Electronic properties of monoclinic (InxGa1-x)2O3 alloys by first-principle

We report on the electronic properties of β-(InxGa1-x)2O3 alloys with different In-content up to 18.75% using density functional theory (DFT) calculations. The effect of In-content on the band structures as well as the crystal structures of β-(InxGa1-x)2O3 alloys is presented and discussed. Our analysis shows that β-(InxGa1-x)2O3 alloys exhibits indirect gap property, with the band gap reducing from 4.817 eV to 4.422 eV when the In-content increases up to 18.75%. The bandgap energy corresponds to the wavelength region extending from 255 to 280 nm, which implies the possibility for β-(InxGa1-x)2O3 alloys to be applied in the deep UV photodetectors. The electron and heavy hole effective masses are also obtained for the first time based on the band edge dispersions of the β-(InxGa1-x)2O3 materials. Additionally, the effect of band parameters on the impact ionization processes using β-(InxGa1-x)2O3 materials are analyzed. Our new insight regarding the electronic properties indicate the potential of β-(InxGa1-x)2O3 alloys in deep ultraviolet photodetector applications.