Degradation of InGaN-based solar cells under monochromatic photoexcitation

This paper investigates the degradation of multi-quantum well InGaN solar cells submitted to step-stress experiments in short-circuit condition by using a 405 nm laser diode. The cells show a negligible degradation up to 44 W/cm2, a slight decrease in short circuit current (Isc) at 111 W/cm2, and a moderate variation in the open circuit voltage (Voc). By means of I-V, C-V and EQE measurements we provide experimental evidence that stress induces the creation of deep levels inside the quantum wells, which may increase the defect- related non radiative recombination, thus reducing the short circuit current of the solar cells.