Substrate Modification for High‐Performance Thermoelectric Materials and Generators Based on Polymer and Carbon Nanotube Composite

Abstract

AbstractPolymer and carbon nanotube composites have aroused extensive attention for thermoelectric materials owing to the combination of low thermal conductivity of polymer and high electrical conductivity of carbon nanotubes. Surface properties of the substrate are of great importance for the charge transport behaviors of semiconducting thin films, which are less explored in thermoelectric applications. Herein, self‐assembled monolayers (SAMs) are used to modify the substrate for thermoelectric polymer composites. The trifluoromethyl (CF3)‐terminated SAM is beneficial for an improved electrical conductivity; while the SAM with amino group is found to improve their Seebeck coefficient and decrease the electrical conductivity. As a result, polymer composites on CF3‐SAM‐modified substrate show a high room‐temperature power factor of 285 µW m−1 K−2 and a large output power of 2.36 µW for thermoelectric generator at a temperature gradient of 50 K. This work demonstrates that surface modification by SAMs is a promising strategy for improving performance of thermoelectric materials and devices.