DFT study of optoelectronic spectra of barium cadmium chalcogenides (Ba₂CdX₃, X = S, Se and Te)

DFT analyses of electronic and optical spectra of barium cadmium chalcogenides (Ba₂CdX₃, X = S, Se, Te) have been carried out. The study of electronic spectra has been made in terms of band structure and density of states using full potential linear augmented plane wave plus local orbital method. Band structure calculations have been carried out under the approximations PBE-GGA, PBE-Sol, LDA and TB-mBJ. Band structures of these materials show that Ba₂CdS₃, Ba₂CdSe₃ and Ba₂CdTe₃ crystals possess a band gap less than 1 eV, underestimated relative to the experimental/theoretical literature values. Optical spectra of these chalcogenides have been analyzed in terms of real and imaginary parts of dielectric function, reflectivity, refractive index, extinction coefficient, absorption coefficient, optical conductivity and electron energy loss. Optical results show large anisotropy along different directions. These results provide a physical basis of barium cadmium chalcogenides for potential application in optoelectronic devices.