Observation of a Type II Heterojunction in a Highly Ordered Polymer-Carbon Nanotube Nanohybrid Structure

We report a study of the electronic properties of the heterojunction between regioregular poly(3-hexylthiophene) (rrP3HT) and single-walled carbon nanotubes (SWNTs). Comparison of the spectroscopic data of nanotube dispersions in a range of polymers indicates significant changes in the nature of the observed SWNT excitons only in combination with rrP3HT. A detailed analysis concludes that a type II heterojunction between rrP3HT and small diameter s-SWNTs is formed, making these particular nanohybrids a promising material for organic photovoltaics.