Abstract Submitted to the    NANOTUBE'04 Conference:

Among the properties of Carbon Nanotubes (CNTs), the observation of luminescence in the near infrared (near IR) region from semiconducting single walled carbon nanotubes (SWNTs) along with the finding that field effect transistors (FETs) based on SWNTs can work as IR-electro-luminescent devices open new perspectives in the optoelectronic sector, determining a great interest in the optical properties of SWNTs. Nevertheless, in order to further prompt the devolpment of such new devices, a comparison with the properties of silicon, the leading material in the microelectronic industry, is of help. For this reason we have undertaken an experimental investigation of the optical properties of purified SWNTs deposited, in particular, on a (100) Si p- surface. The optical properties of SWNTs have been observed in the ultraviolet (UV)-visible and near IR regions and have been gained by measuring the absorption determined by SWNTs deposited on Si both by recurring to the transmitting mode and reflectance mode. In particular, we demonstrate as it is possible to gain information on the optical properties of SWNTs in the near IR region by determining their absorption that can be ascribed to the energy gap of semiconducting carbon nanotubes from reflectance measurements.