Author: Rajul H. ParekhPublisher:
ISBN:
Category : Gallium arsenide
Languages : en
Pages : 240
Book Description
Design and Growth of Increased Efficiency Gallium Arsenide Solar Cells for Space
Author: Rajul H. ParekhPublisher:
ISBN:
Category : Gallium arsenide
Languages : en
Pages : 240
Book Description
High Efficiency GaAs Solar Cell Development
Author: S. KamathPublisher:
ISBN:
Category :
Languages : en
Pages : 106
Book Description
The major goals of the High Efficiency Gallium Arsenide (GaAs) Solar Cell program have been met. An AM0 efficiency of 17.5 percent was achieved. During the second phase of the program, was optimized to improve radiation resistance of the cell without loss of efficiency, thus improving the suitability of the cell for space missions.
Monolithic and Mechanical Multijunction Space Solar Cells
Author: Raj K. JainGaAs Solar Cell Radiation Handbook
Author: B. E. AnspaughPublisher:
ISBN:
Category : Solar batteries
Languages : en
Pages :
Book Description
Scientific and Technical Aerospace Reports
Author: High Efficiency Floating Junction GaAs Solar Cell for Space Applications. Phase 1
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 31
Book Description
AstroPower has demonstrated the feasibility of a lightweight, high efficiency GaAs solar cell that will have superior performance characteristics compared to conventional GaAs solar cells in the space environment. The solar cell design consists of a front floating junction that is coupled to a back collecting junction through the injection of minority carriers across a thin base. Performance benefits are enabled by incorporating an all back contact design with the electrostatic bonding technique and the use of multiple active junctions. By using the proper geometrical and electrical considerations, losses associated with grid shading and low energy radiation damage will be minimized. The key results of the Phase I program include demonstration of an 11% efficient (AMO, 1X), 1 sq cm floating junction GaAs solar cell and a 3 micrometers thick GaAs layer electrostatically bonded to high temperature glass capable of surviving process temperatures up to 700 deg C. This ensures stability of the laminate throughout the process sequence and enables numerous potential applications for thin GaAs semiconductor devices. Continuation of process development in Phase II is anticipated to produce, when fully optimized, a radiation resistant solar cell which has been modeled to have an efficiency of 21.9%.
High efficiency thin-film GaAs solar cells
Author: Jet Propulsion Laboratory (U.S.)Publisher:
ISBN:
Category :
Languages : en
Pages : 72
Book Description
Design, Fabrication, and Characterization of Solar Cells for High Temperature and High Radiation Space Applications
Author: Zachary S. BittnerPublisher:
ISBN:
Category : Solar cells
Languages : en
Pages : 198
Book Description
"In this work, novel III-V photovoltaic (PV) materials and device structures are investigated for space applications, specifically for tolerance to thermal effects and ionizing radiation effects. The first focus is on high temperature performance of GaP solar cells and on performance enhancement through the incorporation of InGaP/GaP quantum well structures. Temperature dependent performance of GaP solar cells is modeled and compared to a modeled temperature dependence of GaAs. The temperature model showed that a GaP cell should have a normalized efficiency temperature coefficient of -1.31 *10−3°C−1, while a standard GaAs cell should have a normalized temperature coefficient of -2.23*10−3°C−1, representing a 42% improvement in the temperature stability of efficiency. Both GaP and GaAs solar cells were grown using metal organic vapor phase epitaxy and fabricated into solar cell devices. An assortment of optical and electrical characterization was performed on the solar cells. Finally, GaP solar cell performance was measured in an environment simulating the temperatures and light concentrations seen in sub 1 AU solar orbits, simulating the effects on a solar cell as it approaches the sun. A positive normalized temperature coefficient of 2.78*10−3°C−1 was measured for a GaP solar cell, indicating an increase in performance with increasing temperature. In addition, comparing results of GaP solar cells with and without quantum wells, the device without MQWs had an integrated short circuit current density of 1.85 mA/cm2 while the device containing quantum wells has a short circuit current density of 2.07 mA/cm2 or a 12.4% short circuit current increase over that of the device without quantum wells, showing that quantum wells can be used effectively in increasing the current generation in GaP solar cells. The second focus of this thesis is on the ionizing radiation tolerance of epitaxially lifted off (ELO) InP and InGaAs (lattice-matched to InP) for the purpose of assessing device lifetime in high-radiation Earth orbits. Solar cells are characterized through spectral responsivity as well as illuminated and dark current-voltage (I-V ) measurements before being subjected to exposure to a 5 mCi 210Po alpha source and a 100 mCi 90Sr beta source. Device performance is measured with increasing particle fluences. Previously reported results showed epitaxially grown InP solar cells to generate 76.5% of the beginning-of-life (BOL) maximum power under AM0 at a 1MeV beta fluence of 6*1015 e/cm2. In this study, a degradation to 71.1% unirradiated maximum power was seen at a 1MeV beta fluence of 3.19*1015 e/cm2. This demonstrates that ELO InP cells degrade comparably to bulk InP cells under ionizing radiation. An InGaAs cell was measured under 5.4 M eV alpha radiation and had a 50% BOL performance point at 4.7*109 5.4MeV alpha/cm2. The 50% BOL performance point for an InP cell in the same conditions was 1.9*1010 alpha/cm2, showing similar degradation at 4x the alpha fluence."--Abstract.
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