Carrier transport and light-spot movement in carbon-nanotube infrared emitters

Infrared emission from a carbon-nanotube (CNT) field-effect transistor, with the position of the light spot controlled by applied bias, was recently reported. In this letter, a self-consistent simulation, which couples a quantum treatment of the metal-CNT contacts to a semiclassical treatment of the channel, is performed to understand carrier transport and light emission in a CNT infrared emitter. The results show that when the channel is long, light emission significantly affects carrier transport, and reduces the source-drain current by a factor of 2 in ambipolar transport regime. The experimentally observed light-spot movement along the channel can be mostly understood and explained by a simple, semiclassical picture. (C) 2005 American Institute of Physics.