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.