Light-emitting diodes (LEDs) employing all-inorganic CsPbX₃ (X = Cl, Br, I) perovskite quantum dots offer a huge potential in terms of high electroluminescence efficiency, color purity, and wide color gamut. However, the unbalanced charge injection and low ion-migration activation energy in perovskite active layers may cause device efficiency to decline with the increase of brightness and current density, which is a so-called efficiency roll-off effect. In this Perspective, we offer design principles toward construction of ionic crystal {perovskite}/atomic crystal {semiconductor alloy materials} core/shell quantum dots, which can serve as emitters for perovskite-based LEDs with a low efficiency roll-off. Considering the lattice constant matching and the proper energy level arrangement for the core and shell, we suggest that the CsPbI₃/Mg_xZn_1–xTe core/thick shell quantum dots may simultaneously offer enhanced emission, balanced charge injection, and suppressed ion migration and thus be a suitable emitter for LEDs with simultaneous high brightness and efficiency.

中文翻译：

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带有原子晶体壳的钙钛矿量子点，用于低效率滚降的发光二极管

采用全无机CsPbX ₃的发光二极管（LED）（X = Cl，Br，I）钙钛矿量子点在高电致发光效率，色纯度和宽色域方面具有巨大潜力。然而，钙钛矿活性层中的不平衡电荷注入和低离子迁移活化能会导致器件效率随着亮度和电流密度的增加而下降，这就是所谓的效率衰减效应。在此《观点》中，我们提供了离子晶体{钙钛矿} /原子晶体{半导体合金材料}核/壳量子点构造的设计原理，这些核可以用作低效滚降的基于钙钛矿的LED的发射器。考虑到晶格常数匹配和核和壳的适当能级布置，我们建议CsPbI ₃ / Mg _x Zn_{1– x} Te核/厚壳量子点可以同时提供增强的发射，平衡的电荷注入和抑制的离子迁移，因此是同时具有高亮度和高效率的LED的合适发射器。