Programmable Polymer Memory Device Based on Hydrophilic Polythiophene and Poly(ionic liquid) Electrolyte

A three‐terminal non‐volatile memory device with the configuration of an organic thin‐film transistor (OTFT) is constructed from two polymeric layers by using the conventional solution‐coating process. It consists of a hydrophilic polythiophene, regioregular poly(3‐carboxypentylthiophene) (P3CPT) as the active layer and a poly(ionic liquid), poly[1‐(4‐vinylbenzyl)‐3‐butyl imidazolium tetrafluoroborate] (PVBIT) as a polyelectrolyte layer. The conductivity of the polythiophene layer can be reversibly switched between high and low conductance states with “write” and “erase” bias at +3 and ?3 V, respectively. The retention time of the ON state is up to 1.6 × 10⁴ s and the write–read–erase–read switching is stable over 100 cycles. In addition, an instantaneous response and a fast switching speed are observed by simultaneous monitoring of both the “write” and “read” operations. All these results indicate that the device developed possesses potential applications as alternative solid‐state non‐volatile memory devices.