CsPb2Br5 Single Crystals: Synthesis and Characterization.

CsPb₂Br₅ is a ternary halogen-plumbate material with close characteristics to the well-reported halide perovskites. Owing to its unconventional two-dimensional structure, CsPb₂Br₅ is being looked at broadly for potential applications in optoelectronics. CsPb₂Br₅ investigations are currently limited to nanostructures and powder forms of the material, which present unclear and conflicting optical properties. In this study, we present the synthesis and characterization of CsPb₂Br₅ bulk single crystals, which enabled us to finally clarify the material's optical features. Our CsPb₂Br₅ crystal has a two-dimensional structure with Pb₂Br₅⁻ layers spaced by Cs⁺ cations, and exhibits approximately 3.1 eV indirect band gap with no emission in the visible spectrum. [ABSTRACT FROM AUTHOR]