Electrochemical Fabrication and Thermoelectric Performance of the PEDOT:PSS Electrode Based Bilayered Organic Nanofilms

A novel generation of PEDOT:PSS/PPY and PEDOT:PSS/PANI bilayered nanofilms were successfully prepared by electrochemical polymerization in a mixed alcohol solution of isopropyl alcohol (IPA), boron trifluoride ethyl ether (BFEE), and polyethylene glycol (PEG), based on a PEDOT:PSS nanofilm electrode. The structure, electrochemical, optical, and morphology of the as- formed films were systematically investigated by FT-IR, cyclic voltammetry (CV), UV-vis, and SEM. Thermoelectric (TE) investigations revealed that the electrical conductivity of the films was increased with the increasing BFEE proportion, and the values for PEDOT:PSS/PPY and PEDOT:PSS/PANI were 97.1 and 212.6 S cm-1 in the case of 30% BFEE. Meanwhile, the Seebeck coefficient kept at a relative high and stable level, with the maximum value of 23.3 pV K-1 for PEDOT:PSS/PPY and 27.8 pV K-1 for PEDOT:PSS/PANI. It was encouraging that the power factor of PEDOT:PSS/PANI films could reach up to be 12.0 pW m-1 K-2, obtaining the maximum ZT value of 2.12×10-2 by estimates. Furthermore, as a new-found set of pure organic bilayered nanostructure materials, they may possess a great potential for realizing wide applications in TE or other organic electronics fields.