TY - JOUR
T1 - Femtosecond Raman Microscopy Reveals Structural Dynamics Leading to Triplet Separation in Rubrene Singlet Fission
AU - Bera, Kajari
AU - Douglas, Christopher J
AU - Frontiera, Renee R
N1 - Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/12/7
Y1 - 2017/12/7
N2 - Singlet fission generates multiple excitons from a single photon, which in theory can result in solar cell efficiencies with values above the Shockley-Queisser limit. Understanding the molecular structural dynamics during singlet fission will help to fabricate efficient organic photovoltaic devices. Here we use femtosecond stimulated Raman spectroscopy to reveal the structural evolution during the triplet separation in rubrene. We observe vibrational signatures of the correlated triplet pair, as well as shifting of the vibrational frequencies of the 1430 and 1542 cm-1 excited state modes, which increase by more than 25 cm-1 in 5 ps. Our results indicate that the correlated pair separation into two individual triplets occurs concurrently with the loss of electron density from the tetracene backbone in rubrene. This study provides new insights into the triplet separation process and proves the utility of structurally sensitive ultrafast vibrational techniques to understand the mechanism of singlet fission.
AB - Singlet fission generates multiple excitons from a single photon, which in theory can result in solar cell efficiencies with values above the Shockley-Queisser limit. Understanding the molecular structural dynamics during singlet fission will help to fabricate efficient organic photovoltaic devices. Here we use femtosecond stimulated Raman spectroscopy to reveal the structural evolution during the triplet separation in rubrene. We observe vibrational signatures of the correlated triplet pair, as well as shifting of the vibrational frequencies of the 1430 and 1542 cm-1 excited state modes, which increase by more than 25 cm-1 in 5 ps. Our results indicate that the correlated pair separation into two individual triplets occurs concurrently with the loss of electron density from the tetracene backbone in rubrene. This study provides new insights into the triplet separation process and proves the utility of structurally sensitive ultrafast vibrational techniques to understand the mechanism of singlet fission.
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U2 - 10.1021/acs.jpclett.7b02769
DO - 10.1021/acs.jpclett.7b02769
M3 - Article
C2 - 29166019
AN - SCOPUS:85037709198
SN - 1948-7185
VL - 8
SP - 5929
EP - 5934
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
IS - 23
ER -