Absorption edge characteristics of β-Ga2O3 single crystal

The intrinsic absorption edge of a [Formula: see text] single crystal is examined by spectroscopic ellipsometry. An absorption model consisting of five parameters including absorption amplitude, bandgap energy, Urbach energy and two power exponents is developed to describe the absorption characteristics of the [Formula: see text] single crystal. The anisotropic bandgap energies obtained from the model are 4.938, 5.030 and 5.100 eV, respectively. These values obtained from the model agree well with values derived from the first derivative maximum of k and maximum of n method.