The role of substrates and electrodes in inkjet-printed PEDOT:PSS thermoelectric generators

Abstract

In this work, we leverage the versatility of inkjet printing technology with a commercial PEDOT:PSS ink to evaluate the thermoelectric performances of films deposited on different substrates (polyimide foils, glass, and silicon oxide). The substrate wettability and the printing direction were found to strongly impact the resulting thermoelectric performances. In particular, a relatively high Seebeck coefficient of 10 μV K⁻¹ was achieved along the direction parallel to the printing direction on the silicon oxide substrate. Furthermore, the power factor was found to be almost three times higher in films inkjet-printed on the silicon oxide substrate compared to that on the polyimide substrate. Finally, to investigate the thermoelectric performances of a fully inkjet-printed flexible thermoelectric device, we compared the role of e-beam evaporated vs. inkjet-printed electrodes.