Ab initio calculations and experimental study of the electronicproperties of CdGa-=SUB=-2-=/SUB=-S-=SUB=-4-=/SUB=- single crystals by spectralellipsometry

The electronic properties of CdGa2S4 single crystals have beenstudied experimentally using spectral ellipsometry and theoretically from first principles using density functional theory (DFT). Using ellipsometric studies in the energy range of 0.7-6.5 eV, theimaginary and real parts of the dielectric function along and perpendicularto the optical axis, the dispersion of the refractive, extinction, andabsorption coefficients are determined. The width of the direct band gap isestimated. The band structure, the origin of the energy states, the opticalfunctions, and the partial densities of states (PDOS) projected onto theatoms are determined by ab initio calculations. The theoretically calculated results are compared with the experimentaldata of the present work obtained by the method of spectral ellipsometry andwith the experimental results available in the literature. Keywords: spectral ellipsometry, ellipsometric angles, dielectricfunction, refractive index, extinction coefficient, Brillouin zone, bandstructure.\