Research towards a 35% efficient concentrator solar cell using III--V compounds. Progress report No. 1, 3 September--3 June 1977. [AlGaAs/GaAs/InP/InGaAs and AlGaAs/GaAs/Ge solar cells]
This report deals with research and development on materials pertinent to the multigap approach to high efficiency solar cells. Initial investigations were confined to the two-gap version, and most of the work was concerned with the InGaAs (0.73 eV) and Ge (0.67 eV) semiconductors that potentially could be used as a lower junction cell to capture the radiation passing through an AlGaAs/GaAs (1.425 eV) upper cell. In addition, some work leading to the realization of the optimum bandgap configuration (1.65 and 1.15 eV) for an optimized two-junction tandem solar cell is reported.