Effect of Selenium Doping on the Electronic Properties of β-Ga2O3 by First-Principles Calculations

This study is the first to explore the effect of selenium doping on the electronic properties of beta-Ga2O3 through first-principles calculations. Selenium doping in beta-Ga2O3 is a significant choice, as it has the potential to improve the material's electronic properties. Previous work on beta-Ga2O3 has focused primarily on other dopants, and the effect of selenium doping is not well understood. Therefore, this study fills an important gap in the current understanding of beta-Ga2O3 doping. Selenium doping in beta-Ga2O3 was studied by first-principles calculations with a hybrid functional, as this functional can offer a more accurate description of electronic properties, resulting in accurate electronic bandgap and defect level calculations. Our first-principles calculations reveal that selenium can be incorporated on both Ga and O sites under specific conditions. Specifically, under O-rich conditions, selenium atoms are more likely to substitute the Ga sites, whereas under Ga-rich conditions, they are more likely to substitute the O sites. With the formation energy analysis, our findings indicate that selenium doping on Ga sites can lead to n-type conductivity, with it acting as shallow donor. On the other hand, Se dopants at the O sites exhibit deep donor characteristics, rendering it ineffective in regulating the conductivity of beta-Ga2O3 materials. Our findings suggest that Se can be used as a dopant to tune the beta-Ga2O3 conductivity for electronic and photonic applications, provided that the atomic substitution on Ga sites can be effectively controlled. Our results will provide valuable theoretical insights for the refined use of selenium dopants in beta-Ga2O3, as well as guidance and theoretical support for subsequent researchers in the selection of Ga2O3 dopants.