Mechanosynthesis strategy towards a high-efficiency CsPbBr3/Cs4PbBr6 perovskite phosphor

All-inorganic perovskites are promising alternatives to organic-inorganic hybrid halide perovskites in the field of optoelectronic materials. Optimizing the luminescent property of CsPbBr3 is very important to promote its application in optoelectronic devices, and thus a facilitative method to prepare a large number of efficient luminous samples is desirable. In this study, we effectively improve the luminous performance of CsPbBr3 powder by a simple mechanosynthesis strategy. The emission intensity of CsPbBr3 powder is improved by ca. 40 times and the PLQY of the powder sample exceeds 40%. It is disclosed that the defects of CsPbBr3 are passivated and the ratio of the non-radiation recombination is reduced. The formed Cs4PbBr6 during grinding has a zero-dimensional perovskite structure that can limit the migration of the carriers between the [PbBr6] octahedrons. Now CsPbBr3 can be used in powder form other than film or quantum dots. A UV-chip LED is fabricated by using the prepared phosphor, and the narrow-band emission property (FWHM is 22 nm) makes it more suitable for application in back-lighting systems.