Photoconverter heating by incident radiation: Overheat temperature and IV-curve correction

The paper completes the study of the photoconverter overheating during IV-curve recording on the pulse simulator of solar radiation. It is experimentally found that after switching on the pulse of light photoconverter voltage decreases linearly with time. The voltage decrease rate proportionally depends on photogenerated current. It has been theoretically shown that such a proportionally is associated with the fact that temperature coefficient α =ΔV/ΔT (V – voltage, T - temperature) depends weakly on the photogenerated current. In using this fact, a method for obtaining isothermal IV-curves was developed. The method is applied to triple-junction GainP/GaAs/Ge solar cell IV-curves. It is shown that the overheating effect can be neglected at the sun concentration ratio less 500 suns (photogenerated current less than 6.5 A/cm2). The p-n junction overheating temperature was also determined.