Effect of cation vacancy on lattice and luminescence properties in CsPbBr3 quantum dots

All-inorganic perovskite quantum dots have been widely used in solar cells, LED, laser and scintillator in recent years. However, the essence of ion migration in perovskite lattice can cause the ion vacancies exist, which can directly affect the luminescence process. Herein, we focus on the effect of monovalent cation vacancies on the CsPbBr 3 lattice, and realize the adjusting lattice structure of the CsPbBr 3 QDs to change the luminescence lifetime by controlling the formation of monovalent cation vacancies. The results show that the existence of monovalent cation vacancies can be controlled by controlling dosages of Cs  +  precursor and can make the CsPbBr 3 lattice produce local lattice micro distortion and reduce luminescence lifetime, which is beneficial to realize the rapid and efficient X-ray imaging of scintillating crystals. Experimental result is also verified by density functional theory (DFT).