Syntheses, crystal structure, and electronic properties of the five ABaMQ4 compounds RbBaPS4, CsBaPS4, CsBaVS4, RbBaVSe4, and CsBaVSe4

• Five new ABaMQ4 compounds were synthesized by solid-state chemistry at 1123 K.
• RbBaPS4, CsBaPS4, CsBaVS4, RbBaVSe4, and CsBaVSe4 have the TlEuPS4 structure type.
• The compounds are semiconductors with calculated band gaps ranging from 1.6 to 3.4 eV.

Five new compounds belonging to the ABaMQ4 family were synthesized by solid-state chemistry at 1123 K. The compounds RbBaPS4, CsBaPS4, CsBaVS4, RbBaVSe4, and CsBaVSe4 are isostructural and have the TlEuPS4 structure type. They crystallize in space group D162h – Pnma of the orthorhombic system. Their structure consists isolated MQ4 tetrahedra separated by A and Ba atoms to form a salt-like structure. Density Functional Theory (DFT) calculations of the electronic structures with the use of the HSE functional suggest that the compounds are semiconductors with calculated band gaps of 3.3 eV (RbBaPS4), 3.4 eV (CsBaPS4), 2.3 eV (CsBaVS4), and 1.6 eV (RbBaVSe4).

General view of the ABaMQ4 structure down the a axis.Figure optionsDownload as PowerPoint slide