How silicene on Ag(111) oxidizes: microscopic mechanism of the reaction of O2 with silicene.

ABSTRACT: We demonstrate, using first-principles molecular-dynamics simulations, that oxidation of silicene can easily take place either at low or high oxygen doses, which importantly helps clarify previous inconsistent reports on the oxidation of silicene on the Ag(111) substrate. We show that, while the energy barrier for an O2 molecule reacting with a Si atom strongly depends on the position and orientation of the molecule, the O2 molecule immediately dissociates and forms an Si-O-Si configuration once it finds a barrier-less chemisorption pathway around an outer Si atom of the silicene overlayer. A synergistic effect between the molecular dissociation and subsequent structural rearrangements is found to accelerate the oxidation process at a high oxygen dose. This effect also enhances self-organi

SUBMITTER: Morishita T 

PROVIDER: S-EPMC4668378 | biostudies-literature | 2015 Dec

REPOSITORIES: biostudies-literature