Oxidation effects of poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) electrodes on high-performance organic thin-film transistors

We adjusted the conductivity of a poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT/PSS) electrode and an injection barrier between the PEDOT/PSS source/drain (S/D) electrode and a pentacene semiconductor by adding HAuCl4 to a PEDOT/PSS solution. Gold in the PEDOT/PSS S/D electrode was synthesized by a redox reaction between PEDOT/PSS and Au ions. This reaction enhances the conductivity of the PEDOT/PSS S/D electrodes and reduces the injection barrier between the PEDOT/PSS S/D electrodes and the pentacene semiconductor, and causes the field-effect mobility to increase by about 230%. As such, it is considered a very useful method of making high-performance organic thin-film transistors (OTFTs). (C) 2015 The Japan Society of Applied Physics