1 research outputs found
In Situ Mapping of the Molecular Arrangement of Amphiphilic Dye Molecules at the TiO<sub>2</sub> Surface of Dye-Sensitized Solar Cells
Amphiphilic
sensitizers are central to the function of dye-sensitized solar cells.
It is known that the cell’s performance depends on the molecular
arrangement and the density of the dye on the semiconductor surface,
but a molecular-level picture of the cell–electrolyte interface
is still lacking. Here, we present subnanometer in situ atomic force
microscopy images of the Z907 dye at the surface of TiO<sub>2</sub> in a relevant liquid. Our results reveal changes in the conformation
and the lateral arrangement of the dye molecules, depending on their
average packing density on the surface. Complementary quantitative
measurements on the ensemble of the film are obtained by the quartz-crystal
microbalance with dissipation technique. An atomistic picture of the
dye coverage-dependent packing, the effectiveness of the hydrophobic
alkyl chains as blocking layer, and the solvent accessibility is obtained
from molecular dynamics simulations