title: Know thy nano neighbor. Plasmonic versus electron charging effects of metal nanoparticles in dye-sensitized solar cells.
abstract: Neighboring metal nanoparticles influence photovoltaic and photocatalytic behavior of semiconductor nanostructures either through Fermi level equilibration by accepting electrons or inducing localized surface plasmon effects. By employing SiO(2)- and TiO(2)-capped Au nanoparticles we have identified the mechanism with which the performance of dye-sensitized solar cells (DSSC) is influenced by the neighboring metal nanoparticles. The efficiency of an N719 dye-sensitized solar cell (9.3%) increased to 10.2% upon incorporation of 0.7% Au@SiO(2) and to 9.8% upon loading of 0.7% Au@TiO(2) nanoparticles. The plasmonic effect as monitored by introducing Au@SiO(2) in DSSC produces higher photocurrent. However, Au nanoparticles undergo charge equilibration with TiO(2) nanoparticles and shift the apparent Fermi level of the composite to more negative potentials. As a result, Au@TiO(2) nanoparticle-embedded DSSC exhibit higher photovoltage. A better understanding of these two effects is crucial in exploiting the beneficial aspects of metal nanoparticles in photovoltaics.
authors.affiliation: Radiation Laboratory, Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors.forename: Hyunbong
authors.initials: H
authors.lastname: Choi
authors.forename: Wei Ta
authors.initials: WT
authors.lastname: Chen
authors.forename: Prashant V
authors.initials: PV
authors.lastname: Kamat
mesh_terms: D004396:Coloring Agents; D053768:Metal Nanoparticles; D046529:Microscopy, Electron, Transmission; D013472:Sunlight
chemical_list: D004396:Coloring Agents