Memcapacitive properties of poly(3,4-ethylenedioxythiophene) modified electrodes

Abstract

We study the capacitive properties of poly(3,4-ethylenedioxythiophene) (PEDOT) thin layer that shows memory effects. The capacitance vs. charge plot indicates the history-dependence of the electrochemical responses, for instance capacitance with memory or memcapacitance. The variation of the charge vs. potential exhibits a hysteresis loop that is related to the non-equilibrium properties of the redox switching. The calculation of the energy that can be added to and removed from the memcapacitance system during cycling shows a reactive behavior. This property is due to the electromechanical behaviors of PEDOT film that can store and transform electrochemical energy. Indeed, the charging–discharging processes during the redox switching induce a volume and conformational change of the polymer that in turn influences its electrochemical responses. In the context of bio-inspired information processing systems or bio-inspired circuits, a 3-terminal device exhibiting non-linearity and history-dependence responses is of interest for developing organic memory-circuit elements such as an electrochemical memcapacitance.