Abstract
Ultrafast vibrational spectroscopy in the mid-infrared spectral range provides the opportunity to probe the dynamics of electronic states involved in all stages of the singlet fission reaction through their unique vibrational frequencies. This capability is demonstrated using a model singlet fission chromophore, 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-Pn). The alkyne groups of the TIPS side chains are coupled to the conjugated framework of the pentacene cores, enabling direct examination of the dynamics of triplet excitons that have successfully separated from correlated triplet pair states in crystalline films of TIPS-Pn. Relaxation processes during the separation of triplet excitons and triplet-triplet annihilation after their separation result in the formation of hot ground state molecules that also exhibit unique vibrational frequencies. Because all organic molecules possess native vibrational modes, ultrafast vibrational spectroscopy offers a new approach to examine the dynamics of electronic intermediates that may inform ongoing efforts to utilize singlet fission to overcome thermalization losses in photovoltaic applications.
Original language | English |
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Pages (from-to) | 5700-5706 |
Number of pages | 7 |
Journal | Journal of Physical Chemistry Letters |
Volume | 8 |
Issue number | 23 |
DOIs | |
State | Published - Dec 7 2017 |
Bibliographical note
Funding Information:C.G., E.R.K., A.R., and J.B.A. thank the Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences of the U.S. Department of Energy through Grant DE-SC0008120 for support of this research. J.E.A. and M.M.P. thank the National Science Foundation (CMMI-1255494) for support of organic semiconductor synthesis.
Funding Information:
C.G., E.R.K., A.R., and J.B.A. thank the Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences of the U.S. Department of Energy through Grant DESC0008120 for support of this research. J.E.A. and M.M.P. thank the National Science Foundation (CMMI-1255494) for support of organic semiconductor synthesis.
Publisher Copyright:
© 2017 American Chemical Society.
ASJC Scopus subject areas
- Materials Science (all)
- Physical and Theoretical Chemistry