Interplay of processing, morphological order, and charge-carrier mobility in polythiophene thin films deposited by different methods: comparison of spin-cast, drop-cast, and inkjet-printed films.

The dependence of morphology and polymer-chain orientation of regioregular poly(3-hexylthiophene) (rrP3HT) thin films on processing conditions have been widely studied. However, their possible variation across the film thickness direction remains largely unknown. We report here a marked difference in the optical dielectric (n,k) spectra between the top and bottom interfaces of spin-cast (sc) rrP3HT films deposited from chlorobenzene solutions.