AbstractIn the present article we will discuss the electronic trans‐ port properties of carbon nanotube field‐effect transistors (CNFETs). Three different device concepts will be studied in more detail: Schottky‐barrier CNFETs with metallic source and drain contacts, conventional‐type CNFETs with doped nanotube segments as source and drain electrodes and finally a new concept, the tunneling CNFET. As it turns out, tunneling phenomena play a prominent role in all three CNFET designs and determine their electrical behavior to a large extend. In addition, the one‐dimensionality of the electronic transport makes them ideally suited for novel device architecture such as the tunneling CNFET. Analytical as well as simulation results will be given and compared with each other and with experimental data in order to explain the different influences on the electronic transport in CNFETs and thus on the device behavior. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)