Synthesis of Novel Conjugated Polyelectrolytes for Organic Field-Effect Transistors Gate Dielectric Materials

Conjugated polyelectrolytes and their neutral precursors: aminoalkyl-substituted polyfluorenes (PFNs) with different 4,7-bis(N-methylpyrrol-2-yl)-2,1,3-benzothiadiazole (PBT) contents were synthesized by Suzuki coupling reaction. Their quaternized ammonium polyelectrolyte derivatives were obtained through a post-polycondensation treatment on the terminal amino groups. The resulting copolymers PFNBr-PBT are soluble in polar solvents such as methanol, DMF, and DMSO. Using the conjugated polyelectrolytes PFNBr-PBT5 as gate dielectric material, poly(3-hexylthiophene) (P3HT) -based field-effect transistors (FETs) show a high drain current of almost 4.5 mA within a gate voltage of only -3 V. The calculated hole mobility of P3HT is about 0.58 cm(2) . V-1. s(-1).