Microscopic Analysis of Graphene and Carbon Nanotube Growth

Abstract

We have observed chemical vapor deposition (CVD) processes of single-walled carbon nanotubes (SWCNTs) using scanning electron microscopy (SEM) by repeating ethanol exposure and observation without ethanol at an elevated temperature. The initial stage of SWCNT growth and their extension process were analyzed on the SiO2/Si substrate. On the patterned substrate, suspended SWCNT formation processes were successfully traced. Both the observations of growth on the substrate and that between mesa patterns suggest fluctuation of SWCNT growth direction during CVD cause SWCNTs falling on the substrate, forming nearest neighbor suspension and bundling. For graphene segregation on the nickel surface, the formation process could be observed by SEM, enabling preparation of layer-number defined graphene specimens useful for the researches of secondary electron image formation.