Investigation of electronic structure and optoelectronicproperties of Si-doped -Ga2O3using GGA+Umethod based on first-principle

In this work, the formation energy, band structure, state density, differential charge density andoptoelectronic properties of undoped beta-Ga2O3 and Si doped beta-Ga2O3 are calculated by using GGA+U methodbased on density functional theory. The results show that the Si-substituted tetrahedron Ga(1) is more easilysynthesized experimentally, and the obtained beta-Ga2O3 band gap and Ga-3d state peak are in good agreementwith the experimental results, and the effective doping is more likely to be obtained under oxygen-poorconditions. After Si doping, the total energy band moves toward the low-energy end, and Fermi level enters theconduction band, showing n-type conductive characteristic. The Si-3s orbital electrons occupy the bottom of theconduction band, the degree of electronic occupancy is strengthened, and the conductivity is improved. Theresults from dielectric function epsilon 2(omega) show that with the increase of Si doping concentration, the ability tostimulate conductive electrons first increases and then decreases, which is in good agreement with thequantitative analysis results of conductivity. The optical band gap increases and the absorption band edge risesslowly with the increase of Si doping concentration. The results of absorption spectra show that Si-doped beta-Ga2O3 has the ability to realize the strong deep ultraviolet photoelectric detection. The calculated resultsprovide a theoretical reference for further implementing the experimental investigation and the optimizationinnovation of Si-doped beta-Ga2O3 and relative device design