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

摘要

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.