Improvement of Photoluminescence and Achieving the Stabilization of Cesium Lead Halide Perovskite Nanocrystals for Lightemitting applications

Abstract

Cesium lead halide (CsPbX3) perovskite nanocrystals (NCs) are of great interest for newlinefuture- generation optoelectronics because of its excellent optical properties and newlineexceptional colour tunability. Nevertheless, these materials suffer degradation which has newlinebecome a major challenge for its utility in practical applications. Researchers mainly newlinefocus on developing various approaches to boost up the photoluminescence properties newlineand stability of CsPbX3 perovskite NCs. To achieve the goal, it is important to understand newlinethe role of surface passivation in the enhancement of photoluminescence properties and newlinestability of CsPbX3 (X=Cl, Br, and I) perovskite nanocrystals. Surface treatment is a newlinesimple and efficient approach for achieving defect-free crystal by stripping off the defect newlinecentres using suitable surface capping ligands. In most of the cases, the stability of newlineCsPbX3 perovskite NCs is largely affected by the halide vacancies and under coordinated newlinelead atoms. These vacancies are prone to external oxidation and moisture which are newlineeventually responsible for degradation of NCs and reduced device performance. This newlinechallenge is well handled by introducing halide-rich conditions during the synthesis of newlineCsPbX3 NCs. On the other hand, the high dynamic nature of conventional ligands oleic newlineacid and oleyamine imparts the destabilization of NCs in a long run. The implementation newlineof various kinds of surface capping ligands via post-treatment or simple in-situ addition newlinecan be a simple and effective strategy for improving the optical properties of perovksite newlineNCs. CsPbBr3 NCs, being the most explored and stable among metal halide perovskite newlineNCs, of near-unity PLQY could be achieved through simple strategies. But, the newlinechallenges pertaining to the stability and achieving near-unity PLQY of the other halide newlinevariants, CsPbCl3, and CsPbI3 perovskite NCs need to be explored. Further studies in newlineterms of achieving better charge transport properties and carrier injection is requisite for newlineachieving better device performances. newline