Ultra-bright pure green perovskite light-emitting diodes

Inorganic perovskites, such as CsPbX3 (X = Cl, Br, I), have attracted attention due to their excellent thermal stabilities and high photoluminescence quantum efficiencies. Here, we report on all-inorganic light-emitting diodes (LEDs), including inorganic perovskite emitters (CsPbBr3) based on the heterostructure of n-ZnO/Al2O3/CsPbBr3/p-GaN. The effects of the CsPbBr3 and Al2O3 interlayers on the electroluminescence performance have been systematically investigated. It is observed that the Al2O3 interlayer plays an important role in determining the emission performance. By introducing the Al2O3 layers, the electron–hole recombination can almost be limited within the perovskite. The emission peaks of the heterojunction LEDs change from blue-green to pure green with the increased luminous intensities and decreased leakage currents. It provides an idea for the preparation of all-inorganic perovskite LEDs.