Condensed Matter Seminars

Due to the low dimensionality of carbon nanotubes (CNTs), charging of a single defect site near a CNT may have a profound effect on modifying carrier transport mobility in a long CNT channel. Random Telegraph Signals (RTS) have been studied in carbon nanotube field effect transistors (CNT-FETs). If the energy of the defect center is close to the Fermi level of the CNT-FET, trapping and detrapping of carriers would modify the carrier transport in the channel, and give rise to RTS. RTS is observed as a switching between discrete current levels, representing a carrier being trapped and detrapped successively in the defect center. We speculate that RTS spectra could provide a characteristic signature of specific adsorbates or adducts on the nanotube channel. This capability is of interest not only for potential sensing technology but also provides a way to introduce controllable quantum interference resonances in the channel transport.