Humidity-dependent thermoelectric properties of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)

Abstract

Thermoelectric properties of poly(3,4-ethylenedioxythiophene) doped by different amounts of poly(styrene sulfonate) (PSS) were tested under various humidity conditions. The thermoelectric power factor was found to increase with humidity, with a larger increase observed for samples with less PSS content. For these samples with low PSS content, the Seebeck coefficient and electrical conductivity were observed to simultaneously increase as humidity was increased. Thermal conductivity was observed to increase with increasing humidity for samples with low PSS content and decrease for samples with high PSS content. Measurements on thick films soaked by various polar solvents likewise showed an enhancement in power factor.