Microstructure and electrical properties of vanadium-doped zinc oxide-based non-ohmic resistors

摘要

The microstructure and non-ohmic properties of the ternary system ZVM were investigated in accordance with Mn_3O_4 content. For all samples, the microstructure of the ternary system ZnO-V_2O_5-Mn_3O_4 consisted of mainly ZnO grain and secondary phase Zn_3(VO_4)_2. The incorporation of Mn_3O_4 to the binary system ZnO-V_2O_5 was found to restrict the abnormal grain growth of ZnO. The breakdown voltage in the V-I characteristics increased from 17.5 to 463.5 V/mm with the increase in Mn_3O_4 content. The incorporation of Mn_3O_4 up to 0.5 mol% improved non-ohmic properties by increasing non-ohmic coefficient, whereas the further additions decreased it. The highest non-ohmic coefficient (22.2) was obtained from Mn_3O_4 content of 0.5 mol%. It was found that the highest barrier height at grain boundary was 2.66 eV for Mn_3O_4 content of 0.5 mol%.