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表面氧空位浓度对ZnO性质影响的第一性原理研究

发表时间:2016-01-15  浏览量:2276  下载量:1162
全部作者: 黄萍,商波,李凌杰,雷惊雷
作者单位: 重庆大学化学化工学院
摘 要: 使用密度泛函理论(density functional theory,DFT)方法研究不同表面氧空位浓度对ZnO(10-10)表面体系的结构稳定性、电子结构和光学性质的影响。计算结果表明,表面氧空位浓度为4.17%的体系结构稳定性比氧空位浓度为2.08%的体系结构稳定性更好。当表面引入氧空位后,费米能级向高能级方向移动,在带隙中出现了缺陷能级,缺陷能级与费米能级有部分重合,并且氧空位浓度越大,缺陷能级所占的能量范围越广,非局域化更明显,有利于电子的自由移动。此外,由于氧空位的存在,导致体系的带隙缩小,提高了光催化效率。在吸收光谱中,氧空位浓度越大,紫外和可见光的吸收系数均增大,说明材料对光能的利用率提高。本文的理论计算结果有望为含氧空位的ZnO光催化性实验研究提供依据。
关 键 词: 物理化学;ZnO;密度泛函理论;缺陷形成能;电子结构;光学性质
Title: First-principles study on the effects of surface oxygen vacancy concentration on the properties of ZnO
Author: HUANG Ping, SHANG Bo, LI Lingjie, LEI Jinglei
Organization: College of Chemistry and Chemical Engineering, Chongqing University
Abstract: The 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 density functional theory (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 occured in the band gap, and the Fermi level and defect energy levels had 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 led to a reduced band gap. As a result, the photocatalytic efficiency of the system had been improved. For the absorption spectrum, with the concentration of oxygen vacancies increasing, the absorption coefficient in ultraviolet and visible light region increased, which means that the utilization of solar energy improved. In this paper, calculations were promising for the evidence of the experimental research of ZnO with oxygen vacancies.
Key words: physical chemistry; ZnO; density functional theory; vacancy formation energy; electronic structure; optical properties
发表期数: 2016年1月第1期
引用格式: 黄萍,商波,李凌杰,等. 表面氧空位浓度对ZnO性质影响的第一性原理研究[J]. 中国科技论文在线精品论文,2016,9(1):32-38.
 
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