Influence of Small Amounts of Dispersed Single-Walled Carbon-Nanotubes on the Optical Properties of Poly-3-hexylthiophene

We studied the dispersion of single-walled carbon-nanotubes (SWNTs) in poly-3-hexylthiophene (P3HT) and the influence of their dispersion on the optical properties of the polymer. The bundles of SWNTs were found to be well dispersed in P3HT solution, being broken up into finer ropes. We also found that dispersal of only a small amount (less than 1 wt%) of SWNTs in P3HT gives rise to a steep increase in optical absorbance close to the absorption edge, remarkable quenching of photoluminescence, and formation of oriented micro-domains. These results suggest that an ordered structure in the conjugation of P3HT is formed by the incorporation of SWNTs.