Electrical Properties of ZnO/PrCoOxide Multilayered Composites

Multilayered composites having the structure of Ni/ZnO/PrCoOxide/Au were fabricated by the sputtering technique and their electrical properties were examined. It was found that a multilayered composite is an excellent low voltage varistor (α=30, breakdown voltage=6.5V). The results of the voltage-current (V-I) and the capacitance-voltage (C-V) measurements revealed that a depletion region was formed in the ZnO thin film close to the ZnO/PrCoOxide interface. The potential barrier in the ZnO/PrCoOxide multilayered composite was discussed in comparison with a single grain boundary model in ZnO ceramic varistors.