Simultaneous measurement of photoluminescence and Raman scattering spectra from suspended single-walled carbon nanotubes

摘要

Single-walled carbon nanotubes (SWNTs) are interesting material, owing to their one-dimensional structure. Photoluminescence (PL) spectroscopy and resonant Raman scattering spectroscopy are important measurement techniques to characterize SWNTs. The simultaneous measurements of PL and Raman scattering spectra have been performed for SWNT samples, which were wrapped with surfactant and dispersed on substrates. Here, we developed the simultaneous measurement technique of PL and Raman scattering from a perfectly isolated SWNT. The isolated SWNT was suspended between a pair of silica pillars, and it was free from any substances. The laser beam generated from a Ti: sapphire laser was focused with objective lens to spot size of 1.6 μm in diameter for the excitation of a suspended SWNT. Raman scattering and PL emission light from an SWNT were separated with a dichroic mirrors and introduced into each monochromator. By using the simultaneous measurement, the intensity profiles along a suspended SWNT were compared between PL and Raman scattering, which showed rapid quenching of PL signals at the pillars.