Gallium-arsenide cell

Photovoltaic (PV) solar cells, which convert incident solar radiation directly into electrical energy, today represent the most common power source for Earth-orbiting spacecraft, such as the International Space Station, where a photovoltaic engineering testbed (PET) is actually assembled on the express pallet. The solid-state photovoltaics, based on gallium arsenide, indium phosphide, or silicon, prove capable, even if to different extents and with... 

Parkinson, B.A., Heller, A., and Miller, B., Effects of cations on the performance of the photoanode in the n-gallium arsenide/potassium selenide (K2Se)-potassium diselenide (K2Se2)-potassium hydroxide/carbon semiconductor liquid junction solar cell, /. Electrochem. Soc., 126,954,1979. 

Gallium arsenide altered host resistance in B6C3F1 mice, resulting in increased resistance to infection by Streptococcus pneumoniae and Listeria monocytogenes [18], but increased susceptibility to Staphylococcus aureus [19] and to tumor development by B16F10 melanoma cells [18], However, inhalation exposure to As203 led to increased... 

Gondre-Lewis, T. A. et al., Gallium arsenide exposure impairs splenic B cell accessory function, Int. Immunopharmacol., 3, 403, 2003. 

Recently, polyethylene and Teflon mesh sample holders have been used. A drop of sample is placed on the mesh and spread to a relatively uniform thickness for analysis. These holders can often be rinsed and reused. A very convenient alternative to liquid sample holders is the technique called attenuated total reflection or ATR. The ATR cell is a crystal of gallium arsenide, GaAs and the infrared radiation enters one end of the trapezoidal crystal. With the angles adjusted to obtain total internal reflection, all of the IR radiation passes through the crystal and exits the other end as shown in Fig. 5.14. 

The satellite would need 50 to 100 square kilometers of collector area using 14% efficient monocrystalline silicon solar cells. More expensive triple junction gallium arsenide solar cells with an efficiency of 28% would reduce the collector area by half. In both cases the solar station s structure would be several kilometers wide, making it much larger than most manmade structures on Earth. Building structures of this size in orbit has never been attempted before. 

Gallium arsenide (Ga + As — GaAs) is electroluminscent in infrared hght and is used for telephone equipment, lasers, solar cell, and other electronic devices. 

Ellis AB, Bolts JM, Kaiser SW, Wrighton MS (1977) Study of n-type gallium arsenide- and gallium phosphide-based photoelectrochemical cells. Stabilization by kinetic control and conversion of optical energy into electricity.99 2948-2853... 

Single crystal silicon (sc-Si), polyciystalline silicon (p-Si), and amorphous silicon (a-Si) can all be used to make solar cells, with fabrication cost and device photoconversion efficiencies decreasing as one moves from single-crystal to amorphous materials. Various properties of these materials are summarized in Table 8.1. Other relatively common solar cell materials include gallium arsenide (GaAs), copper indiirm diselenide (CIS), copper indium-gallium... 

Gallium arsenide exhibits semiconductor properties. It is used in transistors, lasers, solar cells and various high-speed microcircuits. 

Tn comparison, p — n homojiinction cells made of more costly semiconductor materials, e.g., indium phosphide. InP, and gallium arsenide, GaAs, which have energy gaps of 1.2-L.4 eV, and maximum theoretical conversion efficiencies of ca 28-30%, depending on the device construction and layering of junctions. 

Gallium arsenide solar cells advanced in the 1980s for space use because they weighed much less than silicon cells of similar output, since GaAs absorbs sunlight much more strongly than silicon. 

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