Highly Efficient Dye-Sensitized Solar Cells Based on Panchromatic Ruthenium Sensitizers with Quinolinylbipyridine Anchors

Panchromatic Ru^II sensitizers TF-30-TF-33 bearing a new class of 6-quinolin-8-yl-2,2′-bipyridine anchor were synthesized and tested under AM1.5 G simulated solar irradiation. Their increased π conjugation relative to that of the traditional 2,2′:6′,2′′-terpyridine-based anchor led to a remarkable improvement in absorptivity across the whole UV-Vis-NIR spectral regime. Furthermore, the introduction of a bulky tert-butyl substituent on the quinolinyl fragment not only led to an increase in the J_SC value owing to the suppression of dye aggregation, but remarkably also resulted in no loss in V_OC in comparison with the reference sensitizer containing a tricarboxyterpyridine anchor. The champion sensitizer in DSC devices was found to be TF-32 with a performance of J_SC=19.2 mA cm^-2, V_OC=740 mV, FF=0.72, and η=10.19 %. This 6-quinolin-8-yl-2,2′-bipyridine anchor thus serves as a prototype for the next generation of Ru^II sensitizers with any tridentate ancillary.