title: Investigation of plasmonic gold-silica core-shell nanoparticle stability in dye-sensitized solar cell applications.
abstract: Plasmonic core-shell Au@SiO2 nanoparticles have previously been shown to enhance the performance of dye-sensitized solar cells (DSSCs). A thin silica coating can provide a better stability during thermal processing and chemical stability to survive the corrosive electrolyte used in DSSCs. However, the thickness and completeness of the silica shell has proven crucial for the performance of the plasmonic particles and is largely controlled by the linking chemistry between the gold core and silica shell. We have evaluated four different silica coating procedures of ∼15 nm gold nanoparticles for usage in DSSCs. The chemical stability of these core-shell nanoparticles was assessed by dispersing the particles in iodide/triiodide electrolyte solution and the thermal stability by heating the particles up to 500°C. In order to maintain stable gold cores a complete silica coating was required, which was best obtained by using a mercaptosilane as a linker. In situ TEM characterization indicated that the heating process only had minor effects on the core-shell particles. The final step was to evaluate how the stable Au@SiO2 nanoparticles were influencing a real DSSC device when mixed into the TiO2 photoanode. The plasmon-incorporated DSSCs showed a ∼10% increase in efficiency compared to devices without core-shell nanoparticles.
authors.affiliation: Laboratory of Physical Chemistry and Center of Excellence for Functional Materials, Department of Natural Sciences, Åbo Akademi University, Porthansgatan 3-5, 20500 Turku, Finland.
authors.forename: Björn
authors.initials: B
authors.lastname: Törngren
authors.affiliation: Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1, Komaba, Meguro-ku, Tokyo 153-8904, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Akitsu
authors.affiliation: Physics and Center of Excellence for Functional Materials, Department of Natural Sciences, Åbo Akademi University, Porthansgatan 3-5, 20500 Turku, Finland.
authors.forename: Anne
authors.initials: A
authors.lastname: Ylinen
authors.affiliation: Physics and Center of Excellence for Functional Materials, Department of Natural Sciences, Åbo Akademi University, Porthansgatan 3-5, 20500 Turku, Finland.
authors.forename: Simon
authors.initials: S
authors.lastname: Sandén
authors.affiliation: Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, 00076 Aalto, Finland.
authors.forename: Hua
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, 00076 Aalto, Finland.
authors.forename: Janne
authors.initials: J
authors.lastname: Ruokolainen
authors.affiliation: Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1, Komaba, Meguro-ku, Tokyo 153-8904, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Komatsu
authors.affiliation: Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1, Komaba, Meguro-ku, Tokyo 153-8904, Japan.
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Hamamura
authors.affiliation: Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1, Komaba, Meguro-ku, Tokyo 153-8904, Japan.
authors.forename: Jotaro
authors.initials: J
authors.lastname: Nakazaki
authors.affiliation: Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1, Komaba, Meguro-ku, Tokyo 153-8904, Japan.
authors.forename: Takaya
authors.initials: T
authors.lastname: Kubo
authors.affiliation: Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1, Komaba, Meguro-ku, Tokyo 153-8904, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Segawa
authors.affiliation: Physics and Center of Excellence for Functional Materials, Department of Natural Sciences, Åbo Akademi University, Porthansgatan 3-5, 20500 Turku, Finland.
authors.forename: Ronald
authors.initials: R
authors.lastname: Österbacka
authors.affiliation: Laboratory of Physical Chemistry and Center of Excellence for Functional Materials, Department of Natural Sciences, Åbo Akademi University, Porthansgatan 3-5, 20500 Turku, Finland. Electronic address: jsmatt@abo.fi.
authors.forename: Jan-Henrik
authors.initials: JH
authors.lastname: Smått
keywords: Chemical stability; Core–shell; Dye-sensitized solar cell; Gold nanoparticle; Plasmon-enhancement; Thermal stability; Thin silica shell