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

• Two terminal planar devices fabricated using solution synthesized ZnO nanorods.
• Al/ZnO NR/Al devices successfully fabricated using lithographically patterned metal electrodes.
• The I-V characterization of the device has shown unipolar resistive switching property with self rectification and NDR effects.
• This the first report on the observation of unipolar switching property in solution synthesized ZnO nanorods.

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.