Photoluminescence characteristics of InGaP/GaAs dual-junction solar cells under current mismatch conditions.

Current mismatch is a critical factor for impairing the conversion efficiency of multi-junction solar cells. Herein, we find a visual phenomenon to distinguish whether the InGaP/GaAs dual-junction solar cell is undergoing current mismatch. It is found that the device at short circuit emits red light under the multiple-source solar simulator when the incident power of the first light source is high. Furthermore, the similar photoluminescence characteristic is also observed when two different lasers are used. These results exhibit that the photoluminescence phenomenon is a facile method to identify the current mismatch of multi-junction solar cells. [ABSTRACT FROM AUTHOR]