Influence of heating and laser irradiation on the Raman D band in single-wall carbon nanotubes

Fine structure of the Raman D band in single-wall carbon nanotubes (SWNTs) was investigated by heating and laser irradiation. It is shown that the D band is composed of three components at similar to 1313, 1340, and 1355 cm(-1), denoted by D-1, D-2, and D-3, respectively. The D-1 and D-2 intensities significantly increase with laser irradiation in air and vacuum, respectively. The D-3 intensity drastically increases with heating in air. From these results, it is suggested that the fine structure of the D band is attributed to different kinds of defects introduced in SWNTs. (C) 2009 Elsevier B.V. All rights reserved.