Electronic structures and optical properties of Hf-, Zr-and Nb-doped 2D (β-Ga2O3

The electronic structures and optical properties of 2D (1-Ga2O3 and Hf-, Zr-, Nb-doped 2D (1-Ga2O3 were systematically studied by GGA + U method based on density functional theory. Hf- and Zr-doped 2D (1-Ga2O3 tend to form under O-poor conditions while Nb-doped 2D (1-Ga2O3 tends to form under O-rich condition. Although Hf-, Zrand Nb-doped 2D (1-Ga2O3 can obtain high electron concentrations, Nb-doped 2D (1-Ga2O3 has deep donor levels and a large electron effective mass, which is not conducive to electron migration. In contrast, Hf- and Zrdoped 2D (1-Ga2O3 have good electrical conductivity and small work functions, which is easy to form ohmic contact with the metals. Besides, the optical absorption edges of Hf- and Zr-doped 2D (1-Ga2O3 are larger compared with 2D (1-Ga2O3 and Nb-doped 2D (1-Ga2O3, so Hf- and Zr-doped 2D (1-Ga2O3 are suitable as TCO materials for DUV optoelectronic devices. But Nb-doped 2D (1-Ga2O3 exhibits ferrimagnetic with a magnetic moment of 2 mu B and can be used as a spin material.