CsPbBr₃ perovskite nanoplatelets capped with inorganic ligands for stable deep blue emission

All-inorganic halide perovskite materials have attracted significant interest for display applications because of their narrow bandwidths and high photoluminescence quantum yields. However, the development of blue-light-emitting perovskite materials has been slower than that of green- and red-light-emitting perovskites. In this study, we successfully produced single-halide CsPbBr₃ nanoplatelets with a quantum confinement effect using ligand-assisted reprecipitation techniques. NaBr, an inorganic ligand with strong binding affinity (adsorption energy, -2.13 eV) and low steric hindrance, was used to prevent the continued growth of nanoplatelets. A series of experimental results demonstrate that CsPbBr₃ nanoplatelets with a dense Na⁺ shell on the surface exhibit stable deep blue emission. UV chip-based light-emitting devices activated by these nanoplatelets demonstrated remarkable spectral stability as the current injection increased. Moreover, the synthesis process is conducted under simple conditions at room temperature, demonstrating potential for batch production.