First principle calculation of structural, electronic and optical properties of CdS and doped Cdx-1AxS (A=Co, Fe, Ni) compounds

Abstract

The structural, electronic and optical properties of pure Cadmium sulfide (CdS) and its alloy Cdx-1AxS(A = Co, Fe and Ni) compounds were investigated using first principle based on density functional theory. Electronic band structure and optical parameters calculations were performed using two different methods; generalized gradient approximation in Perdew-Burke-Ernzerhof (PBE) as well as modified Becke-Johnson (mBJ) for the exchange-correlation potential. Lattice constant, volume and bulk modulus were evaluated for structural properties. The results of band structure, effective mass, density of states and magnetic moment were determined for electronic properties. Optical parameters including absorption coefficient, refractive index, optical conductivity and optical reflectivity have been computed from the dielectric function at energy range of 0 to 15 eV using the Kramers-Kronig transformations. Our results reveal that the present of dopant in pure CdS enhanced the absorption capacity at low energy regions with the absorption coefficient of Cd0.75Fe0.25 > Cd0.75Co0.25S > Cd0.75Ni0.25S > Pure CdS for the GGA-PBE method and Cd0.75Fe0.25 > Cd0.75Ni0.25S > Cd0.75Co0.25S > Pure CdS for the mBJ method. The ability of Cd0.75Fe0.25 and Cd0.75Ni0.25S to absorb at extensive range of electromagnetic radiation makes them potential materials for application in nano-optoelectronic industry. All the results were compared with available theoretical calculations and the experimental data.