A flexible, printable, thin-film thermoelectric generator based on reduced graphene oxide–carbon nanotubes composites

Thermoelectric energy harvesting is one of the keystones of modern green renewable energy generation. Unfortunately, most conventional state-of-the-art inorganic semiconductor thermoelectric generators are expensive, fragile, and not flexible. Considering these limitations, we developed a flexible printable thermoelectric generator (TEG) with both n-type and p-type organic composites of reduced graphene oxide, carbon nanotubes, poly(3,4-ethylenedixoythiphene)–polystyrene sulfate, and lead sulfide composite materials. We constructed a TEG of ten alternating n–p pairs as a prototype with an effective area of 1.4 cm² each, which generated 13 mV thermovoltage at operating temperature difference of 77 °C. It demonstrates that its fabrication is scalable, printable, and relatively simple, and the resultant structure is flexible, conformal, and reconfigurable.