CsPbBr3 and Cs4PbBr6 perovskite light-emitting diodes using a thermally evaporated host–dopant system

This article shows the results of fabricating a device through vacuum deposition by synthesizing a perovskite thin film in the powder form. Light emitting diodes (LEDs) were fabricated using a single-source and host-dopant system of the perovskite produced in the powder form. Both CsPbBr₃ and Cs₄PbBr₆ used in the host-dopant system were green, and the host was tris(8-quinolinolato) aluminum(III). It is confirmed that the display efficiency and optical characteristics are significantly improved by the dopant ratio. The 3%-doped CsPbBr₃ based LED shows a luminance of 9083 cd m^-2, 3.36% external quantum efficiency (EQE), and 96% photoluminescence quantum yield (PLQY) efficiency (for the undoped CsPbBr₃ LED, luminance: 844 cd m^-2/EQE: 1.93%/PLQY: 85%). The LED based on 5%-doped Cs₄PbBr₆ shows a luminance of 11 440 cd m^-2, an EQE of 6.27%, and 99% PLQY efficiency (for the undoped Cs₄PbBr₆ LED, luminance:1113 cd m^-2/EQE: 1.64%/PLQY: 93%). It is expected that the results of this research will contribute to the perovskite LED research performed by thermal evaporation in the future.