First-principle calculations of electronic structures and polar properties of (κ,ε)-Ga2O3

Physical properties of kappa- and epsilon-Ga2O3 are investigated using density functional theory. We utilized the supercell method considering the partial occupancies in epsilon-Ga2O3. The polarization values of these materials were analyzed to overcome the inconsistency between experimental and theoretical studies. The polarization values of kappa- and epsilon-Ga2O3 were similar to 26.39 and 24.44 mu C/cm(2), respectively. The bandgap values of 4.62 and 4.27 eV were estimated with the hybrid functional method, which suggested an underestimation of the PBEsol functional values of 2.32 and 2.06 eV for kappa- and epsilon-Ga2O3, respectively. (C) 2018 The Japan Society of Applied Physics