Chemically synthesized colloidal metal halide perovskite (MHP) nanocrystals (NCs) have high luminous efficiency, but they have long-chain organic ligands bound perpendicularly to the surface, which impede charge injection and transport, thereby causing charge accumulation and consequent degradation. This work presents an in situ crystallization strategy for polycrystalline MHP light emitters by altering the surface chemistry of MHPs, followed by lateral surface capping with a linear ionic homopolymer. This strategy directs in situ crystal growth termination to achieve nanocuboid grains that have well-terminated surfaces, resulting in enhanced photophysical properties and electrical homogeneity. Consequently, light-emitting diodes with the surface-tailored light emitters exhibit high luminance (>150 000 cd m^–2), high efficiency at elevated luminance (>102.1 cd A^–1 at 100 000 cd m^–2), low efficiency roll-off (0.58% reduction to emit 100 000 cd m^–2), and long-term stability (T₉₅ ≈ 243 h), simultaneously. This in situ crystallization combines the advantages of colloidal NCs and polycrystalline thin films while eliminating critical drawbacks of each approach.

中文翻译：

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化学设计的晶体生长终端，适用于高亮度和稳定的多晶钙钛矿 LED


化学合成的胶体金属卤化物钙钛矿 （MHP） 纳米晶体 （NC） 具有很高的发光效率，但它们具有垂直于表面的长链有机配体，这阻碍了电荷注入和传输，从而导致电荷积累和随之而来的降解。这项工作通过改变 MHP 的表面化学性质，然后用线性离子均聚物进行侧面封盖，提出了一种多晶 MHP 光发射器的原位结晶策略。该策略指导原位晶体生长终止，以实现具有良好终止表面的纳米长方体晶粒，从而增强光物理性能和电均匀性。因此，具有表面定制发光体的发光二极管表现出高亮度（>150 000 cd m^–2）、高亮度下的高效率（>102.1 cd A^–1 at 100 000 cd m^–2）、低效率滚降（发射 100 000 cd m^–2 时减少 0.58%）和长期稳定性 （T₉₅ ≈ 243 h）。这种原位结晶结合了胶体 NC 和多晶薄膜的优点，同时消除了每种方法的关键缺点。