Dynamics of singlet fission and electron injection in self-assembled acene monolayers on titanium dioxide.

ABSTRACT: We employ a combination of linear spectroscopy, electrochemistry, and transient absorption spectroscopy to characterize the interplay between electron transfer and singlet fission dynamics in polyacene-based dyes attached to nanostructured TiO₂. For triisopropyl silylethynyl (TIPS)-pentacene, we find that the singlet fission time constant increases to 6.5 ps on a nanostructured TiO₂ surface relative to a thin film time constant of 150 fs, and that triplets do not dissociate after they are formed. In contrast, TIPS-tetracene singlets quickly dissociate in 2 ps at the molecule/TiO₂ interface, and this dissociation outcompetes the relatively slow singlet fission process. The addition of an alumina layer slows down electron injection, allowing the formation of

SUBMITTER: Pace NA 

PROVIDER: S-EPMC5915837 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature