Polymer-nanotube composites for transparent, conducting thin films

Highly conductive, highly transparent thin films have been fabricated from polymer-single walled carbon nanotube blends. Using poly-3,4-ethylenedioxythiophene doped with poly(styrenesulfonate) as a host material, excellent dispersion of single wall nanotubes could be achieved enhancing the conductivity with relatively low loadings <3 wt%. Raman spectroscopy indicates that there is little bundling of the single wall nanotubes in the matrix and that the nanotubes are sensitive to residual stress within the film. As the host bulk conductivity is increased, enhancements of the overall composite conductivity are observed to be proportional. These results suggest that the energy barrier to nanotube-nanotube carrier hopping within the matrix can be modified in accordance with a heterogeneous conduction model. (C) 2005 Elsevier B.V. All rights reserved.