Title :
The thermally stimulated current in zinc oxide varistors with TiO 2 additives
Author :
Lee, Joon-Ung ; Chang, Kyung-Ook ; Park, Choon-Bae ; Grzybowski, S.
Author_Institution :
Dept. of Electr. Eng., Kwangwoon Univ., Seoul, South Korea
Abstract :
To contribute more information on the conduction mechanism in ZnO varistors, a study of ZnO varistors with TiO2 additives was conducted. The properties of ZnO varistors are found to depend on the grain structure of ZnO. The mechanism of nonlinear conduction of ZnO may be explained on the basis of the grain structure. The TSC (thermally stimulated current) spectrum was measured to study the trapped carriers in ZnO varistors. Four peaks of TSC may be distinguished on the spectrum of TSC. The origin of the first, second, and third TSC peaks was attributed to the detrapping of the trapped electrons in the shallow trap, donor level, and deep trap, respectively. The origin of the fourth peak was attributed to the process of depolarization of the donor ions in the depleted layer. Adding TiO2 to ZnO varistors caused the leakage current to increase
Keywords :
ceramics; crystal microstructure; electrical conductivity of crystalline semiconductors and insulators; electron traps; leakage currents; semiconductor materials; titanium compounds; varistors; zinc compounds; TiO2 additives; ZnO varistors; ZnO-TiO2; conduction mechanism; deep trap; depleted layer; depolarization; detrapping; donor ion depolarisation; donor level; grain structure; leakage current; nonlinear conduction; semiconductors; shallow trap; thermally stimulated current; trapped carriers; Additives; Ceramics; Electron traps; Equations; Fabrication; Low voltage; Temperature dependence; Temperature distribution; Varistors; Zinc oxide;
Conference_Titel :
Properties and Applications of Dielectric Materials, 1991., Proceedings of the 3rd International Conference on
Conference_Location :
Tokyo
Print_ISBN :
0-87942-568-7
DOI :
10.1109/ICPADM.1991.172107
