Flexible thin film photovoltaics offer a number of advantages over single crystal technologies for space power. Such advantages include a large number of watts per kilogram and watts per volume, superior radiation resistance, low cost, and good temperature cycle stability. However, thin film photovoltaics on lightweight flexible substrates is not yet a mature technology. The use of non-glass substrates poses several challenges, including the requirement of modified scribing techniques due to the thin opaque substrate, differing film growth due to lack of Na from the glass, and possibly limits on the process temperature if polymer substrates are used. Materials Research Group, Inc. (MRG, Inc.) proposes the development of thin-film polycrystalline Culn(sub x)Ga(sub 1-x)Se(sub 2) (CIGS) modules on stainless steel substrates to best provide the advantages listed above. CIGS photovoltaic devices on thin steel foil substrates provide excellent potential for high efficiency compared to other absorber materials, the ability to deposit high-quality material in high-temperature deposition steps, adequate tensile strength, demonstrated radiation hardness, a weight per area close to that of polymer substrates and far superior to that of crystalline cells, and the feasibility of simple external interconnects.
Keywords: SPACEFLEXIBLE MODULE THIN FILM PHOTOVOLTAICS COPPER INDIUM DISELENIDE POWER
