TY - JOUR
T1 - Spin Dynamics of Quintet and Triplet States Resulting from Singlet Fission in Oriented Terrylenediimide and Quaterrylenediimide Films
AU - Bae, Youn Jue
AU - Zhao, Xingang
AU - Kryzaniak, Matthew D.
AU - Nagashima, Hiroki
AU - Strzalka, Joseph
AU - Zhang, Qingteng
AU - Wasielewski, Michael R.
N1 - Funding Information:
This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award DE-FG02-99ER14999 (M.R.W.). Y.B. gratefully acknowledges support from the Ryan Fellowship and the International Institute for Nanotechnology at Northwestern University. This work made use of the IMSERC at Northwestern University, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205), the State of Illinois, and the International Institute for Nanotechnology (IIN). GIWAXS and X-ray powder diffraction measurements were performed at Beamlines 8-ID-E and 12-ID-B with the help of Dr. Xiaobing Zuo, respectively, at the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract DE-AC02-06CH11357. Y.B. thanks Charlotte Stern, Christos D. Malliakas, and Richard S. Hong for helpful discussions regarding single crystal structure solving and the crystallographic related data analysis and Samantha Harvey for performing magnetic field dependent transient absorption spectroscopy. This work was also supported by KAKENHI JP17J01125, JP18KK0161, and JP19K15506 (H.N.).
Publisher Copyright:
© 2020 American Chemical Society.
PY - 2020/5/7
Y1 - 2020/5/7
N2 - Singlet fission in organic semiconductors provides an important opportunity to study high-spin states in electronically coupled chromophores. Photoexcitation of oriented, crystalline films of N,N-bis(pentadec-8-yl)terrylene-3,4:11,12-bis(dicarboximide) (TDI) and N,N-bis(pentadec-8-yl)quaterrylene-3,4:13,14-bis(dicarboximide) (QDI) result in the formation of the correlated triplet pair quintet state, 5(T1T1) and its subsequent dissociation into two triplet (T1) excitons. Time-resolved electron paramagnetic resonance (TREPR) spectroscopy and X-ray crystallography are used to show that the orientation dependence of 5(T1T1) spin dynamics is retained as it dissociates into two T1 excitons, while such information is lost in a randomly oriented sample. In addition, the spin dynamics depend on how the molecules are oriented relative to the external applied magnetic field. Dissociation of 5(T1T1) to form two T1 excitons is more efficient in TDI and leads to a longer T1 lifetime than in QDI, making TDI a more viable candidate for photovoltaic applications. Since QDI readily forms a highly oriented film, and the lifetime of its 5(T1T1) state is longer than that of TDI, it may be a good candidate for quantum information science applications that require the generation of a quantum-entangled, four-spin state.
AB - Singlet fission in organic semiconductors provides an important opportunity to study high-spin states in electronically coupled chromophores. Photoexcitation of oriented, crystalline films of N,N-bis(pentadec-8-yl)terrylene-3,4:11,12-bis(dicarboximide) (TDI) and N,N-bis(pentadec-8-yl)quaterrylene-3,4:13,14-bis(dicarboximide) (QDI) result in the formation of the correlated triplet pair quintet state, 5(T1T1) and its subsequent dissociation into two triplet (T1) excitons. Time-resolved electron paramagnetic resonance (TREPR) spectroscopy and X-ray crystallography are used to show that the orientation dependence of 5(T1T1) spin dynamics is retained as it dissociates into two T1 excitons, while such information is lost in a randomly oriented sample. In addition, the spin dynamics depend on how the molecules are oriented relative to the external applied magnetic field. Dissociation of 5(T1T1) to form two T1 excitons is more efficient in TDI and leads to a longer T1 lifetime than in QDI, making TDI a more viable candidate for photovoltaic applications. Since QDI readily forms a highly oriented film, and the lifetime of its 5(T1T1) state is longer than that of TDI, it may be a good candidate for quantum information science applications that require the generation of a quantum-entangled, four-spin state.
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U2 - 10.1021/acs.jpcc.0c03189
DO - 10.1021/acs.jpcc.0c03189
M3 - Article
AN - SCOPUS:85085138005
VL - 124
SP - 9822
EP - 9833
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 18
ER -
