Asymmetric carrier accumulation in double-walled carbon nanotube by an external electric field

We studied the electronic structure of a double-walled carbon nanotube (DWCNT) in a field-effect transistor structure under an external electric field. Our calculations using density functional theory combined with the effective screening medium method showed that the carrier accumulation in the DWCNT is sensitive to the carrier species and concentration. Injected holes are distributed primarily on the outer wall of the DWCNT, whereas the electrons are accommodated on both its outer and inner walls. The extended nature of the accumulated electron density leads to an interwall electric field from the outer to the inner wall. (C) 2017 The Japan Society of Applied Physics