poly (3,4-ethylene-dioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) based solution
processable transparent electrodes have attracted great interests to replace ITO. In the past, various methods have been
developed for improving the conductivity of PEDOT:PSS electrodes, including addition of solvents [8], solvent posttreatment
[9], and using a multi-layer structure [10].The sheet resistance of the most conductive PEDOT:PSS films could
be as small as that of commercial ITO electrodes on plastic substrates, but there is still much room for further
improvements to avoid undesired voltage drops and Joule heating in large area applications [11]. In this work, ITO-free
OPV devices are achieved by adopting our recently developed all solution processed polymer/metal hybrid transparent
electrode technology.