Thermoelectric Behavior of Conducting Polymers Hybridized with Inorganic Nanoparticles

We introduce a simple and facile method for fabrication of a poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/germanium nanoparticle (Ge NP) composite film with enhanced thermoelectric conversion efficiency. The Ge NP were prepared by mechanical grinding and mixed with solution-phase PEDOT:PSS. The film processability of the composite was excellent and the overall process did not involve complicated synthetic procedures. The thermoelectric power factor of the composite film was optimized to 31.20 μW m⁻¹ K⁻² by controlling the composition. The composite film had an exceptionally low thermal conductivity of 0.417 W m⁻¹ K⁻¹ and the thermoelectric figure of merit (ZT) was maximized at 0.0223 at room temperature. The mechanism for the improvement of the thermoelectric conversion efficiency was investigated by introducing energy models based on interfacial scattering of charge carriers and phonons. We expect that this robust method could lead to a facile route for design of organic–inorganic composite-based thermoelectric materials.