Jin-Feng Li

Surface-migration driving uniform amorphous shell on crystalline nanowire: the case of SiC/SiOx core–shell nanowires

Single-crystal SiC nanowires with controlled surface amorphous silicon oxide (SiOx) layers, including bare SiC nanowires, chain-like and cable-like SiC/SiOx nanowires, have been synthesized by a catalyst-assisted chemical vapor reaction approach, and the temperature-dependent morphology evolution of the surface amorphous layers is investigated in detail. Morphological, compositional and structural characterizations indicate that as-synthesized SiC nanowires consist of cubic phase single crystal cores with [111] growth direction and amorphous SiOx shell with varied morphology that can be tuned by temperature. The growth of the SiC nanowires is governed by the vapor–liquid–solid mechanism while the variation of surface SiOx amorphous layers is thought to be controlled by a surface migration process that is mainly dependent on temperature. The results would be helpful to achieve rational modulation of amorphous surface layers on semiconductor nanowires.