Density functional theory: The structural, electronic, optical, mechanical, and vibrational properties of bulk and Te-doped SnSe2

Abstract

This work performs a computational prediction on SnSe2 and Te-doped bilayer material. Doping the Te element onto SnSe2 can lead to a decrease in bandgap [Formula: see text] energy (from 1.95 eV to 0.94 eV) and cause a drop in both conduction band (CB) and valence band (VB), apart from the valence band maximum (VBM). This may lead to an increase in electrical conductivity. The decrease in [Formula: see text] parameter may result in an impact on electronic effective mass and transport properties when the SnSe2 bilayer is doped with Te. A redshift observed on both the optical absorption and the dielectric constant plots may suggest that a tensile force could be possibly induced when we dope the SnSe2 compound. The identical elastic constants of C[Formula: see text] and C[Formula: see text] evaluated could describe the nature of the close-packed hexagonal bilayer. Finally, the ductility slightly increases when we mix the Te element onto the SnSe2 alloy. It is also worth noting that both SnSe2 and Te-doped are dynamically stable, according to the phonon dispersion.