Field–effect Transistor Structures with Quasi–one–dimensional Channel

Drift–diffusion model is applied for transport in a one–dimensional field effect transistor. A unified description is given for a semiconductor nanowire and a long single–wall nanotube basing on a self–consistent electrostatic calculations. General analytic expressions are found for basic device characteristic which differ from those for bulk transistors. We explain the difference in terms of weaker screening and specific charge density distribution in quasi–one–dimensional channel. The device characteristics are shown to be sensitive to the geometry of leads and are analyzed separately for bulk, planar and wire contacts.