Development of thiocyanate-free, charge-neutral Ru(II) sensitizers for dye-sensitized solar cells

A new series of neutral, thiocyanate-free Ru(II) sensitizers (TFRS-1-3), which are assembled using both 4,4'-carboxy2,2'-bypyridine and 2-pyridyl pyrazolate ancillaries, exhibit a light-harvesting capability up to 700 nm and superior DSSC performance in conversion efficiency (n = 9.54% for TFRS-2).