Synthesis and characterization of arrays of metal oxide nanowires with highly controllable diameters for future sensor applications

Abstract

Tin oxide (SnO2) is a semiconducting material with a high transparency, a low resistivity and a high biocompatibility. With these properties SnO2-based sensors could be used in many fields, ranging from the detection of gasses to the detection of light. To increase the sensitivity of such a sensor the surface-to-volume ratio has to be increased. This can be achieved by patterning on the nanometer scale or, in other words, by synthesizing 1D nanostructures in a very high density at the surface of an appropriate substrate. When the nanowires become small enough in diameter (<10 nm) quantum size effects start to play an increasingly important role thus influencing all properties of the nanowires. When creating nanowires with the Vapour Liquid Solid (VLS) method the diameter of the wires usually depends on the diameter of the catalyst particle used to synthesize the wires. However, diameters below 20nm are difficult to achieve via VLS even with catalyst sizes well below 10 nm. Creating ver