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. The antisolvent paradox: Ternary halogen‐plumbate compounds like CsPb2Br5 are capturing the attention of the optoelectronic community. However, fundamental knowledge of their intrinsic properties is still missing. Here, we present the synthesis of CsPb2Br5 single crystals by an antisolvent‐vapor crystallization method and their characterization.