Thermoelectric properties of PEDOT nanocomposites with electrochemically tuned oxidation state

Room temperature thermoelectric application of conjugated polymer poly(3,4-dioxyethylenthiofene) (PEDOT) has recently gained a lot of attention due to its peculiar features such as low cost, safety and possibility to easily process it, which makes it an interesting alternative to tellurides commonly used in this field [1]. In spite of these advantages, nowadays the main drawback of PEDOT is its low thermoelectric efficiency that has still to be successfully addressed. Two interesting paths have been explored: the first involves the development of PEDOT based nanocomposites [2], including nanostructured material into the polymer, in order to generate nanometric size related effects (e.g. energy filtering). The second one deals with the optimization of the oxidation state of the polymer, since it sets its electronic properties [3]. Considering both strategies, we prepared PEDOT nanocomposites, embedding inorganic nanoparticles (INPs) of Mn 3 O 4 and CuO (Figure 1) in different concentration, and achieved a fine tuning of the oxidation state through an electrochemical path. This combined strategy allowed to analyse the dependence of the electric and thermoelectric properties on the applied electrochemical potential (Figure 2). Results will be discussed, showing the correlation between the two transport coefficients and the nanocomposite oxidation state.