Giant Seebeck effect in an undoped single crystal of 2,5,8-triphenylbenzo[1,2-b:3,4-b':5,6-b'‘]trifuran

Abstract The application of 2,5,8-triphenylbenzo[1,2-b:3,4-b':5,6-b'‘]trifuran (Ph3-BTF) as a thermoelectric generator is demonstrated. An undoped single crystal of Ph3-BTF exhibited a giant Seebeck effect (GSE) with a large negative Seebeck coefficient of up to −239 mV K−1 at a base temperature of 350 K. Ph3-BTF features a small reorganization energy and tight molecular packing in the single crystal (π–π stacking distance: 3.32 Å), which may contribute to the observed GSE.