Raman Spectroscopy of Carbon Nanotubes under Axial Strain: Raman Spectroscopy of Carbon Nanotubes under Axial Strain and Surface-Enhanced Raman Spectroscopy of Individual Carbon Nanotubes
April 11, 2010 by AboutNanoWires.com · Leave a Comment
Product Description
Resonant Raman spectroscopy of individual carbon nanotube bundles under axial strains up to 17% are presented. This strain causes nanotube debundling which gives insight into the nature of the broad metallic G- band. For metallic nanotubes, the G- band upshifts and narrows with strain, making it appear more semiconductor-like. This metal to semiconductor transition is irreversible with strain, indicating that nanotube-nanotube coupling plays a significant role in the observed G- band of metallic nanotubes. The vibrational and electronic properties of these nanotubes under strain are modeled using tight-binding calculations. A systematic study of surface enhanced Raman spectroscopy (SERS) of carbon nanotubes. Raman spectra of individual carbon nanotubes are measured before and after depositing silver nanoparticles. Regions exhibiting SERS enhancement were located relative to a grid, allowing subsequent scanning electron microscopy to be performed. SERS enhancement factors up to 134,000, a consistent upshift in the G band Raman frequency and nanoparticle heating in excess of 600°C are revealed.



