First-Principles Study on the Electronic Structure and Optical Properties of α-(AlxGa1-x)2O3 Alloys

Abstract

The study focuses on exploring the exceptional electronic and optical properties of the α-(AlxGa1-x)2O3 alloys (AlGaO) using advanced density functional theory (DFT) with hybrid functional methods. By varying the Al content (x) from 0 to 1, the bandgap expands from 5.288 eV to 8.819 eV while maintaining its direct nature. The incorporation of Al significantly enhances the material’s ability to absorb high-energy ultraviolet-light, particularly in the deep ultraviolet region (wavelength < 200 nm), due to the strong covalent nature of Al-O bonds and the widened conduction band. The absorption spectra exhibit a distinct shift toward higher energies as the Al ratio increases, accompanied by pronounced optical anisotropy along the x and z crystallographic directions. These characteristics highlight the alloy’s flexible tunability, making it an ideal candidate for advanced applications such as ultraviolet band-C (UVC) sensors, germicidal light sources, and anti-reflective coatings. This study not only provides a solid theoretical foundation for optimizing α-(AlxGa1-x)2O3 as a versatile wide-bandgap semiconductor but also paves the way for future experimental studies to fully unlock its potential in next-generation electronic and optoelectronic devices.