Thermoelectric properties of PEDOT films prepared by electrochemical polymerization

Abstract

Thermoelectric (TE) properties of flexible and freestanding poly(3,4-ethylenedioxythiophene) (PEDOT) films synthesized via galvanostatic polymerization of 3,4-ethylenedioxythiophene in propylene carbonate containing sulfated poly(bhydroxyethers) (S-PHE) as polymer electrolyte were elaborately studied. Both electrical conductivities (r) and Seebeck coefficients (S) of the PEDOT:S-PHE films were increased by decreasing the temperature (T) or by increasing the current density (J) during electrosynthesis. Possible reasons for the lack of a trade-off relation commonly observed between r and S are discussed on the basis of SEM and oxidation-level measurements. Preparation of the PEDOT:S-PHE films was optimized with respect to T and J. In addition, the oxidation level of the PEDOT:S-PHE films was controlled by potential and the change of their TE performances was discussed in conjunction with the change of chemical species involved. The power factor (PF 5 rS 2 ) of the PEDOT:S-PHE films reached 7.9 lW m 21 K 22 , leading to a dimensionless TE figure-ofmerit (ZT) of 0.013.

Effects of different electrolytes and film thicknesses on structural and thermoelectric properties of electropolymerized poly(3,4-ethylenedioxythiophene) films

“…In particular, the performance of the PEDOT lm produced using water/ methanol at the electropolymerization time of 10 s was superior to that of PEDOT lms produced using well-established, conventional electropolymerization methods. 51,52 The power factor of both PEDOT lms signicantly decreased as the electropolymerization time increased. The inset in Fig.…”

Effects of additives and post‐treatment on the thermoelectric performance of vapor‐phase polymerized PEDOT films

“…Recently, Zhang et al tuned the TE performance of PEDOT films through electrochemical control of the oxidation states. Still, the power factor of the films was merely up to 7.9 μW m −1 K −2 …”

“…14 Still, the power factor of the films was merely up to 7.9 lW m 21 K 22 . 15 In contrast, the VPP method is simple and can overcome the aforementioned issues. Therefore, it is the best method to easily manufacture highly conductive PEDOT films.…”

A review on conductive polymers and their hybrids for flexible and wearable thermoelectric applications

“…P3HT, and PBTTT showed that PDPP3T has a higher power factor (25 μW.m -1 .K -2 ) than PBTTT (14 μW.m -1 .K -2 ), and comparable to that of P3HT (30 μW.m -1 .K -2 ) [131]. It is worth mentioning that PDPP3T films had a lower σ and higher S than other films even at low doping levels [95,131]. The optimized power factor obtained for PDPP3T films is 276 μW.m -1 .K -2 .…”