Effect of 150 keV proton irradiation on the performance of GaAs solar cells

Abstract

In this paper, the effects of a 150 keV proton radiation on a GaAs sub-cell of GaInP/GaAs/Ge trip junction solar cells and its radiation damage were studied. The degradation behavior of the solar cells was analyzed by theoretical device modeling combined with electro-optical characterization techniques such as external quantum efficiency, IV measurements, and photoluminescence (PL). The degradation of cell output parameters by protons was plotted as a function of the displacement damage dose. The results show that the short-circuit currents degrades less than open-circuit voltages because the base region of GaAs is severely damaged. The PL results indicated that proton irradiation exerted destructive effect on the photoelectric properties of the material. Such destructiveness was due to the numerous defects introduced by proton irradiation, which destroys the integrity of the lattice space, resulting in a decrease in the diffusion length of the minority and an increase in the surface recombination velocity. By COMSOL simulation analysis, it is found that the reason of radiation degradation of GaAs is the decrease of minority carrier time after irradiation and simulation results show that the PL results are in good agreement with the simulation results which can provide a method for the calculation of internal defects and minority carriers in multi-junction solar cells.