title: Photophysics and aggregation effects of a triphenylamine-based dye sensitizer on metal-oxide nanoparticles suspended in an ion trap.
abstract: The photophysical behaviour of a triphenylamine-based organic dye sensitizer (Carbz-PAHTDTT) attached to alumina and titania nanoparticles (labelled Carbz-Al and Carbz-Ti, respectively) is examined in the absence and presence of the chenodeoxycholic acid (CDCA) coadsorber. The experiments are conducted in vacuo by suspending the target dye-sensitized nanoparticles within a quadrupole ion trap, where they are probed with laser radiation to obtain emission spectra and time-resolved excited state decay curves. For Carbz-Al, the dye's emission band is blue-shifted and the excited state lifetime is increased upon the coabsorption of CDCA, effects attributed to reduced dye aggregation. Compared to Carbz-Al, the Carbz-Ti excited state lifetimes are significantly shorter due to excited dye molecules injecting electrons into the titania conduction band. For Carbz-Ti, the electron injection quantum yields for the surfaces with CDCA (CDCA : dye = 25 : 1) and without CDCA are estimated to be 0.87 and 0.71, respectively. The gas-phase results demonstrate that Carbz-PAHTDTT dye aggregates are detrimental to the performance of a dye-sensitized solar cell.
authors.affiliation: School of Chemistry, The University of Melbourne, Victoria 3010, Australia. vdryza@unimelb.edu.au.
authors.forename: Viktoras
authors.initials: V
authors.lastname: Dryza
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Nguyen
authors.forename: Tae-Hyuk
authors.initials: TH
authors.lastname: Kwon
authors.forename: Wallace W H
authors.initials: WW
authors.lastname: Wong
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Holmes
authors.forename: Evan J
authors.initials: EJ
authors.lastname: Bieske
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D000814:Aniline Compounds / Q000737:chemistry*; D002635:Chenodeoxycholic Acid / Q000737:chemistry; D004396:Coloring Agents / Q000737:chemistry*; D005740:Gases / Q000737:chemistry; D007477:Ions / Q000737:chemistry; D007834:Lasers; D053768:Metal Nanoparticles / Q000737:chemistry*; D012993:Solar Energy; D014025:Titanium / Q000737:chemistry*
chemical_list: D000814:Aniline Compounds; D004396:Coloring Agents; D005740:Gases; D007477:Ions; D002635:Chenodeoxycholic Acid; C009495:titanium dioxide; D014025:Titanium; D000537:Aluminum Oxide