Push-pull zinc phthalocyanine bearing hexa-tertiary substituted carbazolyl donor groups for dye-sensitized solar cells

Abstract

An asymmetrical, push-pull phthalocyanine bearing bulky tert-butylcarbazolyl moieties as electron donor and carboxylic acid as anchoring group was synthetized and tested as a photosensitizer in dye-sensitized solar cells (DSSC). The new photosensitizer was characterized by 1H and 13C NMR, UV-Vis and mass spectrometry. The bulky tert-butylcarbazolyl moieties avoid the aggregation of the phthalocyanine dye. DFT studies indicate that the HOMO is delocalized throughout the π-electron system of the substituted phthalocyanine and the LUMO is located on the core of the molecule with a sizable electron density distribution on carboxyl groups. The new dye has been used as a photosensitizer in transparent and opaque dye-sensitized solar cells, which exhibit poor efficiencies related to a low JscThis work was financially supported by the Kuwait Foundation for the Advancement of Science (Grant Number PN18-12-SC01) and the RSP unit general facilities of the Faculty of Science GFS (GS 01/01, GS 03/01, GS 01/03, GS 01/05, and GS 02/13) (S.M.). T.T. thanks MINECO (project CTQ2017-85393-P) and ERA-NET/European Commission/MINECO, (UNIQUE, SOLAR-ERA.NET Cofund 2 Nº 008/PCI2019-111889-2). R.D. acknowledges ANR for funding through ODYCE project. (Grant agreement No ANR-14-OHRI-0003-01). RD thanks European Research Council (ERC) for funding. This project has received funding from the European Union’s Horizon 2020 research and innovation program (grant agreement No 832606)—Project PISC