Electrical and Optical Properties of Conducting Poly(3-hexylthiophene)/Multi-walled Carbon Nanotube System

Polymer multi-wall carbon nanotube (MWNT) composites were prepared and characterized as part of an effort to develop polymeric materials with improved combinations of properties for potential use in solar cell applications. Multi-walled carbon nanotube (MWNT) poly(3-hexylthiophene) nanocomposites were synthesized by in situ polymerization of monomers in the presence of different amounts of MWNTs. A process is reported to efficiently disperse multi-walled carbon nanotube (MWNT) bundles in a semiconducting polymer matrix. A uniform dispersion of the nanotubes in the polymer matrix was obtained. Characterization of the nanocomposites and the effects of MWNT concentration and dispersion on the structural, optical and electrical properties were discussed. FTIR and Raman spectroscopic investigations of nanocomposites indicate that the polymer is wrapped on the nanotubes, taking up a rigid orientation through π-π stacking. The Hall voltage measurement is followed to monitor carrier concentrations and mobilities, instead of the device fabrication and hole mobility measurements.