Back to the future: asymmetrical DπA 2,2'-bipyridine ligands for homoleptic copper(i)-based dyes in dye-sensitised solar cells

Guglielmo Risi; Mike Devereux; Alessandro Prescimone; Catherine E Housecroft; Edwin C Constable

doi:10.1039/d3ra00437f

Back to the future: asymmetrical DπA 2,2'-bipyridine ligands for homoleptic copper(i)-based dyes in dye-sensitised solar cells

RSC Adv. 2023 Jan 31;13(7):4122-4137. doi: 10.1039/d3ra00437f.

Authors

Guglielmo Risi¹, Mike Devereux², Alessandro Prescimone¹, Catherine E Housecroft¹, Edwin C Constable¹

Affiliations

¹ Department of Chemistry, University of Basel BPR 1096, Mattenstrasse 24a 4058 Basel Switzerland edwin.constable@unibas.ch.
² Department of Chemistry, University of Basel Klingelbergstrasse 80 CH-4056 Basel Switzerland.

Abstract

Metal complexes used as sensitisers in dye-sensitised solar cells (DSCs) are conventionally constructed using a push-pull strategy with electron-releasing and electron-withdrawing (anchoring) ligands. In a new paradigm we have designed new DπA ligands incorporating diarylaminophenyl donor substituents and phosphonic acid anchoring groups. These new ligands function as organic dyes. For two separate classes of DπA ligands with 2,2'-bipyridine metal-binding domains, the DSCs containing the copper(i) complexes [Cu(DπA)₂]⁺ perform better than the push-pull analogues [Cu(DD)(AA)]⁺. Furthermore, we have shown for the first time that the complexes [Cu(DπA)₂]⁺ perform better than the organic DπA dye in DSCs. The synthetic studies and the device performances are rationalised with the aid of density functional theory (DFT) and time-dependent DFT (TD-DFT) studies.