Proton irradiation effects on InP solar cells fabricated from LEC-grown single crystals

Abstract

Abstract Proton-irradiation effects on InP solar cells fabricated from LEC- (liquid encapsulated Czochralski) grown single crystals have been studied. Moreover, the defect behavior for proton-irradiated InP single crystals has also been analyzed using the DLTS (deep-level transient spectroscopy) method. The energy dependence of the proton damage in InP crystals and solar cells has been clarified. The origins of the defect centers induced by proton irradiation have been considered. In the case of high-energy proton irradiation above 7 MeV, the major defect centers in InP are thought to be due to phosphorus-related defects. In the case of low-energy proton irradiation below 5 MeV, the origins of the major defect centers that act as recombination centers are speculated to be due to complex defects such as vacancy-impurity complexes and multi-vacancies. Superior resistance to high-energy (above 0.5 MeV) proton irradiation of InP solar cells compared to Si and GaAs cells is confirmed. The proton damage to InP solar cells has also been analyzed using defect center data based on DLTS analysis.