Syntheses, crystal structure, and photoelectric properties of two selenoantimonates A–Zn–Sb–Se (A = Rb and Cs)

Metal chalcogenides, as a new class of semiconductor materials, have a broad range of applications in synthetic chemistry due to their rich structures and excellent properties. We have synthesized two selenoantimonates A₄Zn₂Sb₂Se₇ [A = Rb(1), Cs(2)] under solvothermal conditions in the visible region using a band gap optimization strategy with alkali metals as structure-directing agents. Compounds 1 and 2 have a two-dimensional layered structure consisting of charge-balanced Rb⁺(1) or Cs⁺(2) cations and [Zn₂Sb₂Se₇]^4- anions with novel 20-membered rings (20-MR) [Zn₆Sb₄Se₁₀] with an aperture of 5.6949 × 13.7741 Ų formed in the middle. Furthermore, we have investigated the crystal structure, band gap, photoelectronic properties, and energy band structure.