(1.闽南师范大学物理与信息工程学院,福建 漳州 363000; 2.厦门大学物理科学与技术学院,福建 厦门 361005)

第一性原理计算; ZnO; 氧空位; 形成能

First-principles Studies on the Formation Energy of Oxygen Vacancies in ZnO
LIN Chuanjin1,2,ZHU Zizhong2*

(1.College of Physics and Information Engineering,Minnan Normal University,Zhangzhou 363000,China; 2.College of Physical Science and Technology,Xiamen University,Xiamen 361005,China)

first-principles calculations; ZnO; oxygen vacancy; formation energy

DOI: 10.6043/j.issn.0438-0479.201611009


采用基于密度泛函理论的第一性原理方法,研究了ZnO在富氧和富锌条件下氧的单空位、双空位和三空位缺陷的形成能.结果表明:在富氧和富锌条件下,随着氧空位浓度的增加,氧空位形成能变大,说明ZnO中不容易产生多空位氧缺陷; 随着氧空位浓度的增加,氧空位对应的吸收光谱红移; 分散型氧双空位的形成能低于聚集型氧双空位,说明ZnO中不容易产生氧空位聚集,由此可解释ZnO的抗辐照能力; 在富锌条件下,聚集型氧双空位的形成能大于分散型氧三空位的形成能,说明在此条件下聚集型氧双空位更难形成.

The studies on the distribution of single- and multi-vacancies of oxygen in ZnO are helpful in understanding the mechanism of the n-type conductivity of native ZnO material as well as the abilities of the radiation resistance of ZnO.In this paper,we employed the first-principles method based on the density functional theory to determine the formation energies of monovacancy,divacancies and trivacancies of oxygen in bulk ZnO under both O-rich and Zn-rich conditions.The results show that,under both O-rich and Zn-rich conditions,the formation energies of oxygen vacancy increase as the concentration of oxygen vacancy increase,indicating that it is difficult to form multi-vacancies of oxygen in bulk ZnO.With the increase of the concentration of oxygen vacancies,the absorption spectra of oxygen vacancies show red shift.For the oxygen divacancies in ZnO,the formation energy of separated oxygen vacancies is lower than that of gathered oxygen vacancies,indicating that it is not easy to produce oxygen vacancy aggregation in ZnO,which is able to explain the radiation hardness properties of ZnO.Under the Zn-rich condition,the formation energy of gathered divacancies of oxygen is greater than that of separated trivacancies,showing that oxygen vacancies are more difficult to gather under the Zn-rich condition.