Enhanced Thermoelectric Properties of Coated Vanadium Oxynitride Nanoparticles/PEDOT:PSS Hybrid Films

Thermoelectric (TE) materials transform thermal energy into electricity, which can play an important role for global sustainability. Conducting polymers are suitable for the preparation of flexible TE materials because of their low-cost, lightweight, flexible, and easily synthesized properties. Here, we fabricate organic-inorganic hybrids by combining vanadium oxynitride nanoparticles coated with nitrogen-doped carbon (NC@VNO) and poly(3,4-ethylenedioxy thiophene):poly(styrene sulfonate) (PEDOT:PSS). We find that the electrical conductivity, Seebeck coefficient, and power factor of the NC@VNO/PEDOT:PSS film can be enhanced up to 4158 S/cm, 45.8 μV/K, and 873 μW/mK² at 380 K, respectively. The large enhancement of the power factor may be due to the facilitation of the interfacial charge transport tunnel between the NC@VNO nanoparticles and PEDOT:PSS. The improvement of the Seebeck coefficient may be due to the energy filter effect as induced by interfacial contact and internal electric field between the NC@VNO nanoparticles and PEDOT:PSS. Our measurement suggests that the high binding energy of pyrrolic-N enhances the Seebeck coefficient, and the high binding energy of oxide-N increases electrical conductivity.