Effect of addition of poly(ethylene glycol) on electrical conductivity of poly(3,4-ethylenedioxythio

By mixing various concentrations of poly (ethylene glycol), a series of poly(3,4-ethylenedioxythiophene)- poly(styrenesulfonate) composite thin films were prepared. The electrical conductivity of the PEDOT-PSS/PEG thin films was measured by the four-probe method. Experimental results showed that the inclusion of poly(ethylene glycol) influenced the electrical conductivity of PEDOT-PSS film significantly. With the increase of PEG concentrations, the electrical conductivity sharply increased to reach a maximum and then slowly decreased down. Furthermore, the PEG molecular weight and environment temperature also played important roles on the electrical conductivity of PEDOT-PSS/PEG thin films. A good linear relationship was found between ln -DC and T -1/2 within the entire temperature range detected.