In-situ measurement of degradation of Cu(In,Ga)Se2 thin film solar cells during electron and proton irradiations

Observation of illumination-enhanced annealing of radiation damage to CIGS thin-film solar cells has been reported. In-situ measurements of short circuit current and open circuit voltage of CIGS cells during and after electron and proton irradiations under the short-circuit condition have been carried out in this study. The annealing rates of proton-induced defects in the solar cells under the AM0 solar simulator illumination and short-circuit condition is found to be enhanced compared to that under dark condition. The activation energy of proton-induced defects in CIGS solar cells with and without the AM0 illumination is 0.8 eV and 0.92 eV, respectively, which implies enhancement of defect annealing rates in CIGS thin-film solar cells for minority-carrier injection. Very high annealing rates of electron-induced defects are also obtained. These results suggest that CIGS cells have desirable potential for space applications.