Characteristics of nano-scale composites by THz spectroscopy

We have conducted visible pump-THz probe experiments on single wall carbon nanotubes (SWCNTs) on quartz substrates. Our results suggest an upper limit to the carrier-lifetime, which is on the order 1.5ps, limited only by the THz pulse duration. These experiments were repeated for ion-implanted, 3-4nm Si nanoclusters in quartz for which the carrier lifetime was also assessed at 1.5ps. THz time-domain spectroscopy (THz-TDS) of SWCNTs revealed that the THz pulse peak transmission changed under optical illumination.