Micron-scale patterning of high conductivity poly(3,4- ethylendioxythiophene):poly(styrenesulfonate) for organic field-effect transistors

We report the use of interlayer lithography for the micron-scale patterning of high conductivity poly(3,4-ethylendioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The interlayer method was used to fabricate PEDOT:PSS source and drain electrodes with conductivities >360 S/cm and pattern gaps≥4 lm for top-gate/bottom-contact organic field-effect transistors (OFETs). p-Type OFETs based on 2,8-difluoro-5,11-bis(triethylsilylethynyl)-anthradithiophene (diF-TESADT) and blends of diF-TESADT with poly(tri-arylamine) (PTAA) exhibited high hole mobilities of up to 1 and 0.25 cm²/V s, respectively, while ambipolar OFETs based on methanofullerene [6,6]-phenyl-C61-butyric acid methyl-ester (PCBM) exhibited respective electron and hole mobilities of 0.05 and 0.005 cm²/V s. Complementary voltage inverters based on the diF-TESADT/PTAA and PCBM OFETs exhibited excellent operating characteristics with wide noise margin and high signal gain, indicating that the interlayer method offers a viable route to cost efficient, solution-processed, and flexible organic electronics.