Multi- and All-Acceptor Polymers for High-Performance n-Type Polymer Field Effect Transistors

Multi-acceptor and all-acceptor polymers solve the fundamental challenge of achieving unipolar electron transport without compromising stability in n-type polymer field-effect transistors. By systematically replacing electron-rich donors with acceptor units, these architectures push LUMO levels below -4.0 eV and HOMO levels below -5.7 eV. Consequently, electron mobilities exceeding 7 cm² V^-1 s^-1, on/off ratios approaching 10⁷, and months-long ambient operation can be achieved. This review connects the molecular architecture to device function. We assert that short-range π-aggregation matters more than crystallinity-tight π-stacking over 5-10 molecules drives transport in rigid backbones. Device optimization through interface engineering (e.g., amine-functionalized self-assembled monolayers reduce the threshold voltages to 1-5 V), contact resistance minimization, and controlled processing transform the intrinsic material potential into working transistors. Current challenges, such as balancing the operating voltage against stability, scaling synthetic yields, and reducing contact resistance, define near-term research directions toward complementary circuits, thermoelectrics, and bioelectronics.