Molecular Engineering for Enhanced Thermoelectric Performance of Single-Walled Carbon Nanotubes/π-Conjugated Organic Small Molecule Hybrids

Hybridizing single-walled carbon nanotubes (SWCNTs) with pi-conjugated organic small molecules (pi-OSMs) offers a promising approach for producing high-performance thermoelectric (TE) materials through the facile optimization of the molecular geometry and energy levels of pi-OSMs. Designing a twisted molecular structure for the pi-OSM with the highest occupied molecular orbital energy level comparable to the valence band of SWCNTs enables effective energy filtering between the two materials. The SWCNTs/twisted pi-OSM hybrid exhibits a high Seebeck coefficient of 110.4 +/- 2.6 mu V K-1, leading to a significantly improved power factor of 2,136 mu W m(-1) K-2, which is 2.6 times higher than that of SWCNTs. Moreover, a maximum figure of merit over 0.13 at room temperature is achieved via the efficient TE transport of the SWCNTs/twisted pi-OSM hybrid. The study highlights the promising potential of optimizing molecular engineering of pi-OSMs for hybridization with SWCNTs to create next-generation, efficient TE materials.