Microstructure and electrical properties of La₂O₃-doped ZnO-based varistor thin films by sol-gel process

Abstract

Microstructure and electrical properties of La₂O₃-doped ZnO-Bi₂O₃ thin films prepared by sol-gel process have been investigated. X-ray diffraction shows that most diffraction peaks of ZnO are equal, and the crystals of ZnO grow well. Scanning electron microscopy and atomic force microscopy results indicate that the samples have a good structure and lower surface roughness. The nonlinear V-I characteristics of the films show that La₂O₃ develops the electrical properties largely and the best doped content is 0.3% lanthanum ion, with the leakage current of 0.25 mA, the threshold field of 150 V/mm and the nonlinear coefficient of 4.0 in detail.

Keywords

zinc oxide / varistor / film / sol-gel process / electrical properties / microstructure

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