We
report the photophysical properties of the dicarboxylated diphenylisobenzofuran
dye (1) bound to nanocrystalline metal oxide surfaces.
With increased surface loading of 1, emission from the
films is significantly quenched but with a small amount of excimer
emission at maximum surface loadings. Long-lived triplets were observed
by ns TA spectroscopy that are consistent with singlet fission occurring
on mesoporous ZrO2. The evolution of these triplets, however,
could not be convincingly resolved by our subnanosecond TA spectroscopy.
Dye-sensitized devices composed of 1 on a TiO2|Al2O3 core–shell structure exhibited
an unusual decrease, increase, and then decrease in J
sc with respect to the thickness of Al2O3. In these films the Al2O3 acts as a
tunneling barrier to slow electron injection from the singlet excited
state such that singlet fission, and electron injection from the triplet
state becomes competitive. Proof-of-principle self-assembled bilayer
films that exhibit efficient triplet energy transfer from a low energy
absorbing dye to 1 is demonstrated as another step toward
a SF-based DSSC that can circumvent the Shockley–Queisser limit.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.