Research Article

Synthesis and Application of New Ruthenium Complexes Containing β-Diketonato Ligands as Sensitizers for Nanocrystalline TiO2 Solar Cells

Table 1

Absorption, luminescence, and electrochemical properties of the ruthenium complexes.

SensitizerAbsorption,  aλ max/nm ( /103 M−1 cm−1)Emission λ max  b /nmEmission τ b/nsE(Ru3+/2+)c (Ru3+/2+)d
298 K77 K298 K77 K/versus SCE/versus SCE

1294 (34.7), 329 (41.7), 440 (16.8), 615 (7.2)99093013225+0.57−0.89
2293 (22.8) 330 (19.2), 433 (9.8), 622 (4.9)99595011170+0.54−0.89
3293 (23.9), 331 (23.1), 438 (13.4), 629 (6.5)101096010150+0.53−0.88
4293 (32.0), 331 (18.7), 433 (12.2), 620 (5.5)10109608147+0.49-0.91
5293 (19.0), 332 (18.7), 435 (9.7), 630 (5.0)1010970~7130+0.46−0.92
R1 e293 (27.6), 331 (22.7), 422 (14.7), 606 (7.0)94016+0.68

aMeasured in 4 : 1 v/v ethanol:methanol at room temperature.
bThe emission spectra and emission lifetime were obtained by exciting into the lowest MLCT band in 4 : 1 v/v ethanol:methanol.
cHalf-wave potentials assigned to the Ru3+/2+ couple for ruthenium sensitizers bound to nanocrystalline TiO2 film, measured in 0.1 M LiClO4 acetonitrile solution.
dCalculated from E* (Ru3+/2+)) = E (Ru3+/2+) − E 0-0; E 0-0 values were estimated from the 5% intensity level of the emission spectra at 77 K.
eData taken from [13].