Utilizing Cooperative Proton–Electron Mixed Conduction Induced via Chemical Dedoping of Self‐Doped Poly(3,4‐ethylenedioxythiophene) Nanofilms for In‐Material Physical Reservoirs

Abstract In this study, an intrinsic ion–electron (hole) coequally conductive state is introduced, induced by de‐doping in self‐doped poly(3,4‐ethylenedioxythiophene) (S‐PEDOT) nanofilms, enhances the performance of in‐material physical reservoirs (PRs) through the cooperative utilization of both carriers. A chemical dedoping modulates the electrical characteristics of the S‐PEDOT PRs. Impedance spectroscopy under controlled relative humidity (RH) conditions reveals that the predominant conducting carriers of the S‐PEDOT nanofilms change systematically depending on the RH. Under low RH, the dominant carriers are holes. At a moderate RH (60–80%), the S‐PEDOT nanofilm exhibits a hole–proton mixed conducting state. A further increase in RH leads to predominantly proton carrier conduction. Moreover, the PR performance of the S‐PEDOT nanofilms is evaluated by wave generation and nonlinear autoregressive moving average (NARMA) tasks. The S‐PEDOT PRs display the best performance at RHs ranging from 60% to 80% (mixed conducting state). Therefore, it is concluded that this high PR performance is attributed to the complex dynamics originating from the cooperative hole–proton mixed conducting state of the S‐PEDOT nanofilms. The results obtain in the present study are the first report of PRs using intrinsically ion–electron mixed conducting states, paving the way for the development of high‐performance material‐based PRs.