《厦门大学学报（自然科学版）》

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.

引言
1 理论方法
2 计算模型
3 计算结果与分析
4 结论

图1 ZnO 的3×3×2超晶胞结构<br/>Fig.1 ZnO 3×3×2 supercell structure

图1 ZnO 的3×3×2超晶胞结构
Fig.1 ZnO 3×3×2 supercell structure

表1 ZnO1-x的总能量与结构参数<br/>Tab.1 Total energies and structure parameters of ZnO1-x

表1 ZnO1-x的总能量与结构参数
Tab.1 Total energies and structure parameters of ZnO1-x

表2 当O原子化学势和费米能级取极限值时ZnO中不同氧空位的形成能<br/>Tab.2 The oxygen vacancy distribution formation energies in ZnO for the chemical potentials of oxygen atom and Fermi levels at limited values

表2 当O原子化学势和费米能级取极限值时ZnO中不同氧空位的形成能
Tab.2 The oxygen vacancy distribution formation energies in ZnO for the chemical potentials of oxygen atom and Fermi levels at limited values

图2 富氧条件(μo=μ0o)下不同氧空位形成能与费米能级的关系<br/>Fig.2 Different oxygen vacancy formation energies as a function of Fermi level for μo=μ0o

图2 富氧条件(μo=μ0o)下不同氧空位形成能与费米能级的关系
Fig.2 Different oxygen vacancy formation energies as a function of Fermi level for μo=μ0o

图3 富锌条件(μo=μ0o+ΔEZnOf)下不同氧空位形成能与费米能级的关系<br/>Fig.3 Different oxygen vacancy formation energies as a function of Fermi level for μo=μ0o+ΔEZnOf

图3 富锌条件(μo=μ0o+ΔEZnOf)下不同氧空位形成能与费米能级的关系
Fig.3 Different oxygen vacancy formation energies as a function of Fermi level for μo=μ0o+ΔEZnOf

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备注

引言

1 理论方法

2 计算模型

3 计算结果与分析

4 结论

学报简介

备注

引言

1 理论方法

2 计算模型

3 计算结果与分析

4 结 论

学报简介

4 结论