Internalization of Ionic Transport Ability of Polymer Semiconductors via Photochemical Cross-Linking

In the field of organic electronics and optics, there is rapidly growing interest in enhancing both charge transport and the ion transport properties of semiconductors, particularly in light of recent emerging technologies such as organic electrochemical transistors (OECTs) and switchable organic nanoantennas. Herein, we propose a universal method for internalizing the ionic transport properties of conventional polymer semiconductors. The incorporation of a tetrafluorophenyl azide-based photochemical cross-linker with a tetraethylene glycol bridge into poly(3-hexylthiophene) (P3HT) significantly enhances the performance and operational stability of ion-gating devices. Changes in the characteristics of the OECTs with cross-linked P3HT are minimal even after 100 cycles of operation; moreover, the cross-linked OECTs exhibit faster switching properties. In addition, the enhanced doping efficiency allows for the clear observation of plasmon resonances in nanostructured, highly doped P3HT. We believe that the proposed technique for internalizing ionic transport abilities can be applied to various ion-based semiconductor applications.