Extended Data Fig. 2: CP solution aggregation behaviour upon addition of dopant.

a) In a perfect solvent, polymer chains are fully dissociated. b) In an intermediate solvent, polymer chains are both fully dissociated and forming small lamellar aggregates. c) Partial solvents give result to large polymer aggregates. Addition of dopant in a perfect solvent result in good CP-dopant intercalation owing to full dissociation of polymer aggregates, without a significant change in the aggregation behaviour. This is similar to adding a dopant in an intermediate solvent, where the CP has lower or affinity for the dopant than for the solvent (d). This should produce minimal effect on the resulting thin film morphology. In contrast, adding a dopant to an intermediate solvent (e) where the CP has similar or higher affinity for the dopant than for the solvent, a competing interaction is triggered that increases the polymer aggregates in solution. This case should result in an increase in the crystalline fraction and the EFR. Finally, in (f), adding dopants in a bad solvent should result in a decrease in the aggregates, due to the dopant attempting to intercalate with the CP. This should produce a film with hindered crystallinity and lower EFR.