Photoinduced Self-Assembled Nanostructures and Permanent Polaron Formation in Regioregular Poly(3-hexylthiophene)

Abstract

Solution processing of conjugated polymers into ordered self-assembled precursors has attracted great interest in the past years owing to the ability to manipulate their structural and physical properties. Regioregular poly(3-hexylthiophene) (P3HT) has become the benchmark polymer in this scenario, where ordered lamellar structures significantly improve carrier mobility of the thin films due to increased crystallinity, extended intrachain conjugation, and ordered interchain π-stacking. Here, a new photoinduced approach is presented for the generation of highly ordered P3HT aggregate structures that is amenable to the use of visible light to control the aggregate formation. Strong intra- and interchain interactions in the solution precursors allow for permanent formation of localized and delocalized polarons that are stable for months. Spin-coated thin films are found to preserve, in part, the morphological and physical properties of the aggregated P3HT solution precursors with high degree of crystallinity and short π-stack interchain distances.

Highly crystalline poly(3-hexylthiophene) aggregates are generated in chloroform solutions by visible pulsed laser excitation, with permanent formation of localized and delocalized polarons due to strong intra- and interchain interactions. Spin-coated films preserve the morphological and physical properties of these self-assembled lamellar solution precursors, showing high crystallinity and short interchain distances. These results are relevant for developments in organic semiconducting applications.

http://ift.tt/2DcNIvY