Open AccessSynthesis mechanism of SiC–SiO2 core/shell nanowires grown by chemical vapor deposition
Author(s) -
Federica Finetti,
Enrico Cavalli,
G. Attolini,
Francesca Rossi
Publication year - 2020
Publication title -
nano express
Language(s) - English
Resource type - Journals
ISSN - 2632-959X
DOI - 10.1088/2632-959x/abb47a
Subject(s) - dewetting , nanowire , chemical vapor deposition , nucleation , materials science , vapor–liquid–solid method , raman spectroscopy , substrate (aquarium) , chemical engineering , nanotechnology , silicon , thin film , chemistry , optoelectronics , optics , physics , oceanography , organic chemistry , engineering , geology
Core–shell SiC–SiO 2 nanowires were grown on silicon substrate with the chemical vapor deposition method using iron nitrate as promoter for the growth and CO as a carbon precursor, under atmospheric pressure and at a temperature of 1100 °C. The whole process involves two main stages: promoter conditioning (dewetting) and growth, by reaction with CO. The dewetting phase has been characterized by SEM and TEM techniques, x-ray diffraction and Raman spectroscopy. The results show that at the operating temperature, a solid-state reaction between the substrate and the promoter takes place with the formation of α -FeSi 2 . The growth of the nanowires begins after an induction time of about 5 min from the introduction of CO. The experimental data have been interpreted by considering a nucleation process involving a reaction between FeSi 2 and CO. For the nanowires growth phase, a mechanism based on the Vapor-Liquid-Solid theory is proposed, compatible with the morphology of the drop-shaped particles present on the tip of the nanowires.