Heteroepitaxially grown InP solar cells

The properties of InP solar cells, processed by OMCVD on silicon substrates with an intermediate GaAs layer (InP/GaAs/Si) and on GaAs substrates (InP/GaAs), were determined before and after irradiation with 10-MeV protons. The preirradiation transport properties were found to be influenced largely by dislocations occurring at the InP-GaAs interface. A carrier removal rate of 1.8*10/sup 3/ cm/sup -1/ was observed after irradiation to a proton fluence of 1.1*10/sup 13/ cm/sup -2/. Despite the high degree of defect generation, the radiation resistance, of the heteroepitaxial cells was considerably greater than that observed for monolithic n/sup +/p InP cells. The observed low cell efficiencies and high radiation resistance are attributed to the dominant effect of dislocations in the cell's p-base region. >