Modeling of the resistance between metal electrodes and metallic SWNT

Contact effects of carbon nanotubes (CNT) to metallic electrodes have a big impact on the electronic transport in CNT-based structures. In general there are two expected types of contacts, Schottky type with semiconducting tubes and ohmic contact with semiconducting and metallic tubes. However not always perfect contacts come, it is rather a tunneling barrier contact because of the weak coupling to the metal electrode or the formation of thin layer of oxides at the interface, for example. We propose a simple model for non-ideal contacts of metallic single walled nanotube (SWNT) in order to calculate the overall resistance and hence the contact resistance. The model takes into account the findings of both experiments and theories such as effect of work function, electron phonon scattering in low and high bias voltage, image potential and van der Waals distance at the interface. The model can be developed to calculate the contact resistance for strips of several SWNTs or multiwalled carbon nanotubes MWNTs.