title: A study of electron transfer in Ru(dcbpy)2(NCS)2 sensitized nanocrystalline TiO2 and SnO2 films induced by red-wing excitation.
abstract: 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.
authors.affiliation: Department of Chemistry, Nanoscience Center, P.O. Box: 35, FI-40014 University of Jyväskylä, Finland. pasi.myllyperkio@jyu.fi
authors.forename: Pasi
authors.initials: P
authors.lastname: Myllyperkiö
authors.forename: Gábor
authors.initials: G
authors.lastname: Benko
authors.forename: Jouko
authors.initials: J
authors.lastname: Korppi-Tommola
authors.forename: Arkady P
authors.initials: AP
authors.lastname: Yartsev
authors.forename: Villy
authors.initials: V
authors.lastname: Sundström
mesh_terms: 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*
chemical_list: D004396:Coloring Agents; D008567:Membranes, Artificial; D009942:Organometallic Compounds; D013861:Thiocyanates; D017971:Tin Compounds; C009495:titanium dioxide; D012428:Ruthenium; D014025:Titanium; C045358:stannic oxide