表面氧空位浓度对ZnO性质影响的第一性原理研究

he effects of different surface oxygen vacancy concentration in the structural stability, the electronic structure and optical properties of ZnO (10-10) surface system were studied using DFT methods. The results showed that the structural stability of the systems with oxygen vacancy concentration of 4.17% was better than that 2.08% system. When the surface with oxygen vacancies, the Fermi level moved to the high energy level, a defect energy level occurs in the band gap, and the Fermi level and defect energy levels have some overlap. In addition, the greater the concentration of oxygen vacancies, the defect energy levels accounted for the wide energy range and delocalized more obviously, which was conducive to the movement of electrons. Moreover, the oxygen vacancies leaded to a reduced of band gap and reduced the distance of electrons to the conduction band. As a result, the photocatalytic efficiency of the system had been improved. For the absorption spectrum, with the concentration of oxygen vacancies increased, the absorption coefficient in ultraviolet and visible light region were increasing, which means that the utilization of solar energy improved. In this paper, calculations were promising for evidence the Experimental Research of ZnO with oxygen vacancies.