Optimizing Broadband Emission in 2D Halide Perovskites

Broadband and white-light emitting materials are sought after for applications such as phosphors and LEDs. Some two-dimensional (2D) halide perovskites are promising candidates in this realm. Nevertheless, optimizing their photoluminescence quantum efficiency (PLQY) is highly challenging. Herein, we show a new strategy for optimizing the efficiency of the broadband emission of 2D halide perovskites. Specifically, we show that by a combination of halide bonds and halide mixing, the PLQYs of a novel family of materials with the formula (Br-PEA)2PbBrxCl4–x (Br-PEA = 4-bromo phenethylammonium) can be improved by one order of magnitude, from 3 to 25%; this approach could be useful to many other 2D perovskites.

宽带发射与白光发射材料在荧光粉、发光二极管等应用中广受青睐。部分二维卤化物钙钛矿（two-dimensional halide perovskites）是该领域极具潜力的候选材料。然而，优化其光致发光量子效率（photoluminescence quantum efficiency，PLQY）仍极具挑战。本文提出了一种优化二维卤化物钙钛矿宽带发射效率的全新策略。具体而言，通过结合卤键与卤化物混合策略，一类通式为(Br-PEA)₂PbBrₓCl₄₋ₓ（其中Br-PEA为4-溴苯乙胺）的新型材料的光致发光量子效率可提升一个数量级，从3%提升至25%；该方法对诸多其他二维钙钛矿同样具有应用价值。