Adsorption Properties of the C(100)-(2×1) Diamond Surface with Vacancy Defects and “Nitrogen + Vacancy” Complexes

Abstract

The results are presented from the quantum-chemical modeling of hydrogen chemisorption on a C(100)-(2×1) diamond surface that contains the most stable neutral monovacancies and negatively charged “nitrogen + vacancy” defects in the surface layers. The configurations of molecular orbitals are analyzed for the studied defects. It is found that a vacancy in the third layer and a “vacancy in the third layer, nitrogen in the fourth layer” complex alter the values of the activation energy and the heat of hydrogen chemisorption on the surface. The most active adsorption centers are represented by the atoms of the first and second layers located directly above the NV complex in the singlet state. The chemisorption of hydrogen on the same defect in the triplet state is the most complicated of the considered cases.