ICT2014 Abstracts

The fact that the polymer PEDOT/PSS can conduct electrical current when casted as thin films, drew a big attention from researchers interested in thermoelectric materials. PEDOT/PSS thin films are popular for organic electronic applications such as organic sensors, organic light diodes and organic solar cells. They were found to be front runners in thermoelectric materials, with a record thermoelectrical figure of merit of 0.42. The thermoelectrical properties of these films were found to be enhanceable through the addition of different solvents to the PEDOT/PSS. Such solvents are dimethyl sulfoxide (DMSO), N,N-dimethyl formamide (DMF), tetrahydrofuran (THF), water (as pristine solvent), ethylene glycol, and ionic liquids. A Deep Eutectic Solvent (DES), as ionic liquids’ analogue, synthesized from Ethylene Glycol and an ammonium salt, is applied in this work as an additive to the PEDOT/PSS to enhance the thermoelectrical properties of the thin films produced from the mixture solutions. The Deep Eutectic Solvent was added in different weight percentages to PEDOT/PSS to investigate the benifits of increasing the concentration of the added DES on the electrical conductivity of the thin films. The films were produced by spin-coating technique, and annealed at three annealing temperatures (80, 100, and 150 ^oC). Enhancement in the electrical conductivity is observed when the results of films of pure PEDOT/PSS were compared with results of films treated with DES. The highest electrical conductivty for a pure PEDOT/PSS film was observed when the annealing temperature was 80 ^oC, with a conductivity of 0.9 S/cm. The conductivty was enhanced more than 23 folds to 15.97 S/cm when treated with the DES.