title: Silicon carbide embedded in carbon nanofibres: structure and band gap determination.
abstract: Materials drastically alter their electronic properties when being reduced to the nanoscale due to quantum effects. Concerning semiconductors, the band gap is expected to broaden as a result of the quantum confinement. In this study we report on the successful synthesis of wide bandgap SiC nanowires (with great potential for applications) and the local determination of their band gap. Their value was found to be higher with respect to bulk SiC. The nanowires are grown as a heterostructure, i.e. encapsulated in carbon nanofibres via dc hot-filament Plasma-Enhanced Chemical Vapour Deposition on the Si/SiO2 substrate. The structure of the as-produced carbon nanofibres was characterized by means of aberration-corrected high-resolution transmission electron microscopy. Two different pure SiC polytypes, namely the 3C (cubic) and the 6H (hexagonal) as well as distorted structures are observed. The SiC nanowires have diameters in the range of 10-15 nm and lengths of several hundred nanometers. The formation of the SiC is a result of the substrate etching during the growth of the CNFs and a subsequent simultaneous diffusion of not only carbon, but also silicon through the catalyst particle.
authors.affiliation: Institute for Metallic Materials, IFW Dresden, P.O. Box 270116, D-01171 Dresden, Germany. b.rellinghaus@ifw-dresden.de.
authors.forename: Anja Bonatto
authors.initials: AB
authors.lastname: Minella
authors.forename: Darius
authors.initials: D
authors.lastname: Pohl
authors.forename: Christine
authors.initials: C
authors.lastname: Täschner
authors.forename: Rolf
authors.initials: R
authors.lastname: Erni
authors.forename: Raghu
authors.initials: R
authors.lastname: Ummethala
authors.forename: Mark H
authors.initials: MH
authors.lastname: Rümmeli
authors.forename: Ludwig
authors.initials: L
authors.lastname: Schultz
authors.forename: Bernd
authors.initials: B
authors.lastname: Rellinghaus