Terahertz conductivity of anisotropic single walled carbon nanotube films

Abstract

Absorption and dispersion of singlewalled carbon nanotube films were measured using an optoelectronic THz beam system for THz time-domain spectroscopy. The anisotropically aligned nanotube films were prepared through simple mechanical squeezing with a bar coater. The angle-dependent absorption and dispersion values were then measured. Results indicate that the index of refraction decreases with increasing frequency (0.1–0.8 THz), whereas the real conductivity increases with increasing frequency. The real conductivity measured is not congruent with the simple Drude model, but it follows a Maxwell–Garnett model, where the nanotubes are embedded in a dielectric host.