A Heteroleptic Bis(tridentate) Ruthenium(II) Platform Featuring an Anionic 1,2,3-Triazolate-Based Ligand for Application in the Dye-Sensitized Solar Cell

Abstract

A series of bis(tridentate) ruthenium(II) complexes featuring new anionic 1,2,3-triazolate-based tridentate ligands and 2,2':6',2''-terpyridine is presented. For a complex equipped with carboxy anchoring groups, the performance in a dye-sensitized solar cell is evaluated. The title complexes are readily synthesized and can be decorated with alkyl chains utilizing azide-alkyne cycloaddition methods, in order to improve the device stability and allow the use of alternative electrolytes. On account of the strong electron donation from the 1,2,3-triazolates, the complexes exhibit a broad metal-to-ligand charge-transfer absorption (up to 700 nm), leading to an electron transfer toward the anchoring ligand. The lifetimes of the charge-separated excited states are in the range of 50 to 80 ns. In addition, the ground- and excited-state redox potentials are appropriate for the application in dye-sensitized solar cells, as demonstrated by power conversion efficiencies of up to 4.9% (vs 6.1% for N749).

ZnO Nanostructures for Dye‐Sensitized Solar Cells Using the TEMPO+/TEMPO Redox Mediator and Ruthenium(II) Photosensitizers with 1,2,3‐Triazole‐Derived Ligands

“…According to the tabulated photoelectrochemical properties, utilization of TEMPO + /TEMPO as redox mediator in ZnO‐based DSSCs leads to comparable properties to those using iodine‐based electrolytes (see Figure and Table S5 in the Supporting Information for the comparison). The TEMPO‐based electrolyte is favorably used in combination with RuNNN as sensitizer, which is tentatively assigned to interactions between the anionic 1,2,3‐triazolate rings and iodine, which promote recombination reactions . However, the V OC values, which may theoretically be higher for the TEMPO‐based electrolyte, are found to be lower than for the iodine‐based electrolyte owing to the enhanced recombination reactions and the lowered conduction band energy resulting from the high Li 2+ content in the electrolyte .…”

Terpyridine and Quaterpyridine Complexes as Sensitizers for Photovoltaic Applications

“…Schulze et al investigated triazolate as chelating moiety in a series of N^C^N’ cyclometalated ligands [140] and N^N’^N’’ ligands [141]. 1,3-Di(4-triazolyl)benzene and 2,5-di(4-triazolyl)pyridine were used in association with tctpy as the grafting moiety ( 42 , Figure 32).…”

4,4′-(1,2-Diazaniumylethane-1,2-diyl)dibenzoate trihydrate

“…In recent years, dyes that led to an improvement in efficiency of the current generation of dye-sensitized solar cells (DSSC) have been devised (Nazeeruddin et al, 1993;Hagfeldt et al, 2010;Brewster et al, 2013;Komatsu et al, 2013;Brown et al, 2013;Sinn et al, 2014). In our laboratory, we have been engaged in the study of chiral salen-type complexes as dyes containing carboxyl groups which can be adsorbed on the surface of TiO 2 , and with extended -conjugated system in order to improve the power generation efficiency.…”