Semiconducting Oxide and Nitride Nanowires

Abstract

Binary semiconducting oxides, such as Ga2O3, In2O3, SnO2, and ZnO have distinctive properties and are now widely used as transparent conducting oxide materials and sensors [1]. For example, β-Ga2O3, with direct band gap energy Eg ≈ 4.9 eV, exhibits conduction and luminescence properties, and thus has potential applications in optoelectronic devices and high-temperature stable gas sensors. In2O3 (Eg = 3.55–3.75 eV) has been widely used in microelectronic field as window heaters, solar cells, and flat-panel display materials. SnO2, a very important n-type semiconductor with a wide band gap (Eg = 3.6 eV at 300 K), is well known for its potential applications in gas sensors, transparent conducting electrodes and transistors. ZnO (Eg ≈ 3.2 eV) is ideal for low-voltage and short wavelength (green or green/blue) electro-optical devices such as light emitting diodes and diode lasers [2]. On the other hand, one-dimensional silica nanostructures have attracted considerable attention because of their potential future applications in high-resolution optical heads of scanning near-field optical microscope or nanointerconnections in integrated optical devices [3]. Rationally controlled growth of nanowires consisting of the above-mentioned materials is important for their applications in nanoscale electronics and photonics. In this section we present the rational growth of these nanowires based on the results from our research group by using physical evaporation method. In addition, a novel synthetic method for semiconducting oxide nanowire arrays will be demonstrated by using electrochemical deposition of metal nanowires in the nanochannels of porous anodic aluminum oxide templates and subsequent oxidization in oxygen atmosphere.