Perovskite solar cells have surged ahead in efficiency, yet their long-term stability continues to pose significant hurdles. A stressor that remains largely underexplored is the impact of reverse bias voltage. Reverse bias voltages are caused by current mismatches in series-connected cells, often from partial shading. In this study, we examine how measurement conditions, device architecture, and upscaling to modules influence this phenomenon. Through characterization, we reveal that ion migration and shunting are key drivers of performance loss. Our findings highlight the need for standardized testing protocols and propose reverse bias as a useful method for understanding accelerated degradation.
