The electronic structure, optical property and n-type conductivity for W-doped α-Ga2O3: hybrid functional study

Abstract Based on the hybrid functional method, the electronic structure, optical property and electron effective mass of α-Ga2O3, together with the properties for intrinsic and extrinsic defects incorporated into α-Ga2O3 are studied. Obtained results indicate the α-Ga2O3 possess wide band gap (5.3 eV), small electron effective mass (0.22 m0) and high visible light transmittance. The nonstoichiometric α-Ga2O3 is not an excellent n-type semiconductor. To improve the n-type conductivity, the W-doped α-Ga2O3 is studied. We find WGa is promising n-type defect for its relative small ionization energy ε(0/+) (0.30 eV). When the equilibrium fabrication method is selected, the WO2 is promising dopant source. Using the equilibrium fabrication method, the defect complex (VO+WGa) would be formed, and the ionization energy ε(0/+) for defect complex (VO+WGa) would decrease to 0.08 eV, which implies a great number of free electrons could be induced in the samples. We expect this work can promote the understanding of the n-type conductivity for α-Ga2O3 and provide significant insights for the development of a transparent n-type semiconductor.