Correlating polymer solution conformation and thin film nanostructure: Implications for BHJ processing

We study the solution properties of polymer-fullerene mixtures by a combination of dynamic light scattering, viscometry, small angle neutron scattering and microscopy. Specifically, the kinetics of polymer conformation (Rg and Rh) and interaction changes are mapped as function of polymer-particle concentration, overall concentration in solution and age. A model system of polystyrene and C60 fullerene was selected for this study, in addition to the P3HT/PCBM pair, which is currently explored in photovoltaic applications. The solution properties show a clear correlation to the resulting thin film nanostructured composite morphology. Our future work will further link it to bulk heterojunction solar cell performance.