Comparison of ZnO-based varistor performance by doping Zn–Sb–O phase and Sb2O3 respectively

Abstract

In this study, ZnO–Bi2O3–Cr2O3–MnO2–B2O3 (ZBCMB) varistors were made by doping Zn–Sb–O phase and Sb2O3 phase in low-temperature respectively. Compared with the Sb2O3 doped sample, the breakdown field strength (E1mA) was effectively reduced from 605.36 V/mm to 440.24 V/mm due to the doping of Zn–Sb–O phase. The trend of the nonlinear coefficient α is similar for Sb2O3 and Zn–Sb–O doping, although Zn–Sb–O doping leads to a higher α = 64. This is due to the fact that the preparation of Zn–Sb–O phase avoids the oxygen vacancy reduction effect caused by the direct reaction of Sb2O3 with Bi2O3. The doping of Zn–Sb–O effectively increases the concentration of adsorbed oxygen, which has a very large positive effect on the formation of interfacial states and the increase of the potential barrier height.