Facile Method for the Investigation of Temperature-Dependent C Diffusion in Conjugated Polymers.

We developed a novel all-optical method for monitoring the diffusion of a small quencher molecule through a polymer layer in a bilayer architecture. Experimentally, we injected C molecules from a C layer into the adjacent donor layer by stepwise heating, and we measured how the photoluminescence (PL) of the donor layer becomes gradually quenched by the incoming C molecules. By analyzing the temporal evolution of the PL, the diffusion coefficient of C can be extracted, as well as its activation energy and an approximate concentration profile in the film.