中国物理B ›› 2012, Vol. 21 ›› Issue (9): 97201-097201.doi: 10.1088/1674-1056/21/9/097201

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

Physical meaning of conductivity spectra for ZnO ceramics

成鹏飞a, 李盛涛b, 李建英b, 丁璨b, 杨雁b   

  1. a School of Science, Xi'an Polytechnic University, Xi'an 710048, China;
    b State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049, China
  • 收稿日期:2012-01-11 修回日期:2012-03-03 出版日期:2012-08-01 发布日期:2012-08-01
  • 基金资助:
    Project supported by the Scientific Research Plan of the Education Department of Shaanxi Province, China (Grant No. 12JK0434) and the Doctoral Scientific Research Foundation, China (Grant No. BS0814).

Physical meaning of conductivity spectra for ZnO ceramics

Cheng Peng-Fei (成鹏飞)a, Li Sheng-Tao (李盛涛)b, Li Jian-Ying (李建英)b, Ding Can (丁璨)b, Yang Yan (杨雁)b   

  1. a School of Science, Xi'an Polytechnic University, Xi'an 710048, China;
    b State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049, China
  • Received:2012-01-11 Revised:2012-03-03 Online:2012-08-01 Published:2012-08-01
  • Contact: Cheng Peng-Fei E-mail:pfcheng@xpu.edu.cn
  • Supported by:
    Project supported by the Scientific Research Plan of the Education Department of Shaanxi Province, China (Grant No. 12JK0434) and the Doctoral Scientific Research Foundation, China (Grant No. BS0814).

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摘要： With the help of broadband dielectric spectroscopy in a wide temperature and frequency range, conductivity spectra of ZnO polycrystalline ceramics are measured and direct-current-like (DC-like) conductivity and relaxation polarization conductivity are observed successively along the frequency axis. According to classical Debye theory and Cole-Cole equation, the physical meanings of the two conductivities are discussed. It is found that the DC-like conductivity corresponds to electron transportation over Schottky barrier at grainboundary. The relaxation polarization conductivity corresponds to electronic trap relaxation of intrinsic point defects (zinc interstitial and oxygen vacancy). When it is in the high frequency region, relaxation conductivity obeys the universal law with the index n equal to the index α in Cole-Cole equation as an indictor of disorder degree.

关键词: ZnO ceramics, conductivity spectra, Schottky barrier, relaxation polarization

Abstract: With the help of broadband dielectric spectroscopy in a wide temperature and frequency range, conductivity spectra of ZnO polycrystalline ceramics are measured and direct-current-like (DC-like) conductivity and relaxation polarization conductivity are observed successively along the frequency axis. According to classical Debye theory and Cole-Cole equation, the physical meanings of the two conductivities are discussed. It is found that the DC-like conductivity corresponds to electron transportation over Schottky barrier at grainboundary. The relaxation polarization conductivity corresponds to electronic trap relaxation of intrinsic point defects (zinc interstitial and oxygen vacancy). When it is in the high frequency region, relaxation conductivity obeys the universal law with the index n equal to the index α in Cole-Cole equation as an indictor of disorder degree.

Key words: ZnO ceramics, conductivity spectra, Schottky barrier, relaxation polarization

中图分类号:  (Conductivity phenomena in semiconductors and insulators)

  • 72.20.-i
73.30.+y (Surface double layers, Schottky barriers, and work functions) 77.22.Gm (Dielectric loss and relaxation) 77.55.hf (ZnO)