The white emissions based on lead‐free perovskites with broadband emission due to self‐trapped excitons (STEs) are considered as an ideal candidate for next‐generation white light‐emitting diodes (WLEDs). Recently, copper‐based halide perovskites Cs3Cu2I5@CsCu2I3 composites films with a high color‐rendering index (CRI) have been developed for WLEDs. However, the Cs3Cu2I5@CsCu2I3 composites generally exhibit a relatively low photoluminescence quantum yield (PLQY). Herein, a high PLQY up to 86.75% copper‐based perovskite Gua3Cu2I5 (Gua = guanidine) films with a broadband strong yellow STEs emission centered at 544 nm is synthesized. By combining with efficient blue STEs emission Cs3Cu2I5 component via composition engineering of Cs3Cu2I5@Gua3Cu2I5, a high PLQY of up to 96.1% is achieved on the white emission composites films. Moreover, a high CRI of 93 WLEDs is achieved by integrating Cs3Cu2I5@Gua3Cu2I5 composites film onto a UV LED chip. These findings provide a simple and effective strategy for designing highly efficient white light‐emitting diodes.

中文翻译：

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铜基钙钛矿化合物的高性能白光发射

基于无铅钙钛矿的白光发射，由于自陷激子（STE）而具有宽带发射，被认为是下一代白光发光二极管（WLED）的理想候选者。近年来，铜基卤化物钙钛矿Cs3铜2我5@CsCu2我3具有高显色指数 (CRI) 的复合薄膜已被开发用于 WLED。然而，铯3铜2我5@CsCu2我3复合材料通常表现出相对较低的光致发光量子产率（PLQY）。其中，铜基钙钛矿的 PLQY 高达 86.75%3铜2我5合成了具有以 544 nm 为中心的宽带强黄色 STE 发射的 (Gua = 胍) 薄膜。通过与高效的蓝色 STE 发射 Cs 相结合3铜2我5通过 Cs 的成分工程组成3铜2我5@瓜3铜2我5，白光发射复合薄膜的 PLQY 高达 96.1%。此外，通过集成 Cs 实现了 93 WLED 的高 CRI3铜2我5@瓜3铜2我5复合薄膜到 UV LED 芯片上。这些发现为设计高效白光发光二极管提供了一种简单而有效的策略。