Optoelectronics of Single Carbon Nanotubes

CNTs are one-dimensional materials with unique properties that make them ideal for applications in nanoelectronics and optoelectronics. Particularly strong emphasis has been placed on carbon nanotube field-effect transistors (CNTFETs). In these devices a semiconducting, single-walled, nanotube molecule replaces silicon as the transistor "channel." CNTFETs with thick gate dielectrics tend to be unipolar p-type devices. Upon scaling of the oxide thickness, however, the Schottky barriers present at both source and drain are screened by the gate and become sufficiently thin to allow the simultaneous injection of electrons and holes from opposite ends of the CNT channel, i.e. the transistor becomes ambipolar (a-CNTFET).