Advanced space solar cells

This paper will present a brief overview of the status of research and development of advanced space solar cells from a variety of materials. Most of the investigations at present are focused on binary, ternary and quaternary III–V semiconducting compounds such as InP, GaInAs and GaInP 2 . Growth techniques used for producing laboratory cells include liquid‐phase epitaxy (LPE), organometallic vapor phase epitaxy (OMVPE), molecular beam epitaxy (MBE) or any of a number of variations of these techniques, such as atomic layer epitaxy (ALE), etc. Gallium arsenide is at present the only commercially available III–V compound solar cell. Compound III–V multiple bandgap cells are now under development in a jointly sponsored NASA/Air Force manufacturing technology demonstration program. In general, the decision to use a particular cell technology in space is determined by several factors, emphasis on any particular one depending on the mission environment: some are related to the properties of the photovoltaic material itself, such as efficiency and resistance to radiation damage, and some are related to details of the cell structure and associated materials, such as survivability under repeated thermal cycling and resistance to atomic oxygen erosion. The impact of these requirements on cell material selection and structural design is briefly discussed. This paper was produced under the auspices of the US Government and is therefore not subject to copyright in the USA