Local Synthesis of Single-walled Carbon Nanotubes on Zeolite-covered Silicon Substrate by Laser-heating Chemical Vapor Depositon

Abstract

Single-walled carbon nanotubes (SWNTs) have been locally synthesized on zeolite-covered silicon substrates by laser-heating chemical vapor deposition (CVD). We used laser irradiation as a heat source, Fe/Co nanoparticles supported on zeolite as catalysts, and ethanol vapor as a carbon source. We heated the zeolite catalysts using a Nd:YAG laser at 50 mW with a spot size of about 5mum diameter and synthesized SWNTs in a local area of about 20mum diameter at the irradiation point. We also synthesized SWNTs in a line by scanning the laser irradiation at 800mW at an average speed of 10mum/s. The synthesized SWNTs were characterized by scanning electron microscopy and Raman spectroscopy. To investigate the effect of heating SWNTs by the laser, we irradiated pure SWNTs synthesized by standard CVD in a vacuum furnace using the laser. Furthermore, we succeeded in bridging zeolite islands using SWNTs by laser-irradiating one side of the islands.