Dye-doped poly(3,4-Ethylenedioxythiophene)-Poly(Styrenesulfonate) electrodes for the application in organic light-emitting diodes

A facile way to enhance the electrical conductivity of conductive polymers via solution-processed low-concentration doping, is suggested. An organic cationic azo dye, methyl red was used as a p-type dopant for poly(3, 4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) to realize highly conductive electrodes for organic light-emitting diode applications. By optimization of the dopant concentration, the doped PEDOT:PSS films exhibited electrical conductivities enhanced by three orders of magnitude compared to the pristine films. Ultraviolet-visible absorption spectroscopy studies indicate that charge transfer complexes between PEDOT:PSS and the dopant were formed. It was found that the dye exhibits high tendency to oxidize the polymer in a single-blend system which is necessary for the efficient doping. Our research proposes a simple and low-cost doping agent to improve the conductivity and sheet resistance of PEDOT:PSS in order to apply it as a promising electrode material for various kinds of highly flexible organic electronic devices.