Electrochemical characterization of the solvent-enhanced conductivity of poly(3,4-ethylenedioxythiophene) and its application in polymer solar cells

The influence of solvent on the electrochemical property and conductivity of PEDOT has been investigated by electrochemical and physical characterizations. The PEDOT treated with different solvents reveals a different reversibility of ionic transport and cycling stability, which is associated with the conformational rearrangement from aggregated to linear polymer chains, as evidenced from atomic force microscopy (AFM). The conductivity of the PEDOT thin film can also be enhanced while the degree of linear polymer chains is higher. The application of highly conductive PEDOT thin film as a buffer layer in the polymer photovoltaic devices was realized. A PCE of 4.27% for photovoltaic devices based on P3HT-PCBM under simulated sun light is achieved by using a PEDOT thin film treated with DMSO. © 2009 The Royal Society of Chemistry.