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

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.