Varistor performance of nanocrystalline Zn-Bi-O thin films prepared by reactive RF magnetron sputtering at room temperature

Abstract

The Zn–Bi–O films were deposited by reactive radio frequency magnetron sputtering in oxygen atmosphere from ZnBi alloy target (wt. ratio Zn:Bi=9:1) on glass substrate at room temperature. The XRD patterns show that the films deposited on tin-doped indium oxide/glass substrates were nanocrystalline. The microstructure of Bi-doped ZnO films was studied by scanning electron microscopy in combination with energy dispersive X-ray spectroscopy. All the obtained layers had varistor-type non-linear current–voltage (I–V) characteristics with low breakdown voltage varying from few tenths of a volt to few volts