Nanoswitch based on telescoping double-walled carbon nanotubes and ‎the effect of vacancy defect on its electrical performance

Authors

Abstract

In this paper, we have simulated and investigated the conductance and electron transport of telescoping ‎double-walled carbon nanotubes (TDWCNTs) with and without vacancy defect, using tight-binding model ‎combined with nonequilibrium Green’s function (NEGF) approach. The simulation results show that the relative ‎motion of the walls along the tube axis causes periodic valleys and peaks in electrical conductance. Each of ‎these valleys and peaks can be considered as low (OFF) and high (ON) conductance respectively. As a result, ‎TDWCNT device can be used as a nanoswitch in nanoelectromechanical systems (NEMS). In addition, our ‎results show that introduction of a vacancy defect decreases the conductance by 50%. Reduction of the ‎conductance depends on the location and density of the defect. If the density of the defect is low in the ‎structure, the conductance of the device is not much affected. Therefore, the defective device can be still used ‎as a nanoswitch because of nearly constant ON/OFF conductance ratio. If the density of the defect is high, the ‎conductance is significantly affected and the performance of the device as a nanoswitch is degraded.‎

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