Charge-transport behavior in shape-controlled poly(3,4-ethylenedioxythiophene) nanomaterials: intrinsic and extrinsic factors.

The charge-transport behavior in one-dimensional (1D) poly (3,4-ethylenedioxythiophene) (PEDOT) nanomaterials of three different shapes is described. Both intrinsic and extrinsic factors are considered from the viewpoint of a single nanoparticle and nanoparticle assembly. Intrinsically, the oxidation level of the 1D PEDOT nanomaterials becomes higher with increasing aspect ratio of the nanomaterials, which is closely linked to the conjugation length. This result implies that the transport properties of the nanomaterials are significantly dependent on their shape. Extrinsically, the 1D PEDOT nanomaterials make an ohmic contact with gold interdigitated microelectrodes. In addition, a strong correlation is observed between the interparticle contact resistance and the shape of the nanomaterials. Lastly, the intrinsic and extrinsic factors related to charge transport are further illustrated by the resistance changes of nanomaterial-based chemical sensors. As a result, judicious tailoring of the dimensional and geometrical characteristics of the conducting-polymer nanomaterials may enable precise control over their transport properties as well as the characteristics of the nanomaterial-based devices.