Ca2SnS4: Crystal structure, optical property, and electronic structure

• Ca2SnS4 crystals have been synthesized and characterized for the first time.
• The structure contains bi-layers with isolated polyhedra residing in the cavities.
• Ca2SnS4 has a band gap of 2.32(3) eV, comparable to the calculated value 2.72 eV.

single crystals of Ca2SnS4were obtained by traditional high temperature solid-state reaction. The compound crystallizes in space group Pnma of the orthorhombic system. Its structure contains bi-layers built from corner-sharing Ca1S6 octahedra and Ca2S6 octahedra with isolated SnS4 tetrahedra residing in the cavities along the b axis. UV–vis-NIR spectroscopy measurement indicates that Ca2SnS4 has a band gap of 2.32(3) eV, comparable to the calculated value 2.72 eV.