中国物理B ›› 2018, Vol. 27 ›› Issue (5): 57701-057701.doi: 10.1088/1674-1056/27/5/057701

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Effect of O-O bonds on p-type conductivity in Ag-doped ZnO twin grain boundaries

Jingjing Wu(吴静静), Xin Tang(唐鑫), Fei Long(龙飞), Biyu Tang(唐壁玉)   

  1. 1 Key Laboratory of New Processing Technology for Nonferrous Metal & Materials, Ministry of Education, Guilin University of Technology, Guilin 541004, China;
    2 College of Material Science and Engineering, Guilin University of Technology, Guilin 541004, China;
    3 School of Chemistry & Chemical Engineering, Guangxi University, Nanning 530004, China
  • 收稿日期:2017-11-26 修回日期:2018-02-23 出版日期:2018-05-05 发布日期:2018-05-05
  • 通讯作者: Xin Tang E-mail:xtang@glut.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No.11364009) and Natural Science Foundation of Guangxi Province,China (Grant No.2014GXNSFFA118004).

Effect of O-O bonds on p-type conductivity in Ag-doped ZnO twin grain boundaries

Jingjing Wu(吴静静)1,2, Xin Tang(唐鑫)1,2, Fei Long(龙飞)1,2, Biyu Tang(唐壁玉)3   

  1. 1 Key Laboratory of New Processing Technology for Nonferrous Metal & Materials, Ministry of Education, Guilin University of Technology, Guilin 541004, China;
    2 College of Material Science and Engineering, Guilin University of Technology, Guilin 541004, China;
    3 School of Chemistry & Chemical Engineering, Guangxi University, Nanning 530004, China
  • Received:2017-11-26 Revised:2018-02-23 Online:2018-05-05 Published:2018-05-05
  • Contact: Xin Tang E-mail:xtang@glut.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No.11364009) and Natural Science Foundation of Guangxi Province,China (Grant No.2014GXNSFFA118004).

摘要: Based on density functional theory, first-principles calculation is applied to study the electronic properties of undoped and Ag-doped ZnO-Σ7 (1230) twin grain boundaries (GBs). The calculated result indicates that the twin GBs can facilitate the formation and aggregation of Ag substitution at Zn sites (AgZn) due to the strain release. Meanwhile, some twin GBs can also lower the ionization energy of AgZn. The density of state shows that the O-O bonds in GBs play a key role in the formation of a shallow acceptor energy level. When AgZn bonds with one O atom in the O-O bond, the antibonding state of the O-O bond becomes partially occupied. As a result, a weak spin splitting occurs in the antibonding state, which causes a shallow empty energy level above the valence band maximum. Further, the model can be applied to explain the origin of p-type conductivity in Ag-doped ZnO.

关键词: ZnO, twin grain boundary, first-principles calculation, ligand field theory

Abstract: Based on density functional theory, first-principles calculation is applied to study the electronic properties of undoped and Ag-doped ZnO-Σ7 (1230) twin grain boundaries (GBs). The calculated result indicates that the twin GBs can facilitate the formation and aggregation of Ag substitution at Zn sites (AgZn) due to the strain release. Meanwhile, some twin GBs can also lower the ionization energy of AgZn. The density of state shows that the O-O bonds in GBs play a key role in the formation of a shallow acceptor energy level. When AgZn bonds with one O atom in the O-O bond, the antibonding state of the O-O bond becomes partially occupied. As a result, a weak spin splitting occurs in the antibonding state, which causes a shallow empty energy level above the valence band maximum. Further, the model can be applied to explain the origin of p-type conductivity in Ag-doped ZnO.

Key words: ZnO, twin grain boundary, first-principles calculation, ligand field theory

中图分类号:  (ZnO)

  • 77.55.hf
61.72.Mm (Grain and twin boundaries) 63.20.dk (First-principles theory) 71.70.Ch (Crystal and ligand fields)