Strong selective oxidization on two-dimensional GaN: a first principles study

Ab initio calculations were performed to investigate the chemical oxidation of two-dimensional (2D) gallium nitride (GaN). The nitrogen surface was found to form a metastable configuration under oxygen adsorption, while the gallium surface could be readily transformed to a more stable configuration of HO-GaN-H with an exceptionally low energy barrier. The results also revealed that the adsorption of oxygen adatoms resulted in the reduction of work-function and induced the change from 2D GaN to a new GaNO compound. Our findings indicate that we should pay attention to the oxidation effect of 2D GaN in practical device applications.