论文部分内容阅读
建立了一种 2× 2α Al2 O3 (0 0 0 1)基片表面吸附ZnO模型 ,在周期边界条件下的k空间中 ,采用基于密度泛函理论的局域密度近似平面波超软赝势法 ,对α Al2 O3 (0 0 0 1)基片表面结构及其ZnO分子在表面最初吸附生长位置进行了计算研究。由于较大的表面弛豫 ,使得氧原子全部暴露于基片最外表面 ,明显地表现出O原子电子表面态 ;驰豫后的表面能对ZnO分子产生较强的化学吸附 ,表面电子结构将发生明显的变化 ,其表面最优吸附生长点的方位正好偏离α Al2 O3 (0 0 0 1)表面氧六角对称 30° ;并计算了这些吸附生长点处Zn与表面O的结合能。
A model of ZnO adsorbed on the surface of 2 × 2α Al 2 O 3 (0 0 0 1) substrate was established. In the k-space under the periodic boundary conditions, the local density approximation plane wave super soft pseudopotential method based on density functional theory The surface structure of α Al 2 O 3 (0 0 0 1) substrate and the initial position of ZnO molecules on the surface were calculated. Due to the large surface relaxation, all the oxygen atoms are exposed on the outermost surface of the substrate, which obviously shows the O atom electronic surface state. The relaxed surface energy has a strong chemisorption on the ZnO molecules. The surface electronic structure , The azimuthal orientation of the optimal adsorption growth point on the surface just deviates from the symmetry of oxygen hexagonal at α 0 0 0 0 (0 0 0 1) by 30 °. The binding energies of Zn and surface O at these adsorption sites are calculated.