Transferrable, Large‐area and Highly Conductive PEDOT : PSS Film and Its Application for Flexible Thermoelectric Generators

Abstract A facile method was demonstrated to prepare large‐area (∼100 cm²), conductive poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT : PSS) dense film via post‐treatment with sulfuric acid at 160 °C on a glass substrate. This PEDOT : PSS dense films exhibited a high electrical conductivity of up to 1800 S cm⁻¹ without significantly compromising with the high humidity level, and could be easily transferred onto various flexible substrates such as plastics and paper with excellent adhesion. The conductive PEDOT : PSS dense films can be made a flexible and foldable thermoelectric module, showing an output voltage of 2.2 mV at ΔT=26 K. On the other hand, PEDOT : PSS thin films, which were prepared using a similar method, could be transferred onto the polyethylene terephthalate (PET) substrate and suitable to serve as flexible transparent electrodes for optoelectronic devices. Our simple method would hold great promise for scalability and mass production of large‐area, freestanding and conductive PEDOT : PSS polymer film for a variety of applications.