Study of first-principle about water and N2 adsorption on the non-doped and nitrogen-doped diamond (111) surface

Abstract

The performance of diamond is usually closely related to the work environment. However, many researches focus on the relationship between non-doped or hydrogen-doped surfaces and the environment. We investigate the adsorption of N2 and water on non-doped and nitrogen-doped surface using first-principles calculations. The results show that, nitrogen-doped surface can inhibit the spin polarization after adsorption of water, although weak covalent chemical adsorption also occurs on the nitrogen-doped surface. However, the spin polarization phenomenon is obvious when nitrogen is adsorbed perpendicular to the nitrogen-doped surface, although only physical adsorption exists between nitrogen and two kinds of surface. Our results demonstrate the electron spin stability of nitrogen-doped diamonds in humid environments, which is helpful for application of diamond in electron spin devices. In addition, our results provide a microscopic description of the adsorption of N2 and water on non-doped surface, which is helpful for studying the conductivity of diamond in air.