We demonstrate a simple method to synthesis thermally stable and green luminescent ligand-free Cs 4 PbBr 6 nanospheres (NS) with a polar solvent. In this approach, a single polar solvent, N,N-dimethylformamide (DMF) is sufficient enough to convert precursors into cubic shaped ligand-free Cs 4 PbBr 6 crystals. Further, the morphology of cubic shaped Cs 4 PbBr 6 crystals is reformed into spherical shaped Cs 4 PbBr 6 NS by prolonged DMF washing (overnight stirring, 15 h). Besides, the reduction in average particle size of spherical shaped Cs 4 PbBr 6 NS (~70 nm) to one-fourth to the original size of cubic Cs 4 PbBr 6 crystals (~310 nm). The ligand-free spherical shaped Cs 4 PbBr 6 NS showed a high photoluminescence quantum yield of 42.5%, which could compete the conventional ligand mediated Cs 4 PbBr 6 crystals. Moreover, spherical shaped Cs 4 PbBr 6 NS exhibited a high thermal stability even at 200 °C without sacrificing luminescence intensity. Hence, it is foreseen that this approach brings a new strategy to prepare ligand-free Cs 4 PbBr 6 NS as a promising material in optoelectronic devices.
- Cs PbBr
- Single solvent
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics