Electron transport through a conjugated molecule with carbon nanotube leads

A model carbon nanotube (CNT)-(CH)(n)-CNT structure is studied to understand electron transport through an interface between two conjugated systems. The conductance of the CNT-(CH)(n)-CNT structures strongly depends on the bonding angle of the (CH)(n)-CNT bond. The minimum-energy relaxed geometry is relatively coplanar. The relationship of the conductance on the length of the (CH)(n) depends on the geometry of the (CH)(n)-CNT interface. In the coplanar geometry, the conductance decreases with the length of the (CH)(n). In the perpendicular geometry, the conductance increases with the length of the (CH)(n). Calculations are performed using the nonequilibrium Green's function formalism and tight-binding density functional theory.