Electron transfer from the singlet and triplet excited states of Ru(dcbpy)(2)(NCS)(2) into nanocrystalline TiO2 thin films

Research output: Contribution to journalArticle

Abstract

Time-resolved absorption spectroscopy was used to study the femtosecond and picosecond time scale electron injection from the excited singlet and triplet states of Ru(dcbpY)(2)(NCS)(2) (RuN3) into titanium dioxide (TiO2) nanocrystalline particle film in acetonitrile. The fastest resolved time constant of similar to30 fs was shown to reflect a sum of two parallel ultrafast processes, nonergodic electron transfer (ET) from the initially excited singlet state of RuN3 to the conduction band of TiO2 and intersystem crossing (ISC). The branching ratio of 1.5 between the two competing processes gives rate constants of 1/50 fs(-1) for ET and 1/75 fs(-1) for ISC. Following the ultrafast processes, a minor part of the electron injection (40%) occurs from the thermalized triplet state of RuN3 on the picosecond time scale. The kinetics of this slower phase of electron injection is nonexponential and can be fitted with time constants ranging from similar to1 to similar to60 ps.

Details

Authors
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Atom and Molecular Physics and Optics
Original languageEnglish
Pages (from-to)4396-4404
JournalThe Journal of Physical Chemistry Part B
Volume106
Issue number17
Publication statusPublished - 2002
Publication categoryResearch
Peer-reviewedYes

Bibliographic note

The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Chemical Physics (S) (011001060)