Computational study of PEDOT derivatives: reducing air stability to satisfy the self-doping criteria of transparent conjugated polymers

PEDOT has been one of the most extensively studied conjugated polymers due to its unique combination of good transparency and high electrical conductivity, making it a promising alternative to ITO electrodes. With the aim of designing more conducting and transparent chains, we provide here a state-of-the-art quantum-chemical (TD)-DFT analysis to investigate whether significant HOMO level destabilization and red-shifted optical absorption in the doped state can be achieved through simple derivatization schemes. We demonstrate that a copolymer featuring an alternation of an EDOT unit and a substituted thiophene ring can compete with PEDOT. Moreover, the calculations indicate that the exact layout of the substituents on the thiophene rings can tune the extent of delocalization of the charge carriers in the doped state, and by extension the charge transport properties.