Improving the Quality and Luminescence Performance of All‐Inorganic Perovskite Nanomaterials for Light‐Emitting Devices by Surface Engineering

Abstract Lead halide perovskites and their applications in the optoelectronic field have garnered intensive interest over the years. Inorganic perovskites (IHP), though a novel class of material, are considered as one of the most promising optoelectronic materials. These materials are widely used in detectors, solar cells, and other devices, owing to their excellent charge‐transport properties, high defect tolerance, composition‐ and size‐dependent luminescence, narrow emission, and high photoluminescence quantum yield. In recent years, numerous encouraging achievements have been realized, especially in the research of CsPbX 3 (X = Cl, Br, I) nanocrystals (NCs) and surface engineering. Therefore, it is necessary to summarize the principles and effects of these surface engineering optimization methods. It is also important to scientifically guide the applications and promote the development of perovskites more efficiently. Herein, the principles of surface ligands are reviewed, and various surface treatment methods used in CsPbX 3 NCs as well as quantum‐dot light‐emitting diodes are presented. Finally, a brief outlook on CsPbX 3 NC surface engineering is offered, illustrating the present challenges and the direction in which future investigations are intended to obtain high‐quality CsPbX 3 NCs that can be utilized in more applications.