Role of hydrogen in gallium oxide

The properties of gallium oxide make it particularly suitable for applications in power electronics. Hydrogen is often present during growth or processing of the material; in fact, in the widely used technique of metal-organic chemical vapor deposition (MOCVD) hydrogen is present in the metal-organic precursors and often used as a carrier gas. It is therefore important to assess the impact of hydrogen on growth and on the properties of Ga₂O₃ and related alloys. We address these issues using first-principles calculations based on density functional theory. Our comprehensive study of surface reconstructions establishes under which conditions hydrogen will be present on the surface, and how it will affect the growth. For hydrogen that gets incorporated in the material, we calculate diffusion barriers, which turn out to be highly anisotropic [1]. Hydrogen can also interact with intentional or unintentional impurities; I will discuss hydrogen passivation of dopants, and also address complex formation with carbon, another impurity that is easily incorporated during MOCVD growth.



[1] S. Mu, M. Wang, J. B Varley, J. L Lyons, D. Wickramaratne, and C. G. Van de Walle, Phys. Rev. B 105, 155201 (2022).