Exciton dynamics in disordered poly(p-phenylenevinylene). 2. Exciton diffusion.

We present a first principles theory of exciton diffusion in conformationally disordered conjugated polymers. Central to our theory is that exciton transfer occurs from vibrationally relaxed states (VRSs) to local exciton ground states (LEGSs). LEGSs are determined by the diagonal and off-diagonal disorder induced by static density and torsional fluctuations, and VRSs are further localized by exciton-phonon coupling.