Photoresponses of ZnO nanobridge devices fabricated using a single-step thermal evaporation method

Abstract

We have recently reported fabrication of ZnO nanobridge devices using a single-step thermal evaporation method. In this fabrication process, we completely eliminated the need of either any metal catalysts or a ZnO seed layer to synthesize the ZnO nanobridges. As initially postulated, the morphology of an anisotropic crystalline substrate alone defines the growth region to prevent the random growth of ZnO nanowires on the substrate. The photoresponses of a ZnO nanobridge device measured under the UV illumination ( λ = 365 nm) have indicated distinctively higher photosensitivity compared with a networked ZnO nanowire device fabricated by using a conventional photolithography technique. This result confirms that the single-step process not only provides a simple and a cost effective way to integrate self-assembled nanodevices comprised of individual and/or multiple ZnO nanobridges with conventional circuits without using e-beam lithography techniques and/or additional costly deposition processes but also allows one to fabricate devices with higher photosensitivity.