n-Type ion gel gated vertical organic electrochemical transistors based on benzodifurandione-based Oligo(p-phenylene vinylene)s

초록

Organic electrochemical transistors (OECTs) using aqueous gate dielectrics have garnered significant interest for bioelectronic applications. However, their viability for long-term use in neuromorphic computing and synaptic devices is limited due to their short-term functionality. In this study, we synthesize two benzodifurandione-based oligo ( p -phenylene vinylene) polymers, BDOPV-TCNVT and ClBDOPV-TCNVT, and investigate their electrochemical transistor properties using quasi -solid-state ion gel -gated vertical OECTs ( v -OECTs). Compared to BDOPV-TCNVT, the chlorinated ClBDOPV-TCNVT demonstrates lower frontier molecular orbitals and easier electrochemical doping. The higher volumetric capacitance of as -spun ClBDOPV-TCNVT (1.94 F cm -3 ) compared to as -spun BDOPV-TCNVT films (1.49 F cm -3 ) is mainly attributed to the easier ion infiltration resulting from its lower crystallinity with mixed chain orientation. The quasi -solid-state v -OECTs based on both polymers (as -spun) exhibit transconductance ( g m ) of 0.06 -0.08 mS. Following thermal treatments, the g m gradually decreases for both polymers due to enhanced edge -on ordering with tight interchain packing, hindering ion penetration. Despite the poor electrochemical doping by quasi -solid-state ion gel gated dielectrics, the enlarged area and decreased channel length in v- OECTs (compared to parallel OECTs) can enhance the g m . Further optimization of v- OECTs requires tailored material designs specifically suited for efficient vertical charge transport together with ion infiltration.

키워드