Surface doping of MoO_3-xon hydrogenated diamond

Surface doping is reported to be a potential solution for diamond, which is known hard to be doped traditionally for high power electronics applications. While MoO₃ was found to be an effective surface electron acceptor for hydrogen-terminated diamond with negative electron affinity, the effects of commonly existing oxygen vacancies remain elusive. We performed reactive molecular dynamics simulations to study the deposition of MoO_3-x on hydrogenated diamond (111) surface and used first-principles calculations based on density functional theory to investigate the change transfer and electronic structures. Shift of the electronic band alignment is observed. Bader charge calculations show that MoO_3-x are effective surface electron acceptor materials, where more electrons are transferred with increased O stoichiometry. The charge density difference after the deposition is used to characterize the spatial extent of doped holes.