Understanding and preventing degradation in perovskite solar panels due to partial shading-induced reverse biasing

Metal halide perovskites are ionic conductors and can undergo oxidation and reduction. Perovskite solar cells often contain metal electrodes that can be oxidized. Redox reactions occur quite rapidly when the cells are operated in reverse bias, which can happen when a shaded cell is forced to match the current of illuminated cells that are connected in series. Shunting typically occurs in reverse bias when silver electrodes are used, but not when transparent conducting oxides or carbon are used. Oxidation of iodide can result in loss of iodine from the perovskite layer, which can also reduce power conversion efficiency. The talk will describe the electrochemical degradation and how feasible it is to protect different types of modules with bypass diodes.