Vibronic exciton theory of singlet fission. I. Linear absorption and the anatomy of the correlated triplet pair state

Roel Tempelaar, David R. Reichman

Research output: Contribution to journalArticlepeer-review

55 Scopus citations

Abstract

Recent time-resolved spectroscopic experiments have indicated that vibronic coupling plays a vital role in facilitating the process of singlet fission. In this work, which forms the first article of a series, we set out to unravel the mechanisms underlying singlet fission through a vibronic exciton theory. We formulate a model in which both electronic and vibrational degrees of freedom are treated microscopically and non-perturbatively. Using pentacene as a prototypical material for singlet fission, we subject our theory to comparison with measurements on polarization-resolved absorption of single crystals, and employ our model to characterize the excited states underlying the absorption band. Special attention is given to the convergence of photophysical observables with respect to the basis size employed, through which we determine the optimal basis for more expensive calculations to be presented in subsequent work. We furthermore evaluate the energetic separation between the optically prepared singlet excited state and the correlated triplet pair state, as well as provide a real-space characterization of the latter, both of which are of key importance in the discussion of fission dynamics. We discuss our results in the context of recent experimental studies.

Original languageEnglish (US)
Article number174703
JournalJournal of Chemical Physics
Volume146
Issue number17
DOIs
StatePublished - May 7 2017

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'Vibronic exciton theory of singlet fission. I. Linear absorption and the anatomy of the correlated triplet pair state'. Together they form a unique fingerprint.

Cite this