Shedding Light on the Moisture Stability of Halide Perovskite Thin Films

To date, remarkable progress has been achieved in the power conversion efficiency of perovskite solar cells (PSCs). Nevertheless, the instability and degradation of PSCs under external stimuli still shadow the prospectus of their commercialization. As a notorious culprit deteriorating the stability of PSCs, moisture-induced degradation is thereby an important aspect. Herein, a comprehensive review of moisture effects on the halide perovskite film, in particular the moisture-induced degradation mechanism and methods toward enhancing the stability, is discussed. In detail, the benefits for perovskite films having a certain amount of water incorporation are elucidated, and the underlying moisture-induced structural degradation and decomposition process of perovskites are summarized. Light is also shed on the methods to enhance the moisture stability of perovskites, particularly a 3D/2D heterostructure. Thereby, this review will enlighten the readers of understanding moisture-induced degradation and the development of stable perovskites.