Efficient light-emitting devices based on mixed-cation lead halide perovskites

In this work, we report the morphology, crystal structure, photo-physics, and electroluminescence characteristics of perovskite materials containing a mixture of methylammonium (MA) and ethylammonium (EA) cations with the form MA(x)EA((1-x))PbBr(3). Hybridization of MA and EA cations simultaneously increases the photoluminescence quantum yield and thermal-, environmental-, and photo-stability of perovskite materials as the result of crystal structure modification, defect passivation, and morphology improvement. The addition of a large-group ammonium bromide further reduces defect density and raises the maximum external quantum efficiency of related light-emitting devices to 14.5%. These findings enrich the library of A-site cations for efficient perovskite light-emitting devices and may pave the way toward the realization of high performance multication perovskites-based light-emitting devices.