Ionic Liquids Functionalized PEDOT:PSS Channel: An Ideal Strategy for Both Accumulation and Depletion Mode OPECT...

Developing a universal channel for organic photoelectrochemical transistors (OPECTs) diversity remains a challenge worthy of further exploration. Herein, an ionic-liquid-functionalized poly(ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was adopted as the channel material for OPECT devices, enabling the universal application of both accumulation and depletion mode OPECT devices with excellent signal amplification capabilities. This was attributed to the fact that the ionic liquid tris(2-hydroxyethyl)-methylammonium methylsulfate ([MTEOA][MeOSO₃]) could undergo ion exchange with PEDOT:PSS and induce molecular rearrangement in the PEDOT chains, which in turn facilitates the formation of conductive pathways between PEDOT chains and substantially enhances the electrical conductivity. As a proof of concept, the PEDOT:PSS/[MTEOA][MeOSO₃] channel was validated in the application of the accumulation-mode OPECT sensing by integration with a mZIF-8/Au@COF_TFPB-DBD photocathodic gate. This work not only offers a reference for the construction of a universal OPECT platform but also presents significant opportunities for the further development of OPECT sensing technology, thus broadening its application prospects.