Post-treatment of Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) Films for Flexible Transparent Electrodes

Abstract

The rapid development of novel organic technologies has led to significant applications of the transparent and flexible organic electronic device such as light-emitting diodes, solar cells, and field-effect transistors. There is a great need for conducting polymers with high flexibility, transparency and conductivity to act as the charge transport layer or electrical interconnect in organic devices. Poly(3,4-ethylenedioxythiophene): poly(styrenesulfonic acid) (PEDOT:PSS), well-known as the most remarkable conducting polymer, has this role owing to its good film-forming properties, high transparency and tunable conductivity. Although the posttreatment of PEDOT:PSS films with concentrated sulfuric acid induces dramatic conductivity improvement, it has been still a great challenge to fabricate highly conductive PEDOT:PSS films on plastic substrates due to the substrate damage. Herein, we reports an efficient and direct solution process to improve electrical conductivities of PEDOT:PSS films ( >2000 S/cm) on flexible substrate for flexible and transparent electrode. We confirmed that the post-treatment with proper solution formulations enabled the conductivity enhancement in PEDOT:PSS films, which could be attributed to both structural rearrangement in PEDOT and removal of unnecessary PSS. The PEDOT:PSS film shows great transparency and flexibility. Furthermore we found that our method can make the pattern-able PEDOT:PSS film on flexible poly(ethylene terephthalate) substrate which has great potential to apply to the flexible and transparent electronics as electrodes.