AVS 53rd International Symposium
    Nanometer-scale Science and Technology Wednesday Sessions
       Session NS-WeA

Paper NS-WeA5
Size Effects on Electrical Contacts to Nanotubes and Nanowires

Wednesday, November 15, 2006, 3:20 pm, Room 2020

Session: Nanotube Devices and Processes
Presenter: F. Leonard, Sandia National Laboratories
Authors: F. Leonard, Sandia National Laboratories
A.A. Talin, Sandia National Laboratories
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Metal-semiconductor contacts play a key role in electronics. Here we show that for quasi-one-dimensional structures such as nanotubes and nanowires, side contact with the metal only leads to weak band re-alignement, in contrast to bulk metal-semiconductor contacts. Schottky barriers are much reduced compared with the bulk limit, and should facilitate the formation of good contacts. However, the conventional strategy of heavily doping the semiconductor to obtain ohmic contacts breaks down as the nanowire diameter is reduced. The issue of Fermi level pinning is also discussed, and it is demonstrated that the unique density of states of quasi-one-dimensional structures makes them less sensitive to this effect. Our results agree with recent experimental work, and should apply to a broad range of quasi-one-dimensional materials.