Green DES mixture as a surface treatment recipe for improving the thermoelectric properties of PEDOT:PSS films

• DES mixture (ChCl/urea) was firstly used as a surface treatment reagent for improving thermoelectric properties of PEDOT:PSS films.
• DES surface treatment achieves simultaneous increases in electrical conductivity and Seebeck coefficient.
• Higher temperature leads to higher TE performance due to the change of physical nature of DES.
• Surface treatment by DES in combination with DMSO further optimized the TE performance of PEDOT:PSS films.

Green DES (ChCl/urea fluid) as a novel surface treatment reagent has been proposed for improving the thermoelectric (TE) performance of PEDOT:PSS films and demonstrated satisfying effects as expected. Simultaneous increases were found in the electrical conductivity and Seebeck coefficient, which achieved further improvement by raising the treating temperature. This additional enhancement was probably attributed to that higher temperature led to decreased viscosity thus a better interaction between the DES mixture and the film surface. The maximum electrical conductivity and Seebeck coefficient were found at 120 °C, reaching 85.6 S cm−1 and 30.1 μV K−1. Further TE improvement was obtained when DMSO was introduced to make a mixture with DES at different ratios to act as the treatment reagent, giving rise to an optimized power factor of 25.26 μW m−1 K−2 with the corresponding electrical conductivity and Seebeck coefficient being 424.2 S cm−1 and 24.4 μV K−1, respectively.

Figure optionsDownload as PowerPoint slide