Engineered nanocarbon mixing for enhancing the thermoelectric properties of a telluride-PEDOT:PSS nanocomposite

The thermoelectric properties of telluride nanorods coated with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (Te-PEDOT:PSS) were enhanced by the addition of a small amount of a nanocarbon material such as graphene nanoparticles (GNPs) or small bundled single-walled carbon nanotubes (SSWNTs). In order to apply the nanocarbon composite material to the printing process, soluble Te-PEDOT:PSS was mixed with a small amount of nanocarbon without degrading the thermoelectric performances. The thermoelectric properties of the Te-PEDOT:PSS nanocomposites were greatly improved, especially when a rather small amount of SSWNTs was added to Te-PEDOT:PSS owing to the structural and electrical properties of the SSNWTs. The power factor of Te-PEDOT:PSS films mixed with 0.3 wt% of SSWNTs was optimized to be 206 μW m−1 K−2, with a Seebeck coefficient of 118 μV K−1 and electrical conductivity of 139 S cm−1. The fabricated thermoelectric generator (TEG) with SSWNT-mixed Te-PEDOT:PSS by spray printing showed output power of 126 nW, which is 18 times higher than that of GNP-mixed Te-PEDOT:PSS. Using the SSWNT-mixed Te-PEDOT:PSS solution, a lightweight, flexible, and highly efficient TEG was fabricated by an all-printing process, and it could generate a small amount of electricity with heat from the human body.