Quasi-two-dimensional Cs0.9Rb0.1PbBr2.1Cl0.9:PEABr sky-blue light-emitting diodes by potassium bromide doping engineering and interface modification in nickel oxide

The quasi-two-dimensional (QTD) Cs0.9Rb0.1PbBr2.1Cl0.9:PEABr perovskite sky-blue light-emitting diode (LED) was prepared through composition engineering, doping engineering and interface modification engineering by spin coating. The PEABr organic cations were introduced into three-dimensional (3D) perovskite through content proportional control. The solution of potassium bromide (KBr) was doped in the nickel oxide (NiOx) hole injection layer and the interface between the NiOx film and the perovskite film in the device structure. The optimized luminance and external quantum efficiency (EQE) of the sky-blue LED with Cs0.9Rb0.1PBBr2.1Cl0.9: 80 % PEABr were 989 cd/m2 and 0.68 %, respectively.