Recently, substantial progress has been made in perovskite-based light-emitting devices (LEDs) with near-infrared, red, green, and blue emissions. However, short-wavelength perovskite LEDs targeted at violet emission remain a great challenge. Moreover, the majority of previously reported devices were focused on the conventional lead halide perovskites. In this study, for the first time, electrically driven violet emission (408 nm) from lead-free Cs₃Sb₂Br₉ quantum dots (QDs) was demonstrated at room temperature, the shortest wavelength for perovskite LEDs as far as we know, and an external quantum efficiency of ∼0.206% was achieved. The device demonstrated an excellent working stability. After a long-term running for 6 h, almost 90% of the initial electroluminescence performance was retained, and no current density rising occurred with the running time. The results obtained suggest that the lead-free Cs₃Sb₂Br₉ QDs are potentially attractive candidates for the preparation of environment-friendly and stable violet LEDs, making practical applications of them a real possibility.

中文翻译：

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基于高度稳定的无铅钙钛矿Cs ₃ Sb ₂ Br ₉量子点的电动紫罗兰色发光器件

近来，在具有近红外，红色，绿色和蓝色发射的基于钙钛矿的发光器件（LED）方面已经取得了实质性进展。但是，针对紫光发射的短波长钙钛矿LED仍然是一个巨大的挑战。此外，大多数先前报道的设备都集中在常规的卤化铅钙钛矿上。在这项研究中，无铅Cs ₃ Sb ₂ Br ₉首次电驱动紫光发射（408 nm）量子点（QDs）在室温下被证明，据我们所知，钙钛矿LED的最短波长，实现了约0.206％的外部量子效率。该设备表现出出色的工作稳定性。长期运行6小时后，几乎保持了90％的初始电致发光性能，并且随着运行时间的增加，电流密度没有发生上升。获得的结果表明，无铅Cs ₃ Sb ₂ Br ₉ QDs是制备环保，稳定的紫罗兰色LED的潜在诱人候选物，这使它们的实际应用成为现实。