Gold deposition effects on photoluminescence and Raman scattering spectra of suspended single-walled carbon nanotubes

Abstract

Gold (Au) deposition effects on suspended single-walled carbon nanotubes (SWCNTs) were investigated by photoluminescence (PL) and Raman scattering spectroscopies. Deposited Au atoms formed particles on the SWCNT surface. The PL intensity decreased with increasing Au coverage, while the enhancement of the G-band in Raman scattering spectra was observed owing to the surface-enhancement Raman scattering (SERS) effect. The changes in the optical transition energy obtained from the PL spectra and Raman shift of the G-band revealed that tensile strain, which reached 5 × 10−3, occurred along the tube axis and was proportional to the Au coverage. The Au coverage dependence of the uniaxial strain can be understood in terms of the difference in the thermal expansion between SWCNT and Au.