Pb3SBrI3: the first Pb-based chalcohalide with multiple halogens features a unique two-dimensional structure composed of diverse Pb-centered polyhedra

Abstract

Chalcohalides are attractive multifunctional candidates for new material due to their diverse crystal structures and the characteristics that come from the fusing of chalcogenides and halides. Here, we successfully synthesized a new Pb-based chalcohalide with multiple-halogens, namely, Pb₃SBrI₃, via a hydrothermal reaction using an organic chemical as the source of the sulfur. The Pb₃SBrI₃ exhibits unique neutral [Pb₃SBrI₃]_∞ layers composed of rich Pb-centered units including PbS₃ trigonal pyramids, PbSI₄ square pyramids, and PbBr₂I₄ octahedra that are piled along the a-axis. Notably, the Pb₃SBrI₃ is the first Pb-based chalcohalide featuring such a 2D structure. In this work, we examined in detail its synthesis, crystal structure, optical properties and theoretical calculation results.