Cubic Silicon Carbide Nanowires

Nowadays semiconductor nanowires (NWs) represent not only a field of great interest for the study of nanoscale new phenomena, but the technology has become increasingly mature insomuch as they are expected to give a fundamental contribution to electronic devices. Silicon carbide nanowires (SiC-NWs) embody a unique confluence of the well-known SiC chemical and mechanical peculiar properties with the size-dependent characteristics of quasi-one-dimensional structures. However, the synthesis of SiC nanostructures with tailored structure and their use in functional devices is still a challenge. In this chapter firstly a brief review on recent progress and the growth techniques used in literature to obtain SiC nanowires are introduced, then a survey of the growth mechanism of nanowires from vapour phase is presented. Some methods used to deposit catalysts for the growth are reviewed and the so called "dewetting" mechanism is analysed and studied with selected examples after a brief treatise of the thermodynamic of the phenomenon. The procedures for the synthesis of pure cubic silicon carbide nanowires by vapour phase epitaxy and core-shell SiC/SiO2 nanowires by chemical vapour deposition are presented and the morphology and structure are investigated by means of electronic microscopy. Finally, for core-shell nanowires, X-ray photoelectron spectroscopy is presented as a powerful technique to analyse the chemical and electronic state of the core and cathodoluminescence measurements show the influence of the shell on the optical emission of the SiC core embedded in the wires.