Highly Uniaxial Orientation in Oligo(p-phenylenevinylene) Films Induced During Wet-Coating Process

Highly uniaxial alignment of π-conjugated oligo(p-phenylenevinylene)s was spontaneously achieved in the as-cast films by simply spin-coating the solution onto mechanically rubbed polymer alignment layers such as poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonic acid) (PEDOT:PSS) film, resulting in a high dichroic ratio (A///A⊥) of 41.0 and an order parameter ([A// − A⊥]/[A// + 2A⊥]) of 0.93 estimated from the polarized absorption spectra of the films, and its application to organic photovoltaic devices was also demonstrated to achieve a high anisotropy in photosensitivity.