Thermopower enhancement in conducting polymer nanocomposites via carrier energy scattering at the organic-inorganic semiconductor interface

The energy-filtering effect was successfully employed at the organic-inorganic semiconductor interface of poly(3-hexylthiophene) (P3HT) nanocomposites with the addition of Bi₂Te₃ nanowires, where low-energy carriers were strongly scattered by the appropriately engineered potential barrier of the P3HT-Bi₂Te₃ interface. The resulting P3HT-Bi₂Te₃ nanocomposites exhibited a high power factor of 13.6 μW K^-2 m^-1 compared to that of 3.9 μW K^-2 m^-1 in P3HT. The transport characteristics of nanocomposites, including the carrier concentration, mobility, and energy-dependent scattering parameter, were revealed by the experimental measurements of electrical conductivity, Seebeck coefficient, and Hall coefficient to quantitatively elucidate the carrier energy scattering at the P3HT-Bi₂Te₃ interface. The ability to rationally engineer the organic-inorganic semiconductor interfaces of polymer nanocomposites to achieve an improved Seebeck coefficient and power factor provides a potential route to high-performance, large-area, and flexible polymer thermoelectric materials.