We present a method to synthesize stable and uniform high-quality perovskite nanocrystals (PNCs) by using excess halide to recover surface defects in CsPbBr₃/ZnS core/shell nanocrystals. Use of N-bromosuccinimide as a halide donor recovered surface halide vacancies of bare CsPbBr₃ PNCs during the growth of the ZnS shell, as confirmed by DFT calculations. This approach achieves a high photoluminescence quantum yield of nearly 1, and significantly increases the stability of PNCs under adverse conditions such as high humidity and elevated temperature. CsPbBr₃/ZnS PNC light-emitting diodes demonstrated outstanding luminous characteristics, with a remarkable external quantum efficiency of 12.77% and a maximum luminance of 1449 cd m^–2 at 517 nm. These characteristics of the PNCs will have a wide variety of applications and will help enable development of highly efficient optoelectronic devices.

中文翻译：

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核壳结构中卤化物过量的钙钛矿纳米晶体的表面缺陷恢复


我们提出了一种通过使用过量的卤化物来恢复 CsPbBr₃/ZnS 核/壳纳米晶中的表面缺陷来合成稳定且均匀的高质量钙钛矿纳米晶 （PNC） 的方法。使用 N-溴琥珀酰亚胺作为卤化物供体恢复了 ZnS 壳生长过程中裸露的 CsPbBr₃ PNC 的表面卤化物空位，DFT 计算证实了这一点。这种方法实现了接近 1 的高光致发光量子产率，并显著提高了 PNC 在高湿度和高温等不利条件下的稳定性。CsPbBr₃/ZnS PNC 发光二极管表现出出色的发光特性，在 517 nm 处具有 12.77% 的显着外部量子效率和 1449 cd m^–2 的最大亮度。PNC 的这些特性将具有广泛的应用，并将有助于实现高效光电器件的开发。