Impact of AlOx Dielectric Layer on Performance in Two-Dimensional Perovskite Photovoltaic Devices

Metallic electrode interfacial properties have a crucial impact on the performance of photovoltaic devices. The interfacial interactions between electrodes and transport layers are critical for charge separation, transport, and collection. Herein, we investigate the interfacial interaction between the aluminum electrode and 6,6-phenyl-C61-butyric acid methyl ester (PCBM) on the performance in two-dimensional perovskite photovoltaic devices. It is observed that the aluminum oxide dielectric layer formed at the interface of aluminum electrode and PCBM, accumulating charges to achieve a high voltage (>5 V) in two-dimensional perovskite photovoltaic devices. Further regulating the aluminum oxide layer can optimize the device performance (voltage, current density, series resistance, and efficiency). The capacitive effect of the aluminum oxide dielectric layer is responsible for this high voltage response. This work will provide a reference for future research on the electrode/PCBM interface in perovskite photovoltaic devices.