Abstract All-inorganic lead halide perovskite nanocrystals exhibit excellent optical properties, which make them promising for optoelectronic devices. However, the insulating organic ligands at the nanocrystals’ surface represent a major issue in their effective application in devices. To decrease the effect of the ligands on carrier transport in perovskite nanocrystal-based films, several post synthesis treatment methods have been reported, but in most of the cases the nanocrystals tend to degrade over long term storage. To address these concerns, herein we develop a novel surface treatment procedure based on the combination of ammonium thiocyanate and benzoyl bromide for CsPbBr3 nanocrystals. The morphological, optical and structural characterizations were carried out to investigate the evolution of both as-prepared and surface-treated nanocrystals in spin coated films, over aging under ambient conditions. It was found that films based on the treated nanocrystals present higher stability, providing a promising path for fabricating optoelectronic devices based on these materials.

中文翻译：

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CsPbBr3 纳米晶薄膜的长期光学和形态稳定性

摘要 全无机卤化铅钙钛矿纳米晶体具有优异的光学性能，使其有望用于光电器件。然而，纳米晶体表面的绝缘有机配体是其在器件中有效应用的一个主要问题。为了减少配体对钙钛矿纳米晶体薄膜中载流子传输的影响，已经报道了几种合成后处理方法，但在大多数情况下，纳米晶体在长期储存后往往会降解。为了解决这些问题，我们在本文中开发了一种基于硫氰酸铵和苯甲酰溴的组合用于 CsPbBr3 纳米晶体的新型表面处理程序。形态学上，进行了光学和结构表征以研究旋涂薄膜中制备的和表面处理的纳米晶体在环境条件下老化的演变。结果表明，基于处理过的纳米晶体的薄膜具有更高的稳定性，为制造基于这些材料的光电器件提供了有希望的途径。