Illumination-induced recovery of Cu(In,Ga)Se2 solar cells after high-energy electron irradiation

Cu(In,Ga)Se-2/CdS/ZnO solar cells irradiated with a 1 MeV electron fluence of 10(18) cm(-2) degrade to about 80% of their initial conversion efficiency. Illumination with white light at an intensity of 100 mW cm(-2) for 3 h at room temperature restores more than 90% of the preirradiation efficiency. The healing process is more efficient if the device is kept under open-circuit conditions during illumination than for short-circuit conditions. Injecting minority carriers by voltage bias in the dark, instead of illumination, does not cause enduring device recovery. This behavior of Cu(In,Ga)Se-2 is in contrast to illumination-induced defect healing processes reported for other semiconductor materials, like GaAs, InP, or GaP. (C) 2003 American Institute of Physics.