Infrared absorption properties of carbon nanotubes synthesized by chemical vapor deposition

Abstract

We present an infrared (IR) optical absorbance study of highly uniform nanotubes grown by chemical vapor deposition in the self-assembled porous matrix in alumina. For unambiguous IR spectral measurement, nanotubes were extracted from their growth template, purified, and evenly dispersed on a reflecting substrate. The findings, which are consistent with previous results from conduction studies, reveal that the nanotubes are semiconducting with a band gap of $\sim 100\mathrm{meV}$ . This suggests the potential of nanotube arrays for IR electro-optical device applications.