Single Titanium Oxide Nanodot Ultraviolet Light Sensor Created by Atomic Force Microscopy Nanolithography

摘要

Recently, semiconductor oxide nanomaterials have drawn much research attention because of their extraordinary physical and chemical properties. Applications in a wide range of research areas have been reported, especially in the field of sensing. In this article, we report on the fabrication of a single titanium oxide nanodot (ND) nanosensor by atomic force microscopy nanolithography. A single titanium nanowire and gold contact electrodes are first created. A titanium oxide ND is then generated, which becomes a metal-oxide-metal structure, and can be used for detecting ultraviolet (UV) light. The detection mechanism is based on the desorption of oxygen molecules on the ND surface upon UV irradiation, which in turn increases the conductance. Two types of nanosensors, namely ohmic and Schottky, have been obtained by selecting oxidation regions in the nanowire and at the gold-titanium interface. The latter has a much higher sensitivity than that of the former. In addition to UV light sensing, the ND sensor can also be used for gas or chemical sensing and becomes a multi-functional nanosensor.