Lead halide perovskites have drawn extensive attention over recent decades owing to their outstanding photoelectric performances. However, their toxicity and instability are big issues that need to be solved for further commercialization. Herein, we adopt a facile dry ball milling method to synthesize lead-free Cs3Cu2X5 (X=I, Cl) perovskites with photoluminescence (PL) quantum yield up to 60%. The optical features including broad emission spectrum, large Stokes shift, and long PL lifetime can be attributed to self-trapped exciton recombination. The as-synthesized blue emissive Cs3Cu2I5 and green emissive Cs3Cu2Cl5 lead-free perovskite powders have good thermal stability and photostability. Furthermore, UV-pumped phosphor-converted light-emitting diodes were obtained by using Cs3Cu2I5 and Cs3Cu2Cl5 as phosphors.

中文翻译：

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用于紫外泵浦荧光粉转换发光二极管的高发光稳定无铅卤化铯铜钙钛矿粉末

近几十年来，卤化铅钙钛矿因其出色的光电性能而受到广泛关注。然而，它们的毒性和不稳定性是进一步商业化需要解决的大问题。在此，我们采用简便的干球磨法合成了光致发光 (PL) 量子产率高达 60% 的无铅 Cs3Cu2X5 (X=I, Cl) 钙钛矿。包括宽发射光谱、大斯托克斯位移和长 PL 寿命在内的光学特征可归因于自陷激子复合。合成的蓝色发光 Cs3Cu2I5 和绿色发光 Cs3Cu2Cl5 无铅钙钛矿粉末具有良好的热稳定性和光稳定性。此外，通过使用 Cs3Cu2I5 和 Cs3Cu2Cl5 作为荧光粉，获得了紫外泵浦荧光粉转换发光二极管。