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

Tae-Hoon Kim; Jae Gyu Jang; Sung Hyun Kim; Jong-In Hong

doi:10.1002/advs.202302922

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

Adv Sci (Weinh). 2023 Nov;10(33):e2302922. doi: 10.1002/advs.202302922. Epub 2023 Oct 20.

Authors

Tae-Hoon Kim¹, Jae Gyu Jang^{1

2}, Sung Hyun Kim², Jong-In Hong¹

Affiliations

¹ Department of Chemistry, Seoul National University, Seoul, 08826, South Korea.
² Department of Carbon Convergence Engineering, Wonkwang University, Iksan, 54538, South Korea.

Abstract

Hybridizing single-walled carbon nanotubes (SWCNTs) with π-conjugated organic small molecules (π-OSMs) offers a promising approach for producing high-performance thermoelectric (TE) materials through the facile optimization of the molecular geometry and energy levels of π-OSMs. Designing a twisted molecular structure for the π-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 π-OSM hybrid exhibits a high Seebeck coefficient of 110.4 ± 2.6 µV K^-1 , leading to a significantly improved power factor of 2,136 µW 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 π-OSM hybrid. The study highlights the promising potential of optimizing molecular engineering of π-OSMs for hybridization with SWCNTs to create next-generation, efficient TE materials.

Keywords: ZT enhancements; carbon nanotubes; charge carrier transports; molecular engineering; thermoelectric materials; π-conjugated organic small molecules.

Abstract

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