The electronic structure, optical property and n-type conductivity for W-doped <i>α</i>-Ga<sub>2</sub>O<sub>3</sub>: hybrid functional study
Jinyan Chang, Sixin Kang, Yu Chen, Shuaiwei Fan
Abstract
Abstract Based on the hybrid functional method, the electronic structure, optical property and electron effective mass of α -Ga 2 O 3 , together with the properties for intrinsic and extrinsic defects incorporated into α -Ga 2 O 3 are studied. Obtained results indicate the α -Ga 2 O 3 possesses a wide band gap (5.31 eV), small electron effective mass (0.22 m 0 ) and a high visible light transmittance. The nonstoichiometric α -Ga 2 O 3 is not an excellent n-type semiconductor. To improve the n-type conductivity, the W-doped α -Ga 2 O 3 is studied. We find that W Ga is a promising n-type defect due to its relatively small ionization energy ϵ (0/+) (0.30 eV). When the equilibrium fabrication method is selected, the WO 2 is a promising dopant source. Using the equilibrium fabrication method, the defect complex ( V O + W Ga ) would be formed, and the ionization energy ϵ (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 α -Ga 2 O 3 and provide significant insights for the development of a transparent n-type semiconductor.