High Molar Extinction Coefficient Ru(II)-Mixed Ligand Polypyridyl Complexes for Dye Sensitized Solar Cell Application

Two new ruthenium(II) mixed ligand terpyridine complexes, "Ru(Htcterpy)(NCS)(L1) (N(C4H9)(4)), mLBD1" and Ru(Htcterpy) (NCS)(L2)(N(C4H9)(4)), mLBD2 were synthesized and fully characterized by UV-Vis, emission, cyclic voltammogram, and other spectroscopic means, and the structures of the compounds are confirmed by H-1-NMR, ESI-MASS, and FT-IR spectroscopes. The influence of the substitution of L1 and L2 on solar-to-electrical energy conversion efficiency (eta) of dye-sensitized solar cells (DSSCs) was evaluated relative to reference black dye. The dyes showed molar extinction coefficients of 17600 M-1 cm(-1) for mLBD1 and 21300 M-1 cm(-1) for mLBD2 both at lambda maximum of 512 nm, while black dye has shown 8660 M-1 cm(-1) at lambda maximum of 615 nm. The monochromatic incident photon-to-collected electron conversion efficiencies of 60.71% and 75.89% were obtained for mLBD1 and mLBD2 dyes, respectively. The energy conversion efficiencies of mLBD1 and mLBD2 dyes are 3.15% (J(SC) = 11.86 mA/cm(2), V-OC = 613 mV, ff = 0.4337) and 3.36% (J(SC) = 12.71 mA/cm(2), V-OC = 655 mV, ff = 0.4042), respectively, measured at the AM1.5G conditions, the reference black dye-sensitized solar cell, fabricated and evaluated under identical conditions exhibited eta-value of 2.69% (J(SC) = 10.95 mA/cm(2), V-OC = 655 mV, ff = 0.3750).