Preparation of High‐Quality ZnO Nanorods by Electrodeposition Using a Rotating Cathode and Improvements in their UV Sensing Properties

Abstract

In this study, we prepared ZnO nanorods on Si substrates by electrodeposition using a rotating cathode and investigated the effects of the rotating cathode on the properties of the electrodeposited ZnO nanorods and those of an ultraviolet (UV) detector based on ZnO nanorods. When the cathode was rotated at 250 rpm, the resulting ZnO nanorods exhibited improved vertical orientation, higher aspect ratio, and greater number density confirmed by scanning electron microscopy as well as improved directional growth along the (002) crystallographic plane. Furthermore, improved crystallinity was confirmed by X‐ray diffraction and photoluminescence analyses. A UV detector based on these ZnO nanorods electrodeposited using the rotating cathode at 250 rpm showed faster photoresponse growth, faster and higher photosensitivity compared to a detector based on ZnO nanorods electrodeposited using a non‐rotating cathode. This proposed method is suitable for growing dense and high‐quality ZnO nanorods and should allow for the fabrication of fast‐response UV detectors with high photosensitivities.