CsPb2Br5 Single Crystals: Synthesis and Characterization

Abstract CsPb 2 Br 5 is a ternary halogen‐plumbate material with close characteristics to the well‐reported halide perovskites. Owing to its unconventional two‐dimensional structure, CsPb 2 Br 5 is being looked at broadly for potential applications in optoelectronics. CsPb 2 Br 5 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 CsPb 2 Br 5 bulk single crystals, which enabled us to finally clarify the material's optical features. Our CsPb 2 Br 5 crystal has a two‐dimensional structure with Pb 2 Br 5 − layers spaced by Cs + cations, and exhibits approximately 3.1 eV indirect band gap with no emission in the visible spectrum.