Solution-Processed Carbon Nanotube Buckypapers for Foldable Thermoelectric Generators

Freestanding single-walled carbon nanotube (SWCNT) buckypapers with thicknesses of ∼30 μm are fabricated using a simple bar-coating process. The Seebeck coefficient and electrical conductivity of the SWCNT buckypapers are affected by the composition of the dispersion solvent mixture. The maximum p-type power factor of a SWCNT buckypaper is 411 ± 13 μW m–1 K–2. The inverse relationship between the Seebeck coefficient and electrical conductivity of the SWCNT buckypapers may be explained by the number density of junctions between the SWCNT bundles. Using the SWCNT buckypapers, which can be cut, folded, and pasted, a foldable thermoelectric generator is fabricated. The thermoelectric generator folded to an area of 2.25 cm2 exhibits a maximum power of 10.3 μW at a vertical temperature difference of 30 K.