Surface conductivity of hydrogenated diamond films

The experimentally observed high surface conductivity of hydrogenated diamond films is explained through ab initio results as well as model calculations based on the tight-binding molecular dynamics method. Our results support the previously reported experimental results indicating that the surface conductivity of the hydrogenated diamond surfaces is due to the surface adsorption of a H3O+ monolayer. Specifically, it is shown that the presence of the H3O+ adlayer results in the formation of an electrostatic surface dipole moment which makes the potential of the surface H layer effectively more attractive. This, in turn, ignites charge transfer from the diamond lattice to the surface layer creating, thus, the necessary charge carriers (holes) for the observed high conductivity.