Electromechanical coupling in coaxial semiconductor carbon nanotube intramolecular junctions

Institute of High Performance Computing - 1 Fusionopolis Way, 16-16 Connexis, Singapore 138632, Singapore

^a wugaxp@gmail.com
^b wuping@ihpc.a-star.edu.sg

Received: 4 April 2011
Accepted: 16 June 2011

Abstract

The structure, electronic and transport properties of coaxial semiconductor-semiconductor carbon nanotube intramolecular junctions (IMJs) with uniaxial strain have been studied by the tight-binding (TB) model and nonequilibrium Green's function approach. Inhomogeneous deformation is found in the strained IMJs, which leads to regular evolution of conductance gap. We present a simple model to establish the relation between the effective local strains of tubular segments and global strain of the whole IMJ. Furthermore, the lower and upper limits of the conductance gap of IMJ are obtained by taking the maximum value of the band gaps of tubular regions, which can be analytically evaluated using π-orbital TB model. The obtained limits are qualitatively consistent with numerical π-orbital and four-orbital TB simulations. Our work enriches the understanding of electronic and transport properties of IMJ, and can be employed as an aid tool to experimental studies of nanotube electronic devices.