Structuration of semiconducting polymer thin films by nanorubbing.

In this paper, we study the behavior of thin films of a semiconducting polymer, poly(3-hexylthiophene)-P3HT under the application of a physical constraint. We have rubbed P3HT thin films with a velvet cloth, which leads to the alignment of the polymer chains along the sliding direction at the film surface. Annealing the rubbed films up to the crystallization temperature, leads to the propagation of the surface orientation to the whole film. In order to gain spatial and geometrical control on the rubbing process, we have used nano-rubbing. Using the stylus of an AFM working in contact mode, the nano-rubbing process can be performed locally on an area of defined size. These chain-aligned structures can be permanent thanks to the crystallization process. This study opens interesting opportunities to control the molecular order within the channel of field-effect transistors.