Gate Controlled Negative Differential Resistance and Photoconductivity Enhancement in Carbon Nanotube Intra-connects

Field effect transistors were fabricated using carbon nanotubes (CNT). Gate-controlled, N-shaped negative differential resistance (NDR) has been demonstrated. In addition, a large photoconductance effect was associated with the NDR. The intra-connects -- bridges spanning across planar electrodes and contain individual tube or in a small bundle -- were grown using chemical vapor deposition (CVD) precisely between very sharp metal tips on the pre-fabricated electrodes. NDR was observed for intra-connects exhibiting either, ohmic or, non-ohmic contacts. Yet, the enhanced photoconductivity was more pronounced for intra-connects exhibiting ohmic contact at zero gate bias.