TEMPERATURE EFFECTS IN RAMAN SPECTRA FROM SINGLE-WALLED CARBON NANOTUBES AND ASSIGNMENTS OF THEIR CHIRAL INDICES AT HIGH TEMPERATURE

摘要

The temperature dependence of radial breathing mode (RBM) signals in resonance Raman spectra from single-walled carbon nanotubes (SWCNTs) on a SiO_2/Si (001) substrate is studied in the temperature range between 25 and 720 °C. The frequencies of RBM peaks tend to simply decrease with increasing temperature. In addition, a change in the relative intensity of each RBM peak with temperature is observed, which originates from the temperature dependence of the resonance condition of nanotubes. By taking into account the temperature-dependent behavior of the RBM peaks, each RBM peak is successfully assigned between 25 and 720 °C. It is found that most of the observed RBM peaks for a laser excitation energy of E_(exc) - 1.96 eV are from chiral SWCNTs. These results make it possible to analyze further details of the chirality-dependent growth behavior observed in in-situ Raman spectroscopy.