Theoretical calculation on the reaction of alkene molecules on H-terminated Si(100)-3×1 surface

Abstract

A study on mechanisms of radical initiated surface chain reaction of ethylene molecule on H-terminated Si(100)-3 × 1 has been carried out in a supercell approach by using density functional theory and ab initio molecular dynamic method. On the H-terminated Si(100)-3 × 1 surface, one of the crucial steps of the surface chain reaction, namely, the abstraction of a H atom from a nearby surface hydride unit, is found to have a somewhat smaller activation energy from the nearest silicon site than from the next-nearest silicon site. From the intermediate state to the final state, the transition state has bigger activation energy. Ab initio molecular dynamics (MD) shows that the H-abstraction on Si(100)-3 × 1 surface bound organic group with a carbon-centered radical is very easy to be obtained from the transition state, and it also shows that the C…H bond at methyl group is formed in a very short MD time, and the Si…C bond between the Si surface and the alkyl chain oscillates with time evolution on Si(100)-3 × 1 surface.