title: Photoinduced charge separation reactions of J-aggregates coated on silver nanoparticles.
abstract: The photochemistry of cyanine J-aggregates on the surface of colloidal Ag nanoparticles is reported. The photochemistry is initiated through ultrafast photoexcitation of the plasmon band in Ag nanoparticles, producing an enhanced near-field that interacts with the J-aggregate monolayer. Through transient absorption spectroscopy, we show that photoexcitation of the plasmon in Ag nanoparticles leads to exciton dynamics that differ strongly from J-aggregates alone or for J-aggregate monolayers on bulk metal surfaces. Specifically, charge-separated states with a lifetime of approximately 300 ps between the J-aggregate and Ag colloid are formed. The reduction of the Ag nanoparticles is shown to be a multielectron process.
authors.affiliation: Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439-4831, USA.
authors.forename: Jasmina
authors.initials: J
authors.lastname: Hranisavljevic
authors.forename: Nada M
authors.initials: NM
authors.lastname: Dimitrijevic
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Wurtz
authors.forename: Gary P
authors.initials: GP
authors.lastname: Wiederrecht