital ...

This report describes research on high-efficiency, single-junction, monolithic, thin-film amorphous silicon solar cells in five task areas: a-Si materials; nonsemiconductor materials; a-Si solar cells; monolithic, intraconnected cells and submodules; and ...

Nevada Nanotechnology Center and Si group at NREL will work together to develop a-Si based solar cells with nano-Si technique. We will explore the existing a-Si based film solar cell technology at NREL and nano scale Si technology at Nevada Nanotechnology...

This report describes work done in Phase 2 of a 3-year project to advance Energy Conversion Devices, Inc. (ECD), roll-to-roll, triple-junction photovoltaic manufacturing technologies, to reduce the module production costs, to increase the stabilized module performance, and to expand the commercial capacity utilizing ECD technology. Major accomplishments in Phase 2 include: (1) designing, ...

This final report describes results achieved under a 20-month NREL subcontract to develop and understand thin-film solar cell technology associated to CuInSe{sub 2} and related alloys, a-Si and its alloys, and CdTe. Modules based on all these thin films are promising candidates to meet DOE's long-range ...

This report describes results achieved during phase I of a four-phase subcontract to develop and understand thin-film solar cell technology associated with CuInSe2 and related alloys, a-Si and its alloys, and CdTe. Modules based on all these thin films are promising candidates to meet DOE long-range efficiency, ...

This report describes results achieved during a three-year subcontract to develop and understand thin-film solar cell technology associated to CuInSe2 and related alloys, a-Si and its alloys, and CdTe. Modules based on all these thin films are promising candidates to meet DOE long-range efficiency, reliability, and ...

This report describes the results achieved during Phase I of a three-phase subcontract to develop and understand thin-film solar cell technology associated with CuInSe2 and related alloys, a-Si and its alloys, and CdTe. Modules based on all these thin films are promising candidates to meet DOE long-range ...

This report describes results achieved during phase 1 of a three-phase subcontract to develop and understand thin-film solar cell technology associated to CuInSe{sub 2} and related alloys, a-Si and its alloys, and CdTe. Modules based on all these thin films are promising candidates to meet DOE long-range ...

This subcontract report describes how Energy Conversion Devices, Inc., has developed and built 7 generations of roll-to-roll amorphous silicon PV production equipment. In the ECD/United Solar production process, we deposit about a 1-mm-thick, 12-layer coating consisting of a metal/oxide backreflector, a 9-layer a-Si/a-SiGe alloy ...

Energy Conversion Devices, Inc. (ECD) has developed and built 7 generations of roll-to-roll amorphous silicon PV production equipment. In the ECD/United Solar Ovonic production process, we deposit about a 1-mm-thick, 12-layer coating consisting of a metal/oxide backreflector, a - layer a-Si/a-SiGe alloy triple-junction ...

United Solar finishes solar cell (deposits 0.25 cm2 p+/ITO top contacts) United Solar measures device performance (plus QE on selected devices) Pure a-Si:H i-layer results (no...

The interfaces between hydrogenated amorphous silicon-carbon alloy and amorphous silicon, both hydrogenated and not, were investigated by photoemission spectroscopy. It is found that the valence-band discontinuity is 0.15 +- 0.1 eV for the amorphous Si case and zero within the experimental uncertainty for the hydrogenated amorphous Si. The relevance of this result for ...

This report describes the status and accomplishments of work performed under this subcontract by United Solar Systems. United Solar researchers explored several new deposition regimes/conditions to investigate their effect on material/device performance. To facilitate optimum ion bombardment during growth, a large parameter space involving chamber ...

The density of localized gap states in the bulk and in the near-surface region of amorphous hydrogenated silicon (a-Si:H) was measured for non oxidized undoped, B-doped and P-doped samples as well as for films with low carbon (C) and germanium (Ge) conten...

This report describes work performed to develop improved p-type wide-band-gap hydrogenated amorphous silicon-carbon alloy (a-Si{sub 1-x}C{sub x:}H) thin films and interfaces for the ``top junction`` in hydrogenated amorphous silicon (a-Si:H)-based p-i-n solar cells. We used direct current reactive magnetron ...

The initial task was to develop a flexible glow discharge apparatus capable of yielding reproducible uniform films of a-Si(H) to provide a reference material for comparison with subsequent alloyed materials. Following the completion of this task, C substituted and Ge substituted a-Si/sub x/M/sub 1-x/(H) alloys were prepared over a ...

This research was conducted to determine the potential of photochemical vapor deposition (photo-CVD) for producing high-quality, low-band-gap amorphous silicon germanium alloys for use in high-efficiency, multijunction, thin-film photovoltaic solar cells. A photo-CVD reactor for mercury-sensitized photolysis of silane-germane and disilane-germane mixtures ...

This report describes the research performed during Phase II of a three-phase, three-year program under NREL Subcontract No. ZAN-4-13318-02. The research program is intended to expand, enhance and accelerate knowledge and capabilities for the development of high-performance, two-terminal multijunction hydrogenated amorphous silicon (a-Si:H) alloy modules. ...

We have developed hydrogenated amorphous silicon (a Si:H) back contacts to both p- and n-type silicon wafers, and employed them in double-heterojunction solar cells. These contacts are deposited entirely at low temperature (

A technique for measuring the electrical characteristics of contacts to doped hydrogenated amorphous silicon (a-Si:H) or other high-resistivity thin-film semiconductors is developed. Experimental results for metal and conductive transparent oxide contacts to both n- and p-type a-Si:H are presented and the significance of these values to ...

Hydrogenated a-Si solar cells were prepared by rf-sputtering. It was found that for a-Si the surface microstructure of sputtered films can be altered by a simple post-deposition etching process and controlled by varying the film preparation conditions. It...

High open-circuit voltage (V{sub oc}) silicon heterojunction (SHJ) solar cells are fabricated in double-heterojunction a-Si:H/c-Si/a-Si:H structures using low temperature (< 225 C) hydrogenated amorphous silicon (a-Si:H) contacts deposited by hot-wire chemical vapor deposition (HWCVD). On p-type c-Si float-zone wafers, we used ...

The use of ethylene (C/sub 2/H/sub 4/) rather than methane (CH/sub 4/) as the source of carbon in the hydrogenated amorphous silicon carbide (a-SiC:H) p/sup +/ layer of hydrogenated amorphous silicon (a-Si:H) based solar cells deposited in a glow discharge has been explored. Device results are presented to demonstrate the utility of ...

The influence of atmospheric contaminants oxygen and nitrogen on the performance of thin-film hydrogenated amorphous silicon (a-Si:H) solar cells grown by plasma-enhanced chemical vapor deposition at 13.56 MHz was systematically investigated. The question is addressed as to what degree of high base pressures (up to 10-4 Torr) are compatible with the ...

Under the PV:BONUS Program, ECD and United Solar developed, demonstrated and commercialized two new lightweight, flexible BIPV modules specifically designed as replacements for conventional asphalt shingles and standing seam metal roofing. These modules can be economically and aesthetically integrated into new residential and commercial buildings, and can be used to address ...

In high efficiency narrow bandgap (NBG) a-SiGe solar cells, thin buffer layers of unalloyed hydrogenated amorphous silicon (a-Si) are usually used at the interfaces between the a-SiGe intrinsic layer and the doped layers. They investigated the effect of inserting additional a-SiGe interface layers between these ...

A process has been developed for fabrication of roll-up, monolithic, photovoltaic (PV) modules made of amorphous silicon (a-Si) alloys. They consist of tandem-junction solar cells deposited by a continuous, roll-to-roll process onto thin, foil substrates of bare metal, high temperature resin, or metal coated with insulators. They have ...

This report documents the results of material development, single- junction solar cell research, and high-efficiency multijunction cell development. High-quality a-Si:Ge:H:F alloys were made with optical band gaps as low as 1.3 eV; high-conductivity microcrystalline p{sup +} and n{sup +} doped alloys were developed ...

Hydrogenated amorphous silicon (a-Si:H) is a semiconductor that can be used for thin film solar cells. In the work the properties of a-Si:H that are relevant to the performance of a-Si:H solar cells are studied. The scope of the thesis is the optical prop...

also reported. 1. Objectives General project objectives of "The Fabrication and Characterization of High-efficiency Triple-junction a-Si Based Solar Cells" are to establish a...

DEVICE PERFORMANCES AND SIMULATIONS FOR SEVERAL KINDS OF LARGE-SCALE THIN FILM SILICON SOLAR CELL MODULES -INTRODUCTION OF SUPER SEE-THROUGH THIN FILM SOLAR CELL MODULE AND...

This report describes work done under a 3-year program to advance ECD`s roll-to-roll, triple-junction photovoltaic manufacturing technologies, to reduce the module production costs, to increase the stabilized module performance, and to expand commercial capacity utilizing ECD technology. The specific 3-year goal is to develop advanced large-scale manufacturing technology incorporating ECD`s ...

This report describes the research on high-efficiency CdTe-based thin-film solar cells and on high-efficiency a-Si-based thin-film solar cells. Implemented a diode-array spectrograph system and used optical emission spectroscopy to help optimize the reactive sputtering of N-doped ZnTe for CdTe back-contact structures. Identified the ...

Solar cells fabricated using plasma-deposited a-Si:H alloys can be seriously degraded by the incorporation of certain impurities during deposition of the a-Si:H materials. Nominally intrinsic layers are adversely affected by the addition to the plasma of air, N/sub 2/ + O/sub 2/ mixtures (although by neither N/sub 2/ nor O/sub 2/ ...

Nevada Nanotechnology Center and Si group at NREL will work together to develop a-Si based solar cells with nano-Si technique. We will explore the existing a-Si based film solar cell technology at NREL and nano scale Si technology at Nevada Nanotechnology Center. By exchanging information, we will come; up with ...

This report describes the project by Energy Conversion Devices, Inc. (ECD) and its American joint venture, United Solar Systems Corp. (United Solar), to develop and commercialize a roll-to-roll triple-junction amorphous silicon alloy PV manufacturing technology. This low material cost, roll-to-roll production technology has the ...

Two main technologies for low cost solar cells using amorphous silicon (a-Si) film have been developed. A new PCVD (Plasma Chemical Vapor Deposition) fabrication process in which p,i, and n layers of a-Si are deposited in consecutive, separated reaction chambers, has been developed. In this process, high quality a-Si films are ...

A two-dimensional numerical computer analysis for thin-film-based hydrogenated amorphous silicon (i.e. a-Si : H) solar cells is presented. A comparative performance assessment for various absorbing layers such as a-Si, a-SiGe, a-SiC, combined a-Si+a-SiGe, a-Si/a-SiGe-graded ...

[9,10]. After careful analysis of these results, we now have a viable alternative explanation for the oxygen induced changes in a- Si,Ge:H alloys. Specifically, we believe our...

fractions of 0, 15, 29, 47, 63, 81, and 100at.% were obtained from Yueqin Xu and Harv Mahan at NREL. These 1.2 to 1.6 micron thick alloy films were deposited onto n + a-Si:H...

During the past year, approximately 300 large-area (400 cm exp 2 ) PIN hydrogenated amorphous silicon (a-Si:H) solar cells were fabricated and tested. a-Si:H PIN cells which were plasma deposited at 200 exp 0 to 350 exp 0 were found to have high internal ...

Hydrogen out-diffusion from the n/i interface region plays a major role in controlling the fill factor (FF) and resultant efficiency of n-i-p a-Si:H devices, with the i-layer deposited at high substrate temperatures by the hot wire technique. Modeling cal...

This report describes work performed to develop improved p-type wide-band-gap hydrogenated amorphous silicon-carbon alloy (a-Si(sub 1-x)C(sub x:)H) thin films and interfaces for the ''top junction'' in hydrogenated amorphous silicon (a-Si:H)-based p-i-n s...

Mesoporous nanocrystalline ZnO applied to a-Si/mesoporous tandem solar cell was synthesized through the hydrothermal method. The structures and morphologies were characterized by X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Brunauer-Emmett-Teller (BET) analysis based on the nitrogen adsorption isotherm. The test results indicated that the samples had an ...

This report describes a roll-to-roll triple-junction amorphous silicon alloy PV manufacturing technology developed and commercialized by Energy Conversion Devices (ECD) and United Solar Systems. This low material cost, roll-to-roll production technology has the economies of scale needed to meet the cost goals necessary for widespread use of PV. ECD has ...

We propose a nanostructured three-dimensional (nano-3D) solar cell design employing an ultrathin hydrogenated amorphous silicon (a-Si:H) n-i-p junction deposited on zinc oxide (ZnO) nanorod arrays. The ZnO nanorods were prepared by aqueous chemical growth at 80 �C. The photovoltaic performance of the nanorod/a-Si:H solar cell with an ...

We report the antireflective property of thin film amorphous silicon (a-Si) solar cell structures based on graded refractive index structure together with theoretical analysis. Optimizations of the index profile are performed using the rigorous coupled-wave analysis method. The graded refractive index structure fabricated by oblique angle deposition ...

Enormous progress has been made in recent years on a number of photovoltaic (PV) materials and devices in terms of conversion efficiencies. Ultrahigh-efficiency (>30{percent}) PV cells have been fabricated from gallium arsenide (GaAs) and its ternary alloys such as gallium indium phosphide (GaInP{sub 2}). The high-efficiency GaAs-based solar cells ...

In Section II, Theoretical Modeling, theories for the capture of electrons by deep centers in hydrogenated amorphous silicon (a-Si:H) and for field-dependent quantum efficiency in a-Si:H are presented. In Section III, Deposition and Doping Studies, the optimization of phosphorus-doped a-Si:H carried out in four different discharge systems is described. ...

Thin semiconducting films of hydrogenated amorphous silicon (a-Si:H) and its carbon alloy (a-Si:C:H) were applied to gas microstrip detectors in order to control gain instabilities due to charges on the substrate. Thin ({approximately}100nm) layers of a-Si:H or p-doped a-Si:C:H were placed either over or under the ...

This report describes results achieved during the second phase of a four year subcontract to develop and understand thin film solar cell technology related to a-Si and its alloys, CuIn(1-x)Ga(x)Se2, and CdTe. Accomplishments during this phase include development of equations and reaction rates for the formation of CuIn(1-x)Ga(x)Se2 films by selenization, ...

to use as an additional coating on active solar absorber surfaces. We have chosen p-i-n a-Si:H solar particles accumulate on the solar cell surface over time, blocking the sunlight and thus reducing the power (Figure 4b) with FIGURE 3. Power conversion of a-Si:H nanodome solar cells. (a) ...

This report contains the results of research on a-Si,Ge:H alloys (1) to study a-Si,Ge:H alloy films produced by dual magnetron sputtering from separate Si and Ge targets for photovoltaic device applications; (2) to determine the deposition conditions that...

Voltage of a-Si:H Solar Cells ? a-Si:H cells are low-mobility cells o By definition: slow carrier (hole) drift is the primary limitation to power generation in low-mobility...

A simple procedure for the application of a transparent-conducting coating onto a-Si:H devices is described. Results pertaining to a-Si:H solar-cell heterojunctions incorporating such coatings are given and discussed.

A method to form a:Si-H films at high rate and at reduced temperature would be of commercial value in the manufacture of solar cells and of semiconductor devices. A laser-based film formation process was developed, based on multiple infrared photon dissoc...

... Probing Amorphous Silicon Solar Cells Glass Transparent conducting oxide (SnO2) � 600 nm thick Boron doped (p-type) a-Si � 10 nm thick ...

distinctly different defects located at 1.0 and 1.2eV from the conduction band. The evolution of these defects under light induced degradation depends on the microstructure of...

the corresponding results from studies of films in which large differences in the evolution of two types of defect states has also been found 1 . The results obtained for the...

Oct 1, 1985 ... of submodules based on thin film amorphous silicon (a-Si) p i n solar cells. Starting from presently attainable single cell characteristics, ...

cell TCO a-Si heterojunction 2-10?m Conducting template Light Trapping benign grain boundary Example Solar Cell Concept <1?m Small ~100nm grains Random crystalline orientation...

Solar cells have been made from hydrogenated amorphous silicon (a- Si:H) films. The films including Si nanoparticles by 3% in the volume fraction have been found to possess good properties. In order to find the method to control this volume fraction, the ...

The interdigitated back contact silicon heterojunction (IBC-SHJ) solar cell requires a low temperature front surface passivation/anti-reflection structure. Conventional silicon surface passivation using SiO2 or a-SiNx is performed at temperature higher than 400°C, which is not suitable for the IBC-SHJ cell. In this paper, we propose a PECVD ...

The interdigitated back contact silicon heterojunction (IBC-SHJ) solar cell requires a low temperature front surface passivation/anti-reflection structure. Conventional silicon surface passivation using SiO2 or a-SiNx is performed at temperature higher than 400�C, which is not suitable for the IBC-SHJ cell. In this paper, we propose a PECVD ...

Hydrogenated, amorphous silicon (a-Si:H) is of great interest for thin film devices used, for example, for the transformation of photon energy and as semiconductor material. Important applications are thin film solar cells, thin film transistors for liqui...

Contents: Surface and Interface Analysis of Semiconductor Devices; Microstructure Analysis of Recording Disks; Analysis of Light-Induced Degradation in Amorphous Silicon (a-Si) Films for Solar Cells; Corrosion Control of Heat Exchangers in Electric Appara...

Best Large-Area, Thin Film Modules (standard conditions, aperture area) |Company|Device|Size (cm2)|Efficiency|Power|Date| |UniSolar|a-Si triple, laminate|21615|6.3%...

A remote silane plasma, capable of depositing solar grade a-Si:H at a rate of 10 nm/s and with an up to ten times higher hole drift mobility than standard a-Si:H, has been investigated by means of several plasma diagnostics. The creation of the different reactive species in the plasma and their contribution to film growth has been ...

This paper identifies the contributions of p�a�SiC:H layers and i�a�Si:H layers to the open circuit voltage of p�i�n type a�Si:H solar cells deposited at a low temperature of 125 �C. We find that poor quality p�a�SiC:H films under regular conditions lead to a restriction of open circuit voltage although the band gap ...

A series of environmental tests were completed on one type of triple junction a-Si and two types of CuInSe2 thin film solar cells. The environmental tests include electron irradiation at energies of 0.7, 1.0, and 2.0 MeV, proton irradiation at energies of...

of these features makes this a model system for investigating the achievable photo- voltaic efficiency improvements of photovoltaic power. Thin film Si solar cells using hydrogenated amorphous Si a-Si:H and nano- crystalline Si nc-Si:H are among the most well-developed thin film photovoltaic materials, but suffer from low diffu- sion lengths

Results of measurements of the annealing of photodegraded a-Si:H p-i-n solar cells are presented. Although the annealing behavior cannot be described by simple exponential kinetics, it can be characterized by a single activation energy of 1.2 eV. The degradation temperature does not affect this activation energy, although the shape of the annealing curve ...

A Cu alloy/Cu alloy oxide bilayer structure was formed on an n +-a-Si:H substrate using a single Cu alloy target. It was employed for the source/drain electrodes in the fabrication of a-Si:H thin-film transistors with good electrical performance, high thermal stability, and good adhesion. Transmission electron ...

The investigation of amorphous silicon materials at MTSEC has had two major thrusts: (1) to improve the amorphous material, i.e., obtain a low state density in the gap, improve the carrier collection depth and diminish non-radiative recombinations; and (2) to attempt to understand and improve on the limitations of the junction devices while evaluating the amorphous silicon materials. In the first ...

In this paper we describe the fabrication of amorphous SiC:H materials and using them as photoelectrodes in photoelectrochemical cells (PEC). With the increase of CH4 flow (in SiH4 gas mixture) during growth, the bandgap, Eg, increases from ~ 1.8eV to ~2.0eV, while the photoconductivity decreases from ~10-5 S/cm to ~10-8 S/cm. These high-quality a-SiC:H materials with Eg of ...

... FILMS), (*SOLAR CELLS, MANUFACTURING, GALLIUM ALLOYS, ARSENIC ALLOYS, PLATINUM, OXIDES, TRANSPORT PROPERTIES ...

Light trapping in ultrathin plasmonic solar cells Vivian E. Ferry,1,2,* Marc A. Verschuuren,3, and measurement of ultrathin film a-Si:H solar cells with nanostructured plasmonic back contacts, which of optimized, non-random nanostructured back reflectors for thin film solar cells. �2010 Optical Society

The known properties of nitrogen as an impurity in, and as an alloy element of, the germanium network are reviewed in this article. Amorphous and crystalline germanium-nitrogen alloys are interesting materials with potential applications for protective coatings and window layers for solar conversion devices. They may also act as ...

We present temperature-dependent measurements of I-V curves in the dark and under illumination in order to elucidate the dominant transport mechanisms in amorphous silicon-crystalline silicon (a-Si:H/c-Si) heterojunction solar cells. ZnO:Al/(p)a-Si:H/(n)c-Si/(n+)a-Si:H cells are compared with inversely doped structures and the impact ...

Thin hydrogenated amorphous silicon (a-Si:H) layers deposited by hot-wire chemical vapor deposition (HWCVD) are used as both emitters and back contacts in silicon heterojunction solar cells. Low interface recombination velocity and high open-circuit voltage are achieved by a low substrate temperature (200 deg C) which appears to improve dopant activation. ...

We investigate resistive losses at p-type crystalline Si/hydrogen passivated Si:H/ZnO:Al heterojunction back contacts for high efficiency silicon solar cells. A low tunneling resistance for the (p-type) Si:H/(n-type) ZnO part of the junction requires deposition of Si:H with a high hydrogen dilution rate RH>40 resulting in a highly doped microcrystalline (?c) Si:H layer. ...

Significant progress has been made recently at ECD (Energy Conversion Devices, Inc.), in developing new manufacturing technologies for a-Si (amorphous silicon) photovoltaics. In a 2 MW continuous roll-to-roll a-Si PV (photovoltaics) manufacturing plant, designed and constructed by ECD, we have advanced ECD's PV technology and demonstrated the manufacturing of 4 ft2 PV modules ...

Significant progress has been made recently at ECD (Energy Conversion Devices, Inc.), in developing new manufacturing technologies for a-Si (amorphous silicon) photovoltaics. In a 2 MW continuous roll-to-roll a-Si PV (photovoltaics) manufacturing plant, designed and constructed by ECD, we have advanced ECD{close_quote}s PV technology and demonstrated the manufacturing of 4 ...

Objective is to obtain a comprehensive understanding of structure and electronic properties of a-Si:H as they apply to solar cells. First observations were of light enhancement and field suppression of H diffusion in a-Si:H. Theoretical studies were made of hydrogen density of states distribution and its relation to defect metastability. Reduced density of light induced defect ...

Objective is to obtain a comprehensive understanding of structure and electronic properties of a-Si:H as they apply to solar cells. First observations were of light enhancement and field suppression of H diffusion in a-Si:H. Theoretical studies were made of hydrogen density of states distribution and its relation to defect metastability. Reduced density of light induced defect ...

This summary describes tasks of novel improved intrinsic materials for multijunction solar cells, insights into improved stability in materials and solar cells, optimization of solar cell performance with improved intrinsic layers, and optimization of multijunction solar cells. The report characterizes a ...

The principal objective of this program is to conduct research on semiconductor materials and non-semiconductor materials to enhance the performance of multibandgap, multijunction, large-area amorphous silicon-based alloy modules. The goal for this program is to demonstrate stabilized module efficiency of 12% for multijunction modules of area greater than 900 cm(sup 2). ...

The bonded hydrogen on the growing surface of hydrogenated amorphous silicon germanium (a-SiGe:H) alloy films has been investigated by use of infrared reflection absorption spectroscopy (IR-RAS). When the alloy films are Si-rich, the surface hydrogen bonded to Si atoms is found to behave in a similar way to those on the hydrogenated ...

Hydrogenated amorphous silicon-carbon alloys ({ital a}-SiC:H) with band gaps around 1.9 eV have been prepared using trisilylmethane (TSM) as the carbon source by plasma-enhanced chemical vapor deposition. Compared to {ital a}-SiC:H alloys prepared from the conventional CH{sub 4}/SiH{sub 4} mixture, the TSM-based ...

ECD has made important progress in the development of materials, device designs, and manufacturing processes required for the continued advancement of practical photovoltaic technology{sub 1-23}. ECD has pioneered and continues further development of two key proprietary technologies, with significant potential for achieving the cost goals necessary for widespread growth of the photovoltaic market: ...

We improve narrow-bandgap (1.2< ETauc< 1.3 eV) amorphous silicon germanium (a-Si1-xGex:H) alloys grown by hot-wire chemical vapor deposition (HWCVD) by lowering both substrate and filament temperatures. We grew two series of films using a tungsten filament. First we systematically varied the filament temperature (Tf) from our standard temperature of ...

The photoconductance decay (PCD) measurement is a fast and simple method to characterize amorphous/crystalline (a-Si:H/c-Si) silicon interfaces for high-efficiency solar cells. However, PCD only yields information concerning the overall recombination rate in the structure. To overcome this limitation, we have developed and validated a computer-aided PCD ...

Amorphous silicon alloy based triple junction 0.1 m[sup 2] modules with initial efficiencies greater than 11% have been produced using manufacturing equipment. Scale-up of equipment to process substrates 0.56 m[sup 2] in area is nearly complete.

This report describes the research program intended to expand, enhance, and accelerate knowledge and capabilities for developing high-performance, two-terminal multijunction amorphous silicon (a-Si) alloy cells, and modules with low manufacturing cost and...

This report describes research to study the effects of defects, impurities, and interfaces on the performance of photovoltaic (PV) devices, particularly hydrogenated amorphous silicon (a-Si:H) and related alloys. The studies of a SI:H and related alloys i...

This report describes the research performed during Phase I of this three-phase, three-year program. The research program is intended to expand, enhance, and accelerate knowledge and capabilities for developing high-performance, two-terminal multijunction amorphous silicon (a-Si) alloy cells and modules with low manufacturing cost and high reliability. To ...

We report the deposition of improved hydrogenated amorphous silicon germanium (a-SiGe:H) films by the hot wire CVD (HWCVD) technique using a tantalum filament operating at a low temperature. We gauge the material quality of the a-SiGe:H films by comparing infrared, small angle X-ray scattering (SAXS), photocapacitance, and conductivity measurements to earlier results, and ...

Solarex, a business unit of Amoco/Enron Solar, is scaling up its a-Si:H/a-SiGe:H tandem device technology for the production of 8 ft2 modules. The current R&D effort is focused on improving the performance, reliability and cost-effectiveness of the tandem junction technology by systematically optimizing the materials and interfaces in small-area ...

Radio frequency glow discharge may be used to deposit films of amorphous silicon from silane gas. It is also possible to dope such films by including traces of diborane or phosphine in the silane gas. Rf sputtering has also been used. This paper intends to study the rectification property of P/undoped a-Si junction. This is particularly important for applications such as a ...

Experimental and theoretical investigations of the growth and properties of doped hydrogenated amorphous silicon (a-Si:H) materials were performed. Controlled doping of laser-induced chemical-vapor-deposited (LICVD) a-Si:H, both n-type and p-type, was ach...

This report describes the research on high-efficiency CdTe-based thin-film solar cells and on high-efficiency a-Si-based thin-film solar cells. Implemented a diode-array spectrograph system and used optical emission spectroscopy to help optimize the react...

Dual junction amorphous silicon (a-Si) solar cells produced on polyimide substrate have been selected as the best candidate to produce a lightweight solar array for the PowerSphere program. The PowerSphere concept features a space-inflatable, geodetic sol...

We demonstrated that the remote PECVD process can be used to deposit heavily doped n-type and p-type a-Si:H thin films. We optimized conditions for depositing undoped, near-intrinsic and heavily doped thin films of {mu}c(microcrystalline)-Si by remote PECVD. We extended the remote PECVD process to the deposition of undoped and doped a-Si,C:H and {mu}c-Si,C ...

We demonstrated that the remote PECVD process can be used to deposit heavily doped n-type and p-type a-Si:H thin films. We optimized conditions for depositing undoped, near-intrinsic and heavily doped thin films of [mu]c(microcrystalline)-Si by remote PECVD. We extended the remote PECVD process to the deposition of undoped and doped a-Si,C:H and [mu]c-Si,C ...

The potential pitfalls which may lead to an overestimation of AM-1 short circuit current densities have been investigated for 0.02 cm/sup 2/ a-SiH /SUB x/ solar cell structures. The authors have spatially profiled carrier collection in a-Si PIN solar cells using a scanned 10..mu.. diameter laser beam. The small beam size yields not ...

A new method of maintaining window transparency in photochemical vapor deposition (photo-CVD) has been developed in which the window is continuously etched clean during the deposition process. This technique is demonstrated in the deposition of /ital a/-Si:H(F) by direct photo-CVD of Si/sub 2/H/sub 6/ using XeF/sub 2/ as an etchant. XeF/sub 2/ is also used to clean the chamber ...

This report describes work performed by Pennsylvania State University in collaboration with the NREL Wide-Band-Gap Team. The goal of this team is to develop a single-junction, wide-gap solar cell with good stabilized parameters. The objectives of the subcontract are to (1) develop a cost-effective amorphous silicon PV technology to foster a viable amorphous silicon PV industry ...

Hydrogenated a-Si solar cells were prepared by rf-sputtering. It was found that for a-Si the surface microstructure of sputtered films can be altered by a simple post-deposition etching process and controlled by varying the film preparation conditions. It was demonstrted that such textured surfaces can be advantageous in increasing the efficiency of ...

Photoelectrochemical (PEC) water dissociation into hydrogen and oxygen at a semiconductor-liquid interface offers an environmentally benign approach to hydrogen production. We have developed an integrated PEC device using hydrogenated amorphous silicon carbide (a-SiC or a-SiC:H) material as photoelectrode in conjunction with an amorphous silicon (a-Si) ...

A solar cell array comprising a plurality of solar cells connected together by electrical contact means comprising amorphous metal alloy conductors.

This dissertation summarizes the research work on the investigation and optimization of high efficiency hydrogenated amorphous silicon (a-Si:H) based thin film n-i-p single-junction and multi-junction solar cells, deposited using radio frequency (RF) and very high frequency (VHF) plasma enhanced chemical vapor deposition (PECVD) techniques. The fabrication ...

Under this four-year PV:BONUS Program, ECD and United Solar are developing and demonstrating two new lightweight flexible building integrated Photovoltaic (BIPV) modules specifically designed as exact replacements for conventional asphalt shingles and standing seam metal roofing. These modules can be economically and aesthetically integrated into new residential and commercial ...

A new tunnel recombination junction is fabricated for n�i�p type micromorph tandem solar cells. We insert a thin heavily doped hydrogenated amorphous silicon (a-Si:H) p+ recombination layer between the n a-Si:H and the p hydrogenated nanocrystalline silicon (nc-Si:H) layers to improve the performance of the n�i�p tandem ...

We investigate the performance of a single-junction amorphous Si (a-Si) solar cell fabricated with inductively coupled plasma (ICP) deposition technique. The high-density plasma resulting from high dissociation capacity of ICP enables good-quality hydrogenated Si films to be synthesized at low temperatures. High-density ICP also promotes the diffusion of ...

United Solar Ovonic is world's largest manufacturer of thin film solar laminates that convert sunlight to electricity. In 1997, we attained initial 14.6% and stable 13.0% cell efficiencies using an a-Si:H/a-SiGe:H/a-SiGe:H triple-junction structure, which established the foundation of large volume roll-to-roll production. Since then, the power rating of ...

ABSTRACT: Conductive-probe atomic force microscopy (CP-AFM) measurements reveal the existence of a conductive channel at the interface between p-type hydrogenated amorphous silicon (a-Si:H) and n-type crystalline silicon (c-Si) as well as at the interface between n-type a-Si:H and p-type c-Si. This is in good agreement with planar conductance measurements ...

Conductive-probe atomic force microscopy (CP-AFM) measurements reveal the existence of a conductive channel at the interface between p-type hydrogenated amorphous silicon ( a-Si:H) and n-type crystalline silicon ( c-Si) as well as at the interface between n-type a-Si:H and p-type c-Si. This is in good agreement with planar conductance measurements that ...

Advances in the science and technology of hydrogenated amorphous silicon (a-Si:H, also referred to as a-Si) and the associated devices including thin-film transistors (TFT) during the past three decades have had a profound impact on the development and commercialization of major applications such as thin-film solar cells, digital image scanners and X-ray ...

This report describes results achieved during the second phase of a four year subcontract to develop and understand thin film solar cell technology related to a-Si and its alloys, CuIn{sub 1{minus}x}Ga{sub x}Se{sub 2}, and CdTe. Accomplishments during this phase include, development of equations and reaction rates for the formation of CuIn{sub ...

This report describes research focused on improving the individual component cells from which the multijunction devices are fabricated. The Mid-Bandgap and Metastability subteam and the Low-Bandgap subteam have the responsibility to develop appropriate materials for the respective layer of the triple-junction solar cell. To this end, it is necessary to characterize the ...

Transport properties are very important for solar cells. The efficiency of solar cells is determined by the competition of carrier collection and recombination. The most important parameter is the carrier mobility-lifetime product. However, methods commonly used for measuring transport parameters require specially designed samples. The results are often ...

In this report, an overview of the recent status of photovoltaic (PV) power generation is first presented from the viewpoint of reducing CO2 emission. Next, the Japanese roadmap for the research and development (R&D) of PV power generation and the progress in the development of various solar cells are explained. In addition, the present status and future prospects of ...

The efficiency of a solar collector is increased by the use of a solar panel having an adherent coating of a comminuted ferroalloy. The ferro-alloy displays a high degree of absorption of solar energy in the visible range and a minimal of infrared radiation.

This paper discusses applications of the tight-binding method to: (i) localized anti-bonding states of Si-H groups in [ital a]-Si:H, and (ii) dangling bond defect states in [ital a]-Si,Ge:H alloys. The [ital a]-Si:H calculations demonstrate that anti-bonding states of Si-H groups with bond-angle distortions of ...

The growth and characterization of hydrogenated amorphous silicon (a-Si:H) and hydrogenated amorphous silicon -carbon (rm a-rm Si _{1-X}C_{X}: H) alloys employing liquid organometallic sources are described. N -type a-Si:H films were grown using a mixture of silane and tertiarybutylphosphine (TBP-rm C_4H _9P_2) vapor in a plasma ...

We have improved the quality of our narrow-bandgap a-SiGe:H grown by hot-wire chemical vapor deposition (HWCVD) by decreasing our W filament diameter and our substrate temperature. We now grow a-SiGe:H with Tauc bandgaps below 1.5 eV, having a photoresponse equal to or better than our plasma-enhanced CVD-grown alloys. We enhanced the ...

Thin ({approximately}1,000 {angstrom}) semiconducting films of hydrogenated amorphous silicon (a-Si:H) and its carbon alloy (a-Si:C:H) were applied to microstrip gas chambers in order to control gain instabilities due to charges in or on the substrate. The light sensitivity, which is defined as the ratio of light-to-dark conductivity, ...

In this report we present the results for the four principal tasks of this research project: Amorphous Silicon Solar Cell Characteristics and Modeling; Photocarrier Drift Mobility Measurements in hydrogenated amorphous silicon (a-Si:H), microcrystalline s...

This paper describes the effect of doping boron atoms to the intrinsic (i-) layer on the stability of metal/n-i-p/ITO amorphous silicon solar cells. The stability is improved as the amount of doped boron atoms increases. We have explained the improvement in cell performance and its stability by the counterdoping of phosphorus with boron on the basis of the photo-induced change ...

This report summarizes the results of recent a-Si:H thin-film photovoltaic (PV) materials research. The work reported here concerned the fabrication of a-Si:H solar cells at high deposition rates using disilane. This task required the construction of a ne...

Current generation in hydrogenated amorphous silicon, a-Si(H), was found to be predominately from the space-charge region. The mobility-lifetime (..mu..tau) products were the order of 5 x 10/sup -10/ cm/sup 2//V for both holes and electrons. It was necessary to consider trapping and recombination of the optically generated carriers in the space charge region to interpret ...

A detailed study of the photoluminescence, photoconductivity, and infrared absorption of discharge-produced a-Si has shown the optimum substrate temperature to be approx. 300 to 350 exp 0 C. The photovoltaic properties of a-Si solar cells are also optimiz...

The atomic structure and electronic properties of crystalline silicon/hydrogenated amorphous silicon (c-Si/a-Si:H) interfaces in silicon heterojunction (SHJ) solar cells are investigated by high-resolution transmission electron microscopy, atomic-resolution Z-contrast imaging, and electron energy loss spectroscopy. We find that all high-performance SHJ ...

The incorporation of chlorine has a significant effect on the dark conductivity of doped and undoped hydrogenated amorphous silicon (a-Si:H). The dark conductivity of a-Si:H films deposited from dichlorosilane (SiCl{sub 2}H{sub 2}) and SiH{sub 4}, and doped with diborane, increases by as much as a factor of 100 over the usual a-Si:H,B films deposited ...

thin-film solar cell types: hydrogenated amorphous silicon a-Si:H p-i-n cells, organic bulk in organic BHJ solar cells,26 and we suspect it, as well as substrate defects, may be involvedUniversality of non-Ohmic shunt leakage in thin-film solar cells S. Dongaonkar,1,a J. D. Servaites

ULTRA-LIGHTWEIGHT AMORPHOUS SILICON SOLAR CELLS DEPOSITED OIN 7.5pn-1 THICK STAINLESS STEEL of Toledo, Toledo, Ohio 43606 ABSTRACT To significantly reduce the solar cell weight and increase its specific power for space application, we deposited a-Si thin film solar cells on ultra-thin stainless steel

The conversion efficiency of amorphous silicon-hydrogen (a-Si:H) solar cells is limited because the minority-carrier collection length is much shorter than the solar absorption length. To overcome this limitation, a novel cell design is proposed utilizing an a-Si:H active layer less than one collection length thick, which is ...

An experimental and numerical study of a-SiGe:H based solar cells with band gap graded i-layer in the shape of a V is presented. The variation of the location of the band gap minimum has strong influence on the solar cell performance. Comparisons of experimental and simulated data of the dark IV-behavior, IV-curves under illumination and the quantum ...

A research program on hydrogenated amorphous silicon (a-Si:H) and the a-Si:H solar cell is described that includes six research tasks: theoretical modeling, deposition and doping studies, experimental methods for the characterization of a-Si:H, formation of solar-cell structures, theoretical and experimental evaluation of ...

We have studied solar water splitting with a composite semiconductor electrode, composed of an n-i-p junction amorphous silicon (a-Si, Eg? 1.7 eV) layer, an indium tin oxide (ITO) layer, and a tungsten trioxide (WO3, Eg 2.8 eV) particulate layer. The n-i-p a-Si layer, which had more accurately a structure of n-type microcrystalline ( ...

Intrinsic a-Si:H thin films, which can have passivation functions on the surface of crystalline Si, were deposited by inductively coupled plasma chemical vapor deposition (ICP-CVD). The properties of the films were investigated at deposition temperatures ranging from 50 to 400 degrees C. The Si--H stretching mode at 2000 cm(-1), which indicates good film quality, was found in ...

We present femtosecond studies of photoexcited carrier dynamics in hydrogenated amorphous silicon and silicon-germanium alloys grown by the hot-wire assisted chemical vapor deposition (HWCVD) technique, which is promising for producing high-quality device-grade materials.

fractions of 0, 15, 29, 47, 63, 81, and 100at.% were obtained from Yueqin Xu and Harv Mahan at NREL. These 1.2 to 1.6 micron thick alloy films were deposited onto n + a-Si:H...

to further improve the economies of scale which are inherent in ECD's continuous roil-to-roll amorphous--a significant problem in many glass substrate amorphous silicon alloy PV module manufacturing plants. ECD manufacturing. As a result, capital equipment costs for a large volume plant utilizing ECD's roll