摘要
The dynamics of the chemical vapor deposition(CVD)of single-walled carbon nanotubes(SWNTs)is extracted experimentally using in situ Raman spectroscopy.Nanotubes are grown using a thinlm cobalt catalyst and an ethanol precursor in a miniature hot walled reactor with optical access.Raman spectra at room temperature and at the growth temperature are compared for two growth temperatures.The evolution of the G-band,D-band,and radial breathing mode(RBM)is tracked at the growth temperature with time resolution of a few seconds.There are three identifiable phases in the evolution of the Raman signal intensity:an initial exponential increasing phase,a linear growth phase,and a saturation phase.In situ optical spectroscopy thus enables the study of nucleation,steady growth,and deactivation processes to be investigated separately in real time.The evolution curves for all bands(G,D,and RBM),when scaled,collapse onto the same curve,to within experimental uncertainty.
基金
A discovery grant(PF,AL)from Natural Sciences and Engineering Research Council of Canada(NSERC)and a grant(AL)from Le Fonds québécois de la recherche sur la nature et les technologies(FQRNT)are gratefully acknowledged.We are grateful for the ongoing assistance of P.Marshall,Hue Tran,Jeff Fraser and other IMS staff and for preliminary research in this area by Jeffery Bond and Kate Kaminska.We are grateful for the funding of in situ Raman studies via the former JST-CREST"Nanofactory"project led by Yoshikazu Homma
