Factors influencing the nucleation and crystal growth of solution-processed organic lead halide perovskites: a review

Lead halide perovskite solar cells (PSCs) with solution processability, low defect concentration, low cost and high output manufacturing have emerged as promising third-generation photovoltaic technologies. After an unprecedented speed of development, the power conversion efficiencies of small-area PSCs have exceeded 25%, and meanwhile large-scale perovskite modules are also on a rapid rise. At this stage, considering the significant progress in the fabrication of perovskite films with controllable morphology and crystallinity, it is necessary to conduct reviews on the updated understandings of the nucleation and crystal growth behaviors of perovskites. This review aims to clarify the related mechanisms of the complex perovskite formation process, and is devoted to giving a timely summary of the recent advances. Strategies for controlling perovskite nucleation and crystal growth are also discussed. (topical review)