Unipolar resistive switching of solution synthesized ZnO nanorod with self-rectifying and Negative Differential Resistance effects

Abstract

In this article, we report the first observation of unipolar memory effect in Al/ZnO NR/Al planar devices. ZnO nanorods were synthesized using facile solution route at room temperature. The synthesized nanorods were characterized by X-ray diffraction and scanning electron microscope. Using the synthesized ZnO nanorods two terminal planar devices were fabricated with lithographically defined metal contacts. The constructed metal-ZnO-metal devices have exhibited unipolar resistive memory characteristics with rectification and NDR effects. Mechanism for the unipolar switching has been proposed based on the formation and rupture of AlOx interlayer in the metal-semiconductor interface. The simultaneous occurrence of rectification and NDR effects with switching property has also been explained. This article brings an innovative and easy fabrication of unipolar resistive switching devices. (C) 2014 Elsevier B.V. All rights reserved.