Optical and electronic properties of defect chalcopyrite ZnGa₂S₄

Abstract

In this paper, we have performed a study on the optical properties of single crystals ZnGa2S4 by method of density functional theory (DFT) and ellipsometry measurements. The calculated results for the real [Formula: see text] and imaginary [Formula: see text] parts of the dielectric function are compared with the measured experimental spectroscopic ellipsometry (SE) spectra in the 0.7–6.5 eV spectral region. Absorption coefficient-photon energy dependency revealed the existence of direct bandgap transitions with energy 3.5 eV. This result is very close to bandgap obtained from our theoretical calculation.