Problems of conductivepolymers as thermoelectric materials

Y. Shinohara¹, K.Ohara¹, Y. Imai², Y. Isoda², H. Nakanishi¹

¹Institute ofMultidisciplinary Research for Advanced Materials, Tohoku University,

2-1-1, Katahira, Aoba-ku, Sendai, Miyagi980-8577, Japan

²National Institute forMaterials Science, 1-2-1, Sengen, Tsukuba, Ibaraki 305-0047, Japan

Now we meet with worseningglobal environment. Our prompt action to stop the worsening is demanded forposterity. New materials and devices are no exception. We need materials anddevices to reduce the environmental burden through their life cycles of miningore, refining raw material, material fabrication, product manufacture, productuse, separate and recovery, recycling and disposition. Most of inorganicthermoelectric materials have many problems such as that 1) main elements areheavy metals, 2) fabrication energy of materials is high, 3) manufacturing energyof thermo-modules is very high, 4) separate and recovery is difficult, and soon.

Polymers, which arecharacterized by light element system, abundant resources, low fabrication andproduction energy, possible separate and recovery, are superior to inorganicmaterials concerning to environmental burden. The problem, however, is very lowSeebeck coefficient as well as low electrical conductivity. Fatal is the lowSeebeck coefficient. We must resolve why Seebeck coefficient is too low torealize polymer thermoelectric materials. In this presentation, we report someresults on the experimental relationships between Seebeck coefficient andconductivity of some conductive polymers.