Light-emitting diodes (LEDs) based on metal halide perovskite quantum dots (QDs) have achieved impressive external quantum efficiencies; however, the lack of surface protection of QDs, combined with efficiency droop, decreases device operating lifetime at brightnesses of interest. The epitaxial incorporation of QDs within a semiconducting shell provides surface passivation and exciton confinement. Achieving this goal in the case of perovskite QDs remains an unsolved challenge in view of the materials’ chemical instability. Here, we report perovskite QDs that remain stable in a thin layer of precursor solution of perovskite, and we use strained QDs as nucleation centers to drive the homogeneous crystallization of a perovskite matrix. Type-I band alignment ensures that the QDs are charge acceptors and radiative emitters. The new materials show suppressed Auger bi-excition recombination and bright luminescence at high excitation (600 W cm^–2), whereas control materials exhibit severe bleaching. Primary red LEDs based on the new materials show an external quantum efficiency of 18%, and these retain high performance to brightnesses exceeding 4700 cd m^–2. The new materials enable LEDs having an operating half-life of 2400 h at an initial luminance of 100 cd m^–2, representing a 100-fold enhancement relative to the best primary red perovskite LEDs.

中文翻译：

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基于钙钛矿矩阵中钙钛矿量子点的明亮而稳定的发光二极管

基于金属卤化物钙钛矿量子点 (QD) 的发光二极管 (LED) 已经实现了令人印象深刻的外部量子效率；然而，QD 缺乏表面保护，加上效率下降，会降低器件在感兴趣的亮度下的工作寿命。量子点在半导体壳内的外延结合提供了表面钝化和激子限制。鉴于材料的化学不稳定性，在钙钛矿 QD 的情况下实现这一目标仍然是一个未解决的挑战。在这里，我们报告了钙钛矿量子点在钙钛矿的前体溶液薄层中保持稳定，并且我们使用应变量子点作为成核中心来驱动钙钛矿基质的均匀结晶。I 型带对齐确保 QD 是电荷受体和辐射发射器。^–2 )，而对照材料表现出严重的漂白。基于新材料的初级红色 LED 显示出 18% 的外部量子效率，并且在超过 4700 cd m ^{–2 的}亮度下仍保持高性能。新材料使 LED 在 100 cd m ^–2的初始亮度下具有 2400 小时的工作半衰期，相对于最好的初级红色钙钛矿 LED 增强了 100 倍。