Cesium lead halide perovskites (CsPbX₃) have become superior candidates for perspective optoelectronic applications. However, room temperature synthesized CsPbX₃ nanocrystals (NCs) suffer from serious lattice surface traps, mostly induced by nonequilibrium reactions and polar solvent systems. Thus, direct assembly of such poor crystals cannot be available toward high efficiency light emitting diodes (LEDs). To address this issue, differing from the general post-treatment works, here we propose a double-terminal diamine bromide salts to in situ passivate the surface traps of room temperature synthesized CsPbBr₃ NCs. High-quality NC solutions with photoluminescence quantum yield (PLQY) beyond 90% are obtained owing to the renovated surface bromide vacancies. Meanwhile, instead of longer oleylamine (OLA) ligand, the abridged diamine bromine ligand could significantly enhance charge transport throughout the NC film. In addition, the NC based LED performance is found related to chain length of the ligand, where the optimal luminance of 14021 Cd m⁻² and current efficiency of 25.5 Cd A⁻¹ are achieved by 1, 4-butanediamine bromide passivated NC devices. This work provides a direct efficient approach to meet the device application of room temperature synthesized perovskite NCs, underlines the significance of selective ligands to address the challenges of NC emitters in future displays and solid-state lighting.

铯卤化钙铅钙钛矿（CsPbX ₃）已成为透视光电应用的最佳候选者。但是，室温合成的CsPbX ₃纳米晶体（NCs）遭受严重的晶格表面陷阱，主要是由非平衡反应和极性溶剂系统引起的。因此，不能将这种不良晶体的直接组装用于高效发光二极管（LED）。为了解决此问题，与一般的后处理工作不同，我们在此提出了一种双末端二胺溴化物盐，以原位钝化室温下合成的CsPbBr ₃的表面阱NCs。由于翻新的表面溴化物空位，获得了具有90％以上的光致发光量子产率（PLQY）的高质量NC解决方案。同时，取代了更长的油胺（OLA）配体，节制的二胺溴配体可以显着增强整个NC膜中的电荷传输。另外，发现基于NC的LED性能与配体的链长有关，其中最佳亮度14021 Cd m ^-2和电流效率25.5 Cd A ^-1通过1，4-丁二胺溴化物钝化NC设备可实现。这项工作为满足室温合成钙钛矿型NC的设备应用提供了一种直接有效的方法，强调了选择性配体的重要性，以应对未来显示器和固态照明中NC发射器的挑战。