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

Based on the hybrid functional method, the electronic structure, optical property and electron effective mass of alpha-Ga2O3, together with the properties for intrinsic and extrinsic defects incorporated into alpha-Ga2O3 are studied. Obtained results indicate the alpha-Ga2O3 possesses a wide band gap (5.31 eV), small electron effective mass (0.22 m0) and a high visible light transmittance. The nonstoichiometric alpha-Ga2O3 is not an excellent n-type semiconductor. To improve the n-type conductivity, the W-doped alpha-Ga2O3 is studied. We find that W Ga is a promising n-type defect due to its relatively small ionization energy & varepsilon;(0/+) (0.30 eV). When the equilibrium fabrication method is selected, the WO2 is a promising dopant source. Using the equilibrium fabrication method, the defect complex (V O+ W (Ga)) would be formed, and the ionization energy & varepsilon;(0/+) for defect complex (V O + W- Ga) would decrease to 0.08 eV, which implies that a great number of free electrons could be induced in the samples. We expect that this work can promote the understanding of the n-type conductivity for alpha-Ga(2)O(3 )and provide significant insights for the development of a transparent n-type semiconductor.