Improving the Thermoelectric Performance of Solution-Processed Polymer Nanocomposites by Introducing Platinum Acetylides with Tailored Intermolecular Interactions

Abstract Hybrid thermoelectric (TE) materials incorporated with the conjugated polymers and single-walled carbon nanotubes (SWCNTs) are promising to decouple the intractable interrelation of the key TE parameters, and therefore yield considerable composites for solution-processable flexible TE generators. However, the disordered intermolecular interactions and inefficient overlap of the frontier molecular orbitals between the polymer backbones and the SWCNTs largely degenerate the TE properties of the composites. Herein, we demonstrate an efficient strategy to regulate their intermolecular π-π interactions by introducing heavy metal atoms (platinum) along with tailored π-ligands to reconstruct the main chain of the incorporated polymers. Consequently, both the calculated binding energy and the observed Dexter energy transfer process between the SWCNTs and the polymers are remarkably increased with the insertion of platinum, indicating significantly enhanced π-π interactions between the two. Meanwhile, their self-aggregation can be effectively restrained by the large steric hindrance groups of tributyl phosphine ligands synchronously. Therefore, a high power factors of over 464 μW m−1 K−2 (r.t.) and a high output power approaching to 2200 nW (ΔT = 70 K, 10 legs) can be achieved by the P(HTh-Pt)/SWCNT-based TE generators, which is almost two times as high as the homologous P3HT one without platinum.