Tackling the Defects, Stability, and Photoluminescence of CsPbX3 Perovskite Nanocrystals

Defects have always been an integral part of semiconductor crystals, controlling their optical and electronic properties. Even though growing popularity of the CsPbX3 (X = Cl, Br, I, and their mixture) nanocrystals (NCs) in various applications stems from their defect-tolerant nature, the properties, stability, and practical utility of these substances are still very much governed by the defects. A variety of methods, which are halide-specific, have been developed to regulate the activities of the defects for enhancing the photoluminescence and stability of these NCs. In this Perspective, we trace the origin and manifestation of different types of defects in photoluminescence properties and stability of the CsPbX3 NCs, critically examine the rationale of various passivation strategies to obtain an in-depth understanding of the problem, and recommend the most effective strategy to be followed for tackling defects under any given condition.