Electronic structures and optical properties of SnSe2(1−x)O2x alloys

Based on density functional theory, the electronic structures and optical properties of SnSe2(1−x)O2x alloys are investigated for the first time. Numerical results show that when oxygen concentration x increases ( x ⩽ 0.125 ), the band gap values of SnSe2(1−x)O2x alloys can be decreased from 1.03 to 0.77 eV, and the gap states are absent. The dielectric functions and optical absorptions are anisotropic in the SnSe2(1−x)O2x alloys. Moreover, the oxygen substitution of selenium affects obviously the optical properties along the x–y plane in the SnSe2(1−x)O2x alloys. These results are interesting and indicate that the SnSe2(1−x)O2x alloys with tunable band gap may serve as a promising candidate for near-infrared optical applications.