Purification of PEDOT:PSS by Ultrafiltration for Highly Conductive Transparent Electrode of All‐Printed Organic Devices

A highly conductive, air stable and scalable poly(3,4-ethylenedioxythiophene) (PEDOT): poly(4-styrenesulfonate) (PEDOT:PSS) are prepared by using mass production ultrafiltration. By effectively removing excess PSS and various reaction impurities using repeated 100 nm pore membrane filtration, purified PEDOT:PSS exhibit conductivity as high as 2000 S cm−1.