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Phase II Final Project Report SBIR Project: "A High Efficiency PV to Hydrogen Energy System"

Description: The innovative research conducted for this project contributed greatly to the understanding of generating low-cost hydrogen from solar energy. The project’s research identified two highly leveraging and complementary pathways. The first pathway is to dramatically increase the efficiency of converting sunlight into electricity. Improving solar electric conversion efficiency directly increases hydrogen production. This project produced a world record efficiency for silicon solar cells and contrib… more
Date: September 2, 2008
Creator: Slade, A; Turner, J; Stone, K & McConnell, R
Partner: UNT Libraries Government Documents Department
open access

CPV Cell Infant Mortality Study: Preprint

Description: Six hundred and fifty CPV cells were characterized before packaging and then after a four-hour concentrated on-sun exposure. An observed fielded infant mortality failure rate was reproduced and attributed to epoxy die-attach voiding at the corners of the cells. These voids increase the local thermal resistance allowing thermal runaway to occur under normal operation conditions in otherwise defect-free cells. FEM simulations and experiments support this hypothesis. X-ray transmission imaging of … more
Date: May 1, 2011
Creator: Bosco, N.; Sweet, C.; Silverman, T. & Kurtz, S.
Partner: UNT Libraries Government Documents Department
open access

Upside-Down Solar Cell Achieves Record Efficiencies (Fact Sheet)

Description: The inverted metamorphic multijunction (IMM) solar cell is an exercise in efficient innovation - literally, as the technology boasted the highest demonstrated efficiency for converting sunlight into electrical energy at its debut in 2005. Scientists at the National Renewable Energy Laboratory (NREL) inverted the conventional photovoltaic (PV) structure to revolutionary effect, achieving solar conversion efficiencies of 33.8% and 40.8% under one-sun and concentrated conditions, respectively.
Date: December 1, 2010
Partner: UNT Libraries Government Documents Department
open access

Phase Separation and Facet Formation during the Growth of (GaAs)1-x(Ge2)x Alloy Layers by Metal Organic Vapour Phase Epitaxy

Description: Metal organic vapour phase epitaxy (GaAs)1-x(Ge2)x alloy layers, 0<x<0.22, were grown at temperatures between 640 and 690 C, on vicinal (001) GaAs substrates. Phase separation occurred in all the layers. The phase-separated microstructure changed with alloy composition, growth temperature, and substrate orientation. In x {approx} 0.1 layers grown at 640 C, Ge segregation occurred on {l_brace}115{r_brace}B planes associated with a {l_brace}115{r_brace}B surface faceting. Increase in growth… more
Date: September 13, 1999
Creator: Norman, A. G.; Olson, J. M.; Geisz, J. F.; Moutinho, H. R.; Mason, A.; Al-Jassim, M. M. et al.
Partner: UNT Libraries Government Documents Department
open access

Amorphous silicon research. Final technical progress report, 1 August 1994--28 February 1998

Description: 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 pressure, rf power, and hydrogen dilution were investigated. United Solar carried out a series of experiments using discharge modulation at various p… more
Date: May 1, 1998
Creator: Guha, S.
Partner: UNT Libraries Government Documents Department
open access

NREL Scientists Spurred the Success of Multijunction Solar Cells (Fact Sheet)

Description: Before 1984, many scientists believed that high-quality gallium indium phosphide (GaInP) alloys could not be grown for use as semiconductors because the alloys would separate. One researcher at the Solar Energy Research Institute (SERI) thought differently. His name was Jerry Olson, and his innovative thinking changed solar history. Olson identified a material combination that allowed the multijunction cell to flourish. It is now the workhorse that powers satellites and the catalyst for renewed… more
Date: September 1, 2012
Partner: UNT Libraries Government Documents Department
open access

Low-Cost High-Concentration Photovoltaic Systems for Utility Power Generation

Description: Under DOE's Technology Pathway Partnership (TPP) program, Amonix, Inc. developed a new generation of high-concentration photovoltaic systems using multijunction technology and established the manufacturing capacity needed to supply multi-megawatt power plants buing using the new Amonix 7700-series solar energy systems. For this effort, Amonix Collaborated with a variety of suppliers and partners to complete project tasks. Subcontractors included: Evonik/Cyro; Hitek; the National Renewable Energ… more
Date: March 31, 2012
Creator: McConnell, R.; Garboushian, V.; Gordon, R.; Dutra, D.; Kinsey, G.; Geer, S. et al.
Partner: UNT Libraries Government Documents Department
open access

Inverted Metamorphic Multijunction (IMM) Cell Processing Instructions

Description: This technical report details the processing schedule used to fabricate Inverted Metamorphic Multijunction (IMM) concentrator solar cells at The National Renewable Energy Laboratory (NREL). These devices are used as experimental test structures to support the research at NREL that is focused on increasing the efficiency of photovoltaic power conversion. They are not intended to be devices suitable for deployment in working concentrator systems primarily because of heat sinking issues. The proce… more
Date: February 1, 2012
Creator: Duda, A.; Ward, S. & Young, M.
Partner: UNT Libraries Government Documents Department
open access

III-V Growth on Silicon Toward a Multijunction Cell

Description: A III-V on Si multijunction solar cell promises high efficiency at relatively low cost. The challenges to epitaxial growth of high-quality III-Vs on Si, though, are extensive. Lattice-matched (LM) dilute-nitride GaNPAs solar cells have been grown on Si, but their performance is limited by defects related to the nitrogen. Advances in the growth of lattice-mismatched (LMM) materials make more traditional III-Vs, such as GaInP and GaAsP, very attractive for use in multijunction solar cells on sili… more
Date: November 1, 2005
Creator: Geisz, J.; Olson, J.; McMahon, W.; Friedman, D.; Kibbler, A.; Kramer, C. et al.
Partner: UNT Libraries Government Documents Department
open access

Performance of MicroLink Cells Developed Under Navy STTR: Cooperative Research and Development Final Report, CRADA Number CRD-11-426

Description: Evaluate MicroLink cells as a function of temperature and spectral irradiance following the teams' standard procedures. These measurements will include the standard procedures for evaluating multijunction cells including quantum efficiency measurements and current versus voltage measurements.
Date: June 1, 2013
Creator: Emery, K.
Partner: UNT Libraries Government Documents Department
open access

Polycrystalline Thin-Film Multijunction Solar Cells

Description: We present a digest of our research on the thin-film material components that comprise the top and bottom cells of three different material systems and the tandem devices constructed from them.
Date: November 1, 2005
Creator: Noufi, R.; Wu, X.; Abu-Shama, J.; Ramanathan, K; Dhere, R.; Zhou, J. et al.
Partner: UNT Libraries Government Documents Department

Technology Overview: Concentrator PV 2010 Boot Camp (CPV)

Description: The presentation introduces the various types of CPV technologies and provides a status report of today's CPV companies. Six different architectures of multijunction cells are shown to near or surpass 40% in efficiency. The design space for CPV is quite complex, which is a curse for those trying to narrow it down for the first prototype, but a blessing for those who want multiple pathways for product improvement in coming years.
Date: October 11, 2010
Creator: Kurtz, S.; Bett, A. & Hartsoch, N.
Partner: UNT Libraries Government Documents Department
open access

Algorithm for Building a Spectrum for NREL's One-Sun Multi-Source Simulator: Preprint

Description: Historically, the tools used at NREL to compensate for the difference between a reference spectrum and a simulator spectrum have been well-matched reference cells and the application of a calculated spectral mismatch correction factor, M. This paper describes the algorithm for adjusting the spectrum of a 9-channel fiber-optic-based solar simulator with a uniform beam size of 9 cm square at 1-sun. The combination of this algorithm and the One-Sun Multi-Source Simulator (OSMSS) hardware reduces N… more
Date: June 1, 2012
Creator: Moriarty, T.; Emery, K. & Jablonski, J.
Partner: UNT Libraries Government Documents Department
open access

NREL Spurred the Success of Multijunction Solar Cells (Fact Sheet)

Description: Many scientists once believed that high-quality gallium indium phosphide (GaInP) alloys could not be grown for use as semiconductors because the alloys would separate. However, researchers at the National Renewable Energy Laboratory (NREL) thought differently, and they employed GaInP in a material combination that allowed the multijunction cell to flourish. The multijunction cell is now the workhorse that powers satellites and the catalyst for renewed interest in concentrator photovoltaic produ… more
Date: August 1, 2013
Partner: UNT Libraries Government Documents Department

High-Efficiency Solar Cells for Large-Scale Electricity Generation & Design Considerations for the Related Optics

Description: The photovoltaic industry has been growing exponentially at an average rate of about 35%/year since 1979. Recently, multijunction concentrator cell efficiencies have surpassed 40%. Combined with concentrating optics, these can be used for electricity generation.
Date: September 17, 2007
Creator: Kurtz, S.; Olson, J.; Geisz, J.; Friedman, D.; McMahon, W.; Ptak, A. et al.
Partner: UNT Libraries Government Documents Department
open access

High-Performance Photovoltaic Project: Identifying Critical Pathways; Kickoff Meeting

Description: The High Performance Photovoltaic Project held a Kickoff Meeting in October, 2001. This booklet contains the presentations given by subcontractors and in-house teams at that meeting. The areas of subcontracted research under the HiPer project include Polycrystalline Thin Films and Multijunction Concentrators. The in-house teams in this initiative will focus on three areas: (1) High-Performance Thin-Film Team-leads the investigation of tandem structures and low-flux concentrators, (2) High-Effic… more
Date: November 7, 2001
Creator: Symko-Davis, M.
Partner: UNT Libraries Government Documents Department
open access

Outdoor performance stability and controlled light-soak testing of amorphous silicon multijunction modules at NREL

Description: The National Renewable Energy Laboratory (NREL) has been testing amorphous silicon (a-Si) Photovoltaic (PV) modules for more than a decade. NREL has been conducting controlled light-soak testing of multifunction a-Si modules to characterize their performance for stability evaluation as well as to benchmark the technology status. Some of the test modules, after controlled light-soak testing, have been installed outdoors. The authors have observed that under outdoor exposure, the modules further … more
Date: October 1, 1995
Creator: Mrig, L.; Burdick, J.; Luft, W. & Kroposki, B.
Partner: UNT Libraries Government Documents Department
open access

Technology Pathway Partnership Final Scientific Report

Description: This report covers the scientific progress and results made in the development of high efficiency multijunction solar cells and the light concentrating non-imaging optics for the commercial generation of renewable solar energy. During the contract period the efficiency of the multijunction solar cell was raised from 36.5% to 40% in commercially available fully qualified cells. In addition significant strides were made in automating production process for these cells in order to meet the costs r… more
Date: April 26, 2012
Creator: Hall, John C. Dr. & Godby, Larry A.
Partner: UNT Libraries Government Documents Department
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