Spectroscopic ellipsometry investigation of optical properties of β-Ga2S3 single crystals

Abstract

Ga2S3 single crystals were studied by x-ray diffraction (XRD), energy dispersive spectroscopy and spectroscopic ellipsometry measurements. XRD pattern of the sample is well-matched with reported hexagonal structure of β-Ga2S3. The spectra of real and imaginary parts of complex dielectric function (ɛ = ɛ1 + iɛ2) and refractive index (N = n + ik) were plotted in the 1.2–6.2 eV range according to results of ellipsometric data. The ɛ2-spectrum and analyses of absorption coefficient pointed out that studied sample has band gap energy of 2.48 eV which is consistent with that of β-Ga2S3. Critical point energies of β-Ga2S3 were also reported in the present study.