Abstract
A computational study based on the density functional theory calculations is carried out for the band structure and optical spectra of bulk, tri-layer, bi-layer and monolayer CdS system in the hexagonal-wurtzite structure. The aim of this contribution is to see how the electronic and optical properties of CdS change when moving from the bulk form to the monolayer one through tri-layer and bi-layer Cds systems. Our results show that the monolayer form still has a direct ( CYRILLIC CAPITAL LETTER GHE- CYRILLIC CAPITAL LETTER GHE) band gap, but with an increased magnitude with respect to that of bulk CdS. The optical properties of the tri-layer, bi-layer and monolayer form are found to be different from those of the bulk form. An anisotropic character has been shown by the optical spectra for light polarized parallel and perpendicular to the x axis of the crystal. Our findings indicate that novel electronic and optical properties may be obtained when passing from bulk to tri-layer, bi-layer and monolayer CdS system.