Modulating preferred crystal orientation for efficient and stable perovskite solar cells-From progress to perspectives

The perovskite solar cell (PSC) has been recognized as a promising candidate for the next generation of photovoltaics due to its excellent power conversion efficiency (PCE), potential low cost and straightforward solution preparation processes. With efforts around the world, the PCE of PSCs has reached 25.7%. As the perovskite film is the most important part of a PSC, its quality dramatically affects the efficiency and stability of the PSC. Numerous works have focused on controlling crystallization to realize oriented growth of perovskite films. Particularly, considering the photoelectric anisotropy of perovskite materials, it is very meaningful to investigate the relationship between preferred crystal orientation and device efficiency and stability. This review highlights various approaches for realizing preferred crystal orientation of polycrystalline perovskite films, including optimizing the perovskite precursor solution and film annealing process, additive engineering, and interface engineering. Furthermore, the key factors affecting oriented crystal growth are carefully discussed, which provides effective guidance to obtain highly-oriented perovskite films for highly efficient and stable PSCs.