Morphological tuning and conductivity of organic conductor nanowires.

We report the synthesis of small-molecule organic conductor nanowires of TTF-TCNQ by selective inducement in a two-phase method by pi-pi stacking interaction. The morphologies of TTF-TCNQ, from straight nanowires to helical nanowires and to complicated helical dendrite structures, have been controlled by adjusting the experimental conditions. The technique has been applied to the synthesis of AgTCNQ/CuTCNQ nanowires in a two-phase system of acetonitrile/hexane. I-V characterization of an individual nanowire indicated that the conductivity along the b-axis of the TTF-TCNQ helical nanowire is much better than that along other directions. The synthetic procedure presented is a general approach for producing controlled organic conductor/semiconductor nanowires.