A study of electron transfer in Ru(dcbpy)2(NCS)2 sensitized nanocrystalline TiO2 and SnO2 films induced by red-wing excitation.
Excited state dynamics and electron transfer from the Ru(dcbpy)2(NCS)2 (RuN3) sensitizer to semiconductor nanoparticles were studied using time-resolved femtosecond absorption spectroscopy. We found that excitation of the red wing of the absorption spectrum of the sensitizer populates the (3)MLCT state directly, both in solution and attached on semiconductor nanoparticle films. Electron injection is slowed down and becomes gradually less efficient as excitation moves towards red from the absorption maximum at 535 nm. At 675 nm the injection is non-exponential and characterized by 5, 30 and 180 ps time constants. The non-exponential electron injection observed is assigned to injection from a distribution of triplet states with energies below the semiconductor conduction band edge.
Myllyperkiö
Pasi
P
Department of Chemistry, Nanoscience Center, P.O. Box: 35, FI-40014 University of Jyväskylä, Finland. pasi.myllyperkio@jyu.fi
Benko
Gábor
G
Korppi-Tommola
Jouko
J
Yartsev
Arkady P
AP
Sundström
Villy
V
D004396:Coloring Agents / Q000737:chemistry; D004583:Electrons; D007700:Kinetics; D007834:Lasers; D008567:Membranes, Artificial; D049329:Nanostructures / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D010777:Photochemistry; D012428:Ruthenium / Q000737:chemistry*; D012666:Semiconductors; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis / Q000379:methods; D013499:Surface Properties; D013861:Thiocyanates / Q000737:chemistry*; D013997:Time Factors; D017971:Tin Compounds / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
D004396:Coloring Agents; D008567:Membranes, Artificial; D009942:Organometallic Compounds; D013861:Thiocyanates; D017971:Tin Compounds; C009495:titanium dioxide; D012428:Ruthenium; D014025:Titanium; C045358:stannic oxide