Recovery of Radiation Degradation in InGaP Solar Cells by Light Soaking

This work reports that InGaP solar cells irradiated with 1-MeV electrons exhibit a significant recovery of the open-circuit voltage after AM0 light soaking. The light-soaking intensity dependence of defect reduction and change in the carrier concentration profile upon light soaking suggests that recombination of photo-generated carriers plays an important role in the recovery. Because 0.2-MeV electrons are only responsible for recoil of phosphorus in InGaP, the absence of correlation between the activation energy for voltage recovery and the electron-irradiation energies of 0.2, 0.4, and 1 MeV implies that annihilation of radiation-induced indium- and gallium-related defects contributes not to the recovery.