Abstract: Must link to publisher version. Publisher source must be acknowledged with citation ; Thermoelectric materials have garnered significant interest for their potential to efficiently convert waste heat into electrical energy at room temperature without moving parts or harmful emissions. This study investigated the impact of the HOMO-LUMO (H-L) gap on the thermoelectric properties of three distinct classes of organic compounds: conjugated aromatics (isoindigos (IIGs)), quinoidal molecules (benzodipyrrolidones (BDPs)), and donor-acceptor systems (bis(pyrrol-2-yl)squaraines (BPSs)). These compounds were chosen for their structural simplicity and linear π-conjugated conductance paths, which promote high electrical conductance and minimize complications from quantum interference. Single-molecule thermoelectric measurements revealed that despite their low H-L gaps, the Seebeck coefficients of these compounds remain low. The alignment of the frontier orbitals relative to the Fermi energy was found to play a crucial role in determining the Seebeck coefficients, as exemplified by the BDP compounds. Theoretical calculations support these findings and suggest that anchor group selection could further enhance the thermoelectric behavior of these types of molecules ; N.B. thanks the School of Engineering, University of Warwick, studentships for Ph.D. funding. H.S. acknowledges UKRI for Future Leaders Fellowship numbers MR/S015329/2 and MR/X015181/1. S.S. acknowledges Leverhulme Trust for Early Career Fellowship no. ECF-2018-375. P.C. and S.M. are grateful for financial assistance in the framework of the projects PID2022-141433OB-I00 and TED2021-131318B-I00 funded by MCIN/AEI/10.13039/501100011033 and European Union “NextGenerationEU”/PRTR as well as Gobierno de Aragón through grant E31_23R with European Social Funds (Construyendo Europa desde Aragón). P.B. acknowledges financial support from Spanish MICINN ref PRE2019-091388. N.A. acknowledges funding by Spanish MICINN (grant PID2020-114880GB-I00 and “Maria de Maeztu” ...
Processing Request
No Comments.