Theoretical research of TiO2 adsorption on GaN(0001) surface

Abstract

The adsorption of molecule TiO2 on GaN(0001) surface is theoretically explored by using a plane wave ultrasoft pseudo-potential method based on the density functional theory. The bonding processing of TiO2molecule on the surface of GaN(0001), the adsorption energy, and the adsorption orientation are investigated. The results indicate that Ti atom is adsorbed on fcc site or on hcp site, and two O atoms are combined with two Ga atoms on the GaN surface after adsorption. The chemical bonding of GaO shows a covalent feature, and the chemical bonding energy is achieved to be 7.9327.943 eV. The OO line directions lie along the GaN [1120] directions, in accordance with experimental reports of (100) [001] TiO2// (0001)[1120] GaN. From ab initio dynamics calculation, the adsorption process can be divided into physical adsorption, chemical adsorption and superficial stable state,and the stable adsorption site is in accordance with the optimized results.