Manipulation of Crystallization Kinetics for Perovskite Photovoltaics Prepared Using Two-Step Method

Two-step fabricated perovskite solar cells have attracted considerable attention because of their good reproducibility and controllable crystallization during production. Optimizing the quality of perovskite films plays a decisive role in realizing superb performance via a two-step method. Many breakthroughs have been achieved to obtain high-quality film from the perspective of manipulating crystallization kinetics in the two-step preparation process, which promotes the rapid development of perovskite photovoltaics. Therefore, focusing on the crystallization process in the two-step preparation process can provide a reliable basis for optimizing the performance of two-step devices. In this review, recent progress on regulating the crystallization process for two-step PSCs is systematically reviewed. Firstly, a specific description and discussion are provided on the crystallization process of perovskite in different two-step methods, including spin-coating, immersion and evaporation. Next, to obtain high-quality perovskite film via these two-step methods, current strategies of additive engineering, composition engineering, and solvent engineering for regulating the crystallization process for two-step perovskite are classified and investigated. Lastly, the challenges which hindering the performance of the two-step perovskite photovoltaics and an outlook toward further developments are proposed.