高等学校化学学报 ›› 2016, Vol. 37 ›› Issue (5): 932-937.doi: 10.7503/cjcu20150973

• 物理化学 • 上一篇    下一篇

ZnO和ZnS本征点缺陷的理论研究

马昌敏, 刘廷禹(), 常秋香, 罗国胤   

  1. 上海理工大学理学院, 上海 200093
  • 收稿日期:2015-12-23 出版日期:2016-05-10 发布日期:2016-04-20
  • 作者简介:联系人简介: 刘廷禹, 男, 博士, 教授, 主要从事晶体点缺陷研究. E-mail:liutyyxj@163.com
  • 基金资助:
    沪江基金项目(批准号: B14004)资助

Theoretical Studies on the Intrinsic Defects in ZnO and ZnS Crystal

MA Changmin, LIU Tingyu*(), CHANG Qiuxiang, LUO Guoyin   

  1. College of Science, University of Shanghai for Science and Technology, Shanghai 200093, China
  • Received:2015-12-23 Online:2016-05-10 Published:2016-04-20
  • Contact: LIU Tingyu E-mail:liutyyxj@163.com
  • Supported by:
    † Supported by the Foundation of Hujiang, China(No;B14004)

摘要:

基于第一性原理和热动力学方法, 通过模拟计算分析了不同温度和分压下ZnS和ZnO晶体本征点缺陷的性质. 振动熵的计算结果表明, 在高温条件下, 振动熵对缺陷形成能的贡献不能忽略. 对比分析2种晶体本征点缺陷随环境条件变化的规律, 结果表明, 2种晶体的主导缺陷均为空位型. 氧空位(VO)在ZnO中更易形成, 富氧和低温条件有利用于ZnO的p型本征掺杂. 而锌空位(VZn)在ZnS中形成能最低, 因此ZnS比ZnO更容易形成p型掺杂. 研究还发现2种晶体的肖特基缺陷都不稳定, 而弗伦克尔缺陷比较稳定. 除ZnS反弗伦克尔缺陷外, 有价态的缺陷对的形成能均比中性缺陷对的形成能低.

关键词: 密度泛函理论, 点缺陷, 热力学, 氧化锌, 硫化锌

Abstract:

The stability of the intrinsic point defects in ZnS and ZnO crystal over a range of temperature and the partial pressure pS2 and pO2 was studied with the approach that integrates first-principles, thermodynamic calculations and the contributions of vibrational entropy. The results indicate that the contribution of the vibrational entropy to the defect formation energy could not be ignored under high temperature condition. The vacancy-type defects are the predominant intrinsic point defects in ZnS and ZnO crystal. The anion vacancy(VO) forms more easily in ZnO crystal, however, the VZn has the lowest formation energy in ZnS under most conditions. Therefore, ZnS crystal is easier to perform p-type doping than ZnO crystal. The defect formation energies of the complex point defect, including Frenkel pairs, anti-Frenkel pairs and Schottky pairs, were calculated to predict relative stability. The calculated results show that the Schottky defect pairs are the most unstable, the Frenkel defect pairs are the most stable. Except anti-Frenkel pairs in ZnS, the combinations of charged defects produce lower defect formation energies than combinations of neutral defects.

Key words: Density functional theory(DFT), Point defect, Thermodynamics, ZnO, ZnS

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