Thermoelectric Properties of Conducting Polymer Nanowire-Tellurium Nanowire Composites

In recent years, the thermoelectric properties of inorganic/polymer composites have been markedly improved. However, the enhancement mechanism in inorganic/polymer composites is still far from clear. In this work, we fabricate a novel type of thermoelectric composite by mixing high-mobility poly(3,4-ethylenedioxythiophene) nanowire with tellurium nanowire and investigate the thermoelectric properties by varying the loading of tellurium nanowires and the underlying enhancement mechanism. We find that the addition of tellurium nanowire can enhance the thermoelectric power factor of inorganic/polymer nanowire composites by similar to 40%. We, for the first time, quantitatively interpret the effect of energy filtering on thermoelectric power factor enhancement in polymer inorganic composites by employing the hopping transport theory. In contrast to the series/parallel connected model, we determine that the energy filtering is more feasible to physically explain the thermoelectric enhancement. It can numerically explain the enhancement in Seebeck coefficient, electrical conductivity, and power factor. We believe it is assigned to the high carrier mobility in nanowire composites and proper energy barrier at polymer/inorganic interfaces.