Study of electrical conductivity of the poly(3 hexylthiophene-2, 5-diyl) polymer in resonant Fabry–Perot cavities

Enhancing electrical conductance in organic semiconductors has been a focus of intense research over the last few decades. The improvement can be made by optimizing either the material or the device architecture. As it has been shown by Orgiu et al., strong coupling of organic molecules with a nanostructured plasmonic substrate can significantly improve the molecules’ electrical conductivity. We searched for the effect of strong coupling with a Fabry–Perot cavity on the conductivity of the semiconducting poly(3 hexylthiophene-2, 5-diyl) (P3HT) polymer. Despite the observation of the strong coupling evidenced by a very large Rabi splitting of 1.0 eV, the increase of electrical conductivity with increase of the P3HT film thickness was primarily affected by an increase of the polymer’s order in thick P3HT films.