Hybrids composites of NCCO/PEDOT for thermoelectric applications

Abstract

Organic materials are becoming a realistic roadway to fabricate efficient thermoelectric devices using environmental friendly materials. Such requirements are actually fulfilled by thermoelectric generators operating by conducting polymers, but also by hybrid materials. The combination of organic+inorganic compounds may exhibit a high electrical conductivity and Seebeck coefficient as well as lower thermal conductivity in order to efficiently generate thermoelectric power. In these hybrid compounds, perovskite-type oxides are a suitable election for the inorganic part since they have a high Seebeck coefficient although their electrical conductivity is usually low. Blending them with conducting polymers would be a good procedure to improve their thermoelectric properties. In this work, hybrids materials formed by a cobalt perovskite, Nd1-xCaxCoO3 (NCCO), have been combined with the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) doped with either poly(styrenesulfonate) (PSS) or tosylate (Tos). The electrical conductivity, Seebeck coefficient, X-ray diffraction and scanning electron microscopy have been used to characterize the resulting material. A thermoelectric power up to 1.0μW/K2m has been obtained for NCCO/PEDOT:Tos at a 95/5 mass ratio.