Perovskite nanocrystals (PNCs) have recently become promising optoelectronic materials due to their excellent photophysical properties. However, the highly dynamic binding state between ligands and the surface of PNCs has severely restricted their luminescent properties and stabilities. In this work, 1,3-bisbenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid (cycle acid, CA) is introduced as both an etchant and a ligand upon post-synthetic surface treatment of PNCs. By removing the imperfect octahedrons [PbX₆]⁴⁻ and passivating the surface defects synergistically, this treatment improves photoluminescence quantum yields from 76% to 95% and enhances the stability of PNCs against polar solvent, moisture, heat, and illumination. Meanwhile, CA can effectively and instantly recover the luminescence emission for aged PNCs. As a result, the CA-CsPbBr₃ PNCs and CA-CsPbI_xBr_3−x PNCs are applied as color-converting layers on a blue LED chip for warm white light-emitting diodes (WLEDs) with a color coordinate of (0.41, 0.40). Importantly, the CA-based WLED device exhibits superior stability in operational conditions.

钙钛矿纳米晶体（PNCs）由于其优异的光物理性质，最近成为有前途的光电材料。然而，配体与 PNC 表面之间的高度动态结合状态严重限制了它们的发光特性和稳定性。在这项工作中，1,3-bisbenzyl-2-oxoimidazolidine-4,5-dicarboxy 酸（循环酸，CA）在 PNC 的合成后表面处理中作为蚀刻剂和配体被引入。通过去除不完美的八面体 [PbX ₆ ] ⁴⁻并协同钝化表面缺陷，这种处理将光致发光量子产率从 76% 提高到 95%，并增强了 PNC 对极性溶剂、水分、热和光照的稳定性。同时，CA 可以有效且即时地恢复老化 PNCs 的发光发射。因此，CA-CsPbBr ₃ PNCs 和 CA-CsPbI _x Br _{3− x} PNCs 被用作蓝色 LED 芯片上的颜色转换层，用于色坐标为 (0.41, 0.40）。重要的是，基于 CA 的 WLED 器件在操作条件下表现出卓越的稳定性。