title: Adsorption of atomic nitrogen and oxygen on [Formula: see text] surface: a density functional theory study.
abstract: The adsorption of atomic nitrogen and oxygen on the ([Formula: see text]) crystal face of zinc oxide (ZnO) was studied. Binding energies, workfunction changes, vibrational frequencies, charge density differences and electron localization functions were calculated. It was elucidated that atomic oxygen binds more strongly than nitrogen, with the most stable [Formula: see text] structure exhibiting a binding energy of -2.47 eV, indicating chemisorption onto the surface. Surface reconstructions were observed for the most stable minima of both atomic species. Positive workfunction changes were calculated for both adsorbed oxygen and nitrogen if the adsorbate interacted with zinc atoms. Negative workfunction changes were calculated when the adsorbate interacted with both surface oxygen and zinc atoms. Interactions between the adsorbate and the surface zinc atoms resulted in ionic-type bonding, whereas interactions with oxygen atoms were more likely to result in the formation of covalent-type bonding. The positive workfunction changes correlate with an experimentally observed increase in resistance of ZnO conductometric sensor devices.
authors.affiliation: Applied Physics, School of Applied Sciences, RMIT University, GPO Box 2476V, Vic 3001, Australia. School of Electrical and Computer Engineering, RMIT University, GPO Box 2476V, Vic 3001, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Breedon
authors.forename: M J S
authors.initials: MJ
authors.lastname: Spencer
authors.forename: I
authors.initials: I
authors.lastname: Yarovsky