Progress on rare-earth doped ZnO-based varistor materials

Abstract

Rare-earth (RE) doping can greatly enhance the voltage gradient of ZnO-based varistors, and their nonlinear coefficient, leakage current, energy absorption capability, through-current capability and residual voltage can also be improved to certain extent. In this review, the progress on RE-doped ZnO-based varistor materials in recent years was summarized. The mechanism of RE doping on the electrical performance of ZnO varistors was analyzed. The issues in exploring new ZnO-based varistor materials by RE doping were indicated, and the development trends in this area were proposed.

Microstructure and Nonohmic Properties of SnO2-Ta2O5-ZnO System Doped with ZrO2

“…The leakage current of the samples presented an opposite trend to that of nonlinear coefficient with ZrO 2 doping, and the varistors with 1 mol% ZrO 2 presented the lowest leakage current, 110  μ A/cm 2 , which is completely consistent with classic theory on their relationship [18]. Thus, it can be concluded that the optimum doping amount of ZrO 2 in the proposed SnO 2 -Ta 2 O 5 -ZnO-based ceramic varistor system was 1 mol%.…”

High-performance varistors simply by hot-dipping zinc oxide thin films in Pr6O11: Influence of temperature

“…With the increase of hot-dipping temperature, the leakage current of the samples shows a trend against the nonlinear coefficient. The high nonlinear coefficient for a varistor would lead to low leakage current because of the formation of a relatively high tunnel current, while the low nonlinear coefficient would result in high leakage current due to the formation of higher thermal excitation radio current25.…”

Identifying the influence of the intrinsic defects in Gd-doped ZnO thin-films

“…1,2 Doping ZnO with rare earth (RE 3þ ) ions enables further electrical, optical, and magnetic applications due to the unique character of partially filled 4f shells. [3][4][5][6] For example, Yang et al 4 reported a light-emitting diode prototype based on RE-doped ZnO, capable of emitting across all wavelengths in the entire visible region. In addition, Gddoped/implanted ZnO exhibited room temperature (RT) ferromagnetic behavior that has been attributed to defect/impurity bands mediated by Gd dopants.…”