Electrode material dependent p- or n-like thermoelectric behavior of single electrochemically synthesized poly(2,2 '-bithiophene) layer-application to thin film thermoelectric generator

摘要

We prepared poly(2,2'aEuro"bithiophene) (PBT) on top of Au and indium-tin oxide (ITO) bottom electrodes and determined the Seebeck coefficient in devices with Al top electrode. Negative Seebeck coefficient was observed in ITO/PBT/Al devices, whereas Au/PBT/Al devices showed positive Seebeck coefficient. This difference allowed the construction of a complete thermoelectric thin film generator with top electrode of Al and bottom electrode of ITO and Au (each one at half of the electrode area) in a single organic layer deposition step. The thermoelectric generator achieves ca. 800 mu V K-1 at room temperature, which is a very high value for conjugated polymer-based devices.