Ferroelectric solar cells based on inorganic–organic hybrid perovskites

Ferroelectric solar cells based on ferroelectric oxides have attracted significant attention owing to many unique advantages, such as the switchable photocurrent and photovoltage, and the above bandgap open circuit voltages. However, the small photocurrent densities of the typical ferroelectric solar cells greatly limit their photovoltaic performance. In this report, we experimentally revealed the polarization switching properties of inorganic–organic hybrid perovskites and developed ferroelectric solar cells based on the hybrid perovskites. Hybrid perovskite methylammonium lead trihalide (MAPbX3) thin films exhibited 180 domain phase switching and polarization hysteresis loops. Ferroelectric solar cells based on the mixed halide MAPbI3 xClx thin film demonstrate a power conversion efficiency of 6.7% and the ferroelectric solar cells display switchable photovoltaic effects. This work provides an alternative but exhilarating solution for highperformance ferroelectric solar cells beyond inorganic ferroelectric oxides.