Designing Large-Area Single-Crystal Perovskite Solar Cells

Organic–inorganic halide single-crystal perovskite solar cells (PSCs) are promising for higher efficiency and better stability, but their development lags far behind that of their polycrystalline counterparts. In particular, the low efficiency (<5%) of large-area devices makes the development of an alternative perovskite photovoltaic technology challenging. In this Perspective, we highlight that the optimization of crystal growth and reduction of crystal thickness are keys to improving the performance of the large-area single-crystal PSCs. After analyzing the characteristics of perovskite crystal growth methods and efficiency evolution of single-crystal PSCs, we conclude the low efficiency of large-area devices is due to the conflict between low crystal quality and large crystal thickness. Then, we propose methods to grow high-quality perovskite single crystals and a possible strategy to reduce the crystal thickness. Finally, investigation of key factors and exploration of large-area application are suggested to be conducted in parallel for future development of single-crystal PSCs.