Electroluminescence analysis of VOC degradation of individual subcell in GaInP/GaAs/Ge space solar cells irradiated by 1.0 MeV electrons

Abstract The open-circuit voltage (VOC) degradation for individual subcell in 1.0 MeV electrons-irradiated GaInP/GaAs/Ge solar cells has been analyzed using electroluminescence (EL) measurements. By using the relationship between VOC degradation and electron fluence, the capture cross section of the defects induced by electron irradiation in individual subcells were determined. Furthermore, by comparing the thermal activation energy and capture cross section, a defect located at Ev+0.55 eV styled H2 hole trap is nonradiative recombination center in GaInP subcell, a defect located at EC-0.96 eV styled E5 electron trap is nonradiative recombination center in GaAs subcell, and a defect located at EC-0.38 eV styled E-center electron trap is nonradiative recombination center in Ge subcell.