Organic Passivation‐Enhanced Ferroelectricity in Perovskite Oxide Films

Abstract Perovskite oxides and organic–inorganic halide perovskite materials, with numerous fascinating features, have been subjected to extensive studies. Most of the properties of perovskite materials are dependence on their ferroelectricity that denoted by remanent polarization (P_r). Thus, the increase of P_r in perovskite films is mainly an effort in material physics. At present, commonplace improvement schemes, i.e., controlling material crystallinity, and post‐annealing by using a high‐temperature process, are normally used. However, a simpler and temporal strategy for P_r improvement is always unavailable to perovskite material researchers. In this study, an organic coating layer, low‐temperature, and vacuum‐free strategy is proposed to improve the P_r, directly increasing the P_r from 36 to 56 µC cm⁻². Further study finds that the increased P_r originates from the suppression of the oxygen defects and Ti defects. This organic coating layer strategy for passivating the defects may open a new way for the preparation of higher‐performance and cost‐effective perovskite products, further improving its prospective for application in the electron devices field.