Polystyrenesulfonate Dispersed Dopamine with Unexpected Stable Semiquinone Radical and Electrochemical Behavior: A Potential Alternative to PEDOT:PSS

Abstract

Inspired by the p-doped PEDOT:PSS, a traditional anode modifier, we proposed to prepare polydopamine:polystyrenesulfonate (PDA:PSS) via the self-polymerization of dopamine in aqueous PSS initially. However, DA and its semiquinone radical were dispersed by PSS to form DA:PSS successfully. Interestingly, a strong electron spin resonance signal was detected in DA:PSS, suggesting the stable semiquinone radical was formed. More importantly, water-soluble DA:PSS exhibited stable and quasi-reversible electrochemical oxidation behavior, and excellent film-formation capability. Consequently, as an indium tin oxide (ITO) anode modifier, solution processed DA:PSS film showed hole injection property in organic light emitting diodes. Our results open a new avenue for the design of semiconductor and organic electronic application inspired by the electron transfer of phenol derivatives such as DA. Phenol-based organic electronic material has showed potential and it should be taken into consideration in the future.