Reaction mechanisms of low-kinetic energy hydrocarbon radicals on typical hydrogenated amorphous carbon (a-C:H) sites: A molecular dynamics study

In this work, we have investigated reaction mechanisms of several hydrocarbon radicals on specific sites, relevant for a-C:H thin films. This study has been carried out using classical molecular dynamics simulations. The species whose reaction mechanisms have been studied, include C2, C3, linear C3H and cyclic C3H. In total, 9 surface sites have been investigated. Several trends in the mechanisms have been established. It is shown that chemical resonance, steric hindrance and structural stability are the main factors affecting the reaction mechanisms. Also, the influence of site-specific factors is addressed. This information is important for a better understanding of the growth of thin a-C:H films from low-kinetic energy hydrocarbons.