Donor-Glycolated Quinoidal Polymers Enable Fast N-Type Organic Electrochemical Transistors

Fast, stable n-type organic mixed ionic-electronic conductors remain scarce. We report a donor glycolated, quinoidal design that facilitates efficient n-doping and spatially separates hydrophilic side chains from n-doping sites to preserve electronic pathways. The resulting polymer PQ-gT, synthesized from a glycolated bithiophene donor and a quinoidal bifuran-dione acceptor, exhibits high mixed conduction with a figure of merit of µC* = 10.9 F cm⁻¹ V⁻¹ s⁻¹. In planar accumulation-mode organic electrochemical transistors (OECTs), it exhibits nearly symmetric sub-millisecond transients with switching on- and off-times of τ_on/τ_off = 0.5/0.2 ms. These values represent the fastest operation for this type of device architecture. Partial donor replacement with dialkoxybithiazole tunes packing and suppresses swelling, raising µC* to 21.5 F cm⁻¹ V⁻¹ s⁻¹ at 25% substitution, albeit with slower switching. In vertical OECTs, PQ-gT supports balanced ambipolar operation with ∼1 ms switching and enables a single-material complementary inverter (gain ≈ 40 V V⁻¹ at V_IN < 100 mV) that is stable over 10 000 cycles and functional up to 200 Hz. This donor-glycolated quinoidal strategy furnishes intrinsically fast, aqueous-stable n-type organic mixed ionic-electronic conductors for bioelectronic circuits.