High-quality CsPbBr3 perovskite nanocrystals for quantum dot light-emitting diodes

Abstract

Metal halide perovskites, such as CsPbX3 (X = Cl, Br, and I), have gained extensive attention due to their increasing demand in optoelectronic applications such as solar cells and lighting-emitting devices. Herein, we report a versatile approach to synthesize high-quality CsPbBr3 perovskite nanocrystals (sized 5-15 nm) by ligand-assisted reprecipitation at room temperature. The monodispersed CsPbBr3 nanocube perovskites displayed relatively high photoluminescence quantum yields of 50-80%. By virtue of the quantum size effects, the bandgap energies were manipulated from blue to green spectral regions (410-530 nm). In addition, through compositional modulations of the anion exchange technique, the bright photoluminescence could be almost tuned over the entire visible spectral region (450-650 nm). Furthermore, the photoluminescence of the CsPbBr3 nanocrystals was characterized by narrow emission line widths of 15-50 nm and radiative lifetimes of 5-15 ns. Finally, by taking advantage of these outstanding merits, the CsPbBr3 perovskites were successfully utilized in the application of highly fluorescent patterning and color-purity light-emitting diodes.