PEDOT:PSS/Graphene Composites for OLEDs and Conductive Trails

This study investigates the enhancement of electrical conductivity in poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) thin films through the incorporation of few-layer graphene (mG). Nanocomposite films were prepared by spin coating from liquid dispersions containing approximately 10 wt% mG. The resulting films exhibited high optical transmittance (~80%) and significantly reduced sheet resistance, reaching values as low as 1.8 kΩ/□. These improvements in electrical and optical performance are attributed to enhanced charge transport arising from π–π interactions between graphene and PEDOT:PSS, as well as conformational changes in the polymer chains. The PEDOT:PSS/mG composites were successfully applied both as conductive inks, forming conductive trails capable of powering a light-emitting diode (LED), and as hole transport layers in organic light-emitting diodes (OLEDs). Comprehensive optical and electrical characterization of the composite films and the corresponding OLED devices demonstrates the strong potential of PEDOT:PSS/mG nanocomposites for use in flexible and printed electronic applications.