Rugged, Thin GaAs Solar Cell Development

This report describes the phase II efforts in developing high efficiency GaAs-ON-Ge solar cells for enhanced survivability, ruggedness, and reduced weight over conventional devices. This work emphasizes efforts to improve the cell performance from phase I, initial testing of the cells, and fabrication of a module for space flight testing. The specific goals for the program are An Air Mass Zero AM0 conversion efficiency of 18 for beginning- of-life BOL at 27 or - 2 C An AM0 conversion efficiency of 13.5 at 27 or - 2 C after exposure to 5 x 10 to the 15th power MeV electronssq.cm. A cell weight not to exceed 0.05 grams per square centimeter of cell area. Keywords Gallium arsenides Germanium substrates.