Invesigation of the electronic structure and Optoelectronic properties of Si-doped β-Ga2O3 using GGA+U method based on first-principle

In this work, the formation energy, band structure, state density, differential charge density and optoelectronic properties of undoped and Si doped β-Ga2O3 are calculated using GGA+U method based on density functional theory. The results show that the Si-substituted tetrahedron Ga(1) is more easily synthesized in experiments, and the obtained β-Ga2O3 band gap and Ga 3d state peak are in good agreement with the experimental results, and the effective doping is more likely to be obtained under oxygen-poor conditions. After Si doping, the total energy band moves to the low-energy end, and Fermi level enters the conduction band, showing n-type conductive characterastic. Si 3s orbital electrons occupy the bottom of the conduction band, the degree of electronic coocupy is strengthened, and the conductivity is improved. The dielectric function ε2(ω) results show that with the increase of Si doping concentration, the ability to stimulate conductive electrons first increases and then decreases, which is in good agreement with the quantitative analysis results of conductivity. The optical band gap increases and the absorption band edge rises slowly with the increase of Si doping concentration. The results of absorption spectra show that Si-doped β-Ga2O3 has strong deep ultraviolet photoelectric detection ability. The calculated results provide a theoretical reference for the further experimental investigation and the optimization innovation of Si-doped β-Ga2O3 and relative device design.