YANG Liyu, REN Xin, NING Yu, LIU Xiaoman, GAO Li, YOU Junwei, YAO Zheng
(Nano-Science and Technology Research Center, College of Sciences, Shanghai University, Shanghai 200444, China)
Abstract: The effects of aluminum indium codoping on the microstructure and electrical properties of ZnO varistors, especially the surge impact stability, were studied. The microstructure was characterized by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrical properties were evaluated by using current-voltage test, pulsed current impulse test and capacitance-voltage test. The sample doped with 0.0008 mol% Al3+ and 0.0033 mol% In3+ exhibited excellent electrical properties, with breakdown voltage gradient of 95.3 V·mm−1, nonlinear coefficient of 74 and residual voltage ratio of 2.43. In addition, after 20 shocks at 8/20 μs 10 kA current, the positive and negative voltage change rates were +3.30% and −6.67%, respectively.
Key words: ZnO varistors; donor doping; electrical properties; surge impact stability