Rational primary structure design for boosting the thermoelectric properties of semiconducting carbon nanotube networks

The precise control of carbon nanotube structures plays a crucial role in understanding their intrinsic transport as well as in utilizing them for energy harvesting applications. In this paper, we elucidate that slight differences in the purity and diameter distribution of semiconducting single-walled carbon nanotubes (sc-SWCNTs) lead to the significant modulation of thermoelectric transport in their networks. Conducting polymers examined here enable the sorting of the sc-SWCNTs with desired purity and diameter distribution, as well as fixed solid state morphology. Particularly, the approximately tenfold enhancement of thermoelectric power factors is achieved by improving sc-SWCNT purity from 94% to 99% and increasing mean diameters from 1.0 to 1.2 nm. This work provides a rational design for boosting the thermoelectric properties of sc-SWCNT networks.