title: Geometrical and energetical structural changes in organic dyes for dye-sensitized solar cells probed using photoelectron spectroscopy and DFT.
abstract: The effects of alkoxy chain length in triarylamine based donor-acceptor organic dyes are investigated with respect to the electronic and molecular surface structures on the performance of solar cells and the electron lifetime. The dyes were investigated when adsorbed on TiO2 in a configuration that can be used for dye-sensitized solar cells (DSCs). Specifically, the two dyes D35 and D45 were compared using photoelectron spectroscopy (PES) and density functional theory (DFT) calculations. The differences in solar cell characteristics when longer alkoxy chains are introduced in the dye donor unit are attributed to geometrical changes in dye packing while only minor differences were observed in the electronic structure. A higher dye load was observed for D45 on TiO2. However, D35 based solar cells result in higher photocurrent although the dye load is lower. This is explained by different geometrical structures of the dyes on the surface.
authors.affiliation: Department of Chemistry-Ångström, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden.
authors.forename: Susanna K
authors.initials: SK
authors.lastname: Eriksson
authors.forename: Ida
authors.initials: I
authors.lastname: Josefsson
authors.forename: Hanna
authors.initials: H
authors.lastname: Ellis
authors.forename: Anna
authors.initials: A
authors.lastname: Amat
authors.forename: Mariachiara
authors.initials: M
authors.lastname: Pastore
authors.forename: Johan
authors.initials: J
authors.lastname: Oscarsson
authors.forename: Rebecka
authors.initials: R
authors.lastname: Lindblad
authors.forename: Anna I K
authors.initials: AI
authors.lastname: Eriksson
authors.forename: Erik M J
authors.initials: EM
authors.lastname: Johansson
authors.forename: Gerrit
authors.initials: G
authors.lastname: Boschloo
authors.forename: Anders
authors.initials: A
authors.lastname: Hagfeldt
authors.forename: Simona
authors.initials: S
authors.lastname: Fantacci
authors.forename: Michael
authors.initials: M
authors.lastname: Odelius
authors.forename: Håkan
authors.initials: H
authors.lastname: Rensmo