| Affiliation: | (1) Institute of Microelectronics and Solid State Electronics, University of Electronic Science and Technology of China, 610054 Chengdu, China;(2) Institute of Mathematics and Software Science, Sichuan Normal University, 610068 Chengdu, China;(3) Institute of Chemical Materials, China Academy of Engineering Physics, 621000 Mianyang, China |
| Abstract: | ZnO adsorption on sapphire (0001) surface is theoretically calculated by using a plane wave ultrasoft pseudo-potential method based onab initio molecular dynamics. The results reveal that the surface relaxation in the first layer Al-O is reduced, even eliminated after the surface adsorption of ZnO, and the chemical bonding energy is 434.3(±38.6) kJ · mol−1. The chemical bond of ZnO (0.185 ± 0.01 nm) has a 30° angle away from the adjacent, Al-O bond, and the stable chemical adsorption position of the Zn is deflected from the surface O-hexagonal symmetry with an angle of about 30°. The analysis of the atomic populations, density of state and bonding electronic density before and after the adsorption indicates that the chemical bond formed by the O2− of the ZnO and the surface Al3+ has a strong ionic bonding characteristic, while the chemical bond formed by the Zn2+ and the surface O2− has an obvious covalent characteristic, which comes mainly from the hybridization of the Zn 4s and the O 2p and partially from that of the Zn 3d and the O 2p. |
