Terahertz conductivity of plasma-treated of CNT-based macroscale films

Time-domain terahertz and Fourier-transform infrared spectroscopy techniques are used to study temperature-dependent conductivity spectra of free-standing macroscale films composed of disordered single-walled carbon nanotubes. Films composed of nanotubes a) treated with oxygen plasma and b) having different lengths are used. We observed evolution of the so-called terahertz conductivity peak during the change of the temperature and the length of nanotubes. We analyzed changes of the terahertz conductivity of the films from metal-like to semiconductor-like due to oxygen plasma treatment and shortening length of the nanotubes.