Thermoelectric Properties of Poly(3-Alkylthiophenes)
Typical conductive polymers of poly(3-alkylthiophenes) were synthesized by oxidative polymerization. Alkyl side chains were CnH2n+1 with n=4, 6, 8, 12. The regioregularity with the HT linkage was larger than 99% based on NMR analysis. Completely regioregular head-to-tail (HT) poly(3-alkylthiophenes) were obtained. We have evaluated the effect of side chain size on the thermoelectric properties of Seebeck coefficient and electrical conductivity. The results were as follows: 1) Seebeck coefficient decreased with an increasing electrical conductivity. 2) High Seebeck coefficient >1mV/K was observed at low electrical conductivity <10-2S/cm. 3) The small side chain caused the higher electrical conductivity in the range of electrical conductivity <10- 1S/cm.
Omer Van der Biest, Michael Gasik, Jozef Vleugels
Y. Shinohara et al., "Thermoelectric Properties of Poly(3-Alkylthiophenes) ", Materials Science Forum, Vols. 492-493, pp. 141-144, 2005