Ultrafast Triplet Pair Separation and Triplet Trapping following Singlet Fission in Amorphous Pentacene Films

Kyle T. Munson; Jianing Gan; Christopher Grieco; Grayson S. Doucette; John E. Anthony; John B. Asbury

doi:10.1021/acs.jpcc.0c07920

Ultrafast Triplet Pair Separation and Triplet Trapping following Singlet Fission in Amorphous Pentacene Films

Kyle T. Munson, Jianing Gan, Christopher Grieco, Grayson S. Doucette, John E. Anthony, John B. Asbury

Chemistry

Research output: Contribution to journal › Article › peer-review

9 Scopus citations

Abstract

Ultrafast infrared and electronic spectroscopy are used to examine the dynamics of triplet pair separation following singlet fission in amorphous and crystalline films of the model singlet fission chromophore, 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-Pn). Probing of correlated triplet pair intermediates directly through their unique vibrational frequencies and infrared electronic transitions and indirectly through their visible triplet absorptions reveals that triplet pair separation occurs on similar picosecond time scales in both amorphous and crystalline films despite their markedly different average intermolecular coupling strengths. Although triplet pair separation occurs on similar time scales in both environments, measurements of diffusion-controlled triplet-triplet annihilation reveal that the diffusivity of triplet excited states is an order of magnitude lower in amorphous films. The data reveal the presence of sparse triplet traps in the amorphous environment that inhibit the transport of triplet excitons in comparison to crystalline films. These observations inform recent efforts to develop disordered and polymeric singlet fission sensitizers that contain amorphous regions. In particular, the data suggest that it may be possible to nanostructure amorphous or polymeric singlet fission sensitizers to allow ultrafast triplet pair separation and harvesting in photovoltaic and light-emitting applications despite their low triplet exciton diffusivity.

Original language	English
Pages (from-to)	23567-23578
Number of pages	12
Journal	Journal of Physical Chemistry C
Volume	124
Issue number	43
DOIs	https://doi.org/10.1021/acs.jpcc.0c07920
State	Published - Oct 29 2020

Bibliographical note

Funding Information:
J.G., C.G., G.S.D., and J.B.A. thank the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences for support of this research through Grant DE-SC0019349. K.T.M. is grateful for support from the National Science Foundation Graduate Research Fellowship Program under Grant DGE-1255832. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Organic semiconductor synthesis (J.E.A.) was supported by the National Science Foundation under Cooperative Agreement No. 1849213.

Funding Information:
J.G., C.G., G.S.D., and J.B.A. thank the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences for support of this research through Grant DE-SC0019349. K.T.M. is grateful for support from the National Science Foundation Graduate Research Fellowship Program under Grant DGE-1255832. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Organic semiconductor synthesis (J.E.A.) was supported by the National Science Foundation under Cooperative Agreement No. 1849213.

Publisher Copyright:
© 2020 American Chemical Society.

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Energy (all)
Physical and Theoretical Chemistry
Surfaces, Coatings and Films

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1021/acs.jpcc.0c07920

Cite this

@article{7a21f1d3e0d640f0a0694de69e7733e3,

title = "Ultrafast Triplet Pair Separation and Triplet Trapping following Singlet Fission in Amorphous Pentacene Films",

abstract = "Ultrafast infrared and electronic spectroscopy are used to examine the dynamics of triplet pair separation following singlet fission in amorphous and crystalline films of the model singlet fission chromophore, 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-Pn). Probing of correlated triplet pair intermediates directly through their unique vibrational frequencies and infrared electronic transitions and indirectly through their visible triplet absorptions reveals that triplet pair separation occurs on similar picosecond time scales in both amorphous and crystalline films despite their markedly different average intermolecular coupling strengths. Although triplet pair separation occurs on similar time scales in both environments, measurements of diffusion-controlled triplet-triplet annihilation reveal that the diffusivity of triplet excited states is an order of magnitude lower in amorphous films. The data reveal the presence of sparse triplet traps in the amorphous environment that inhibit the transport of triplet excitons in comparison to crystalline films. These observations inform recent efforts to develop disordered and polymeric singlet fission sensitizers that contain amorphous regions. In particular, the data suggest that it may be possible to nanostructure amorphous or polymeric singlet fission sensitizers to allow ultrafast triplet pair separation and harvesting in photovoltaic and light-emitting applications despite their low triplet exciton diffusivity. ",

author = "Munson, {Kyle T.} and Jianing Gan and Christopher Grieco and Doucette, {Grayson S.} and Anthony, {John E.} and Asbury, {John B.}",

note = "Funding Information: J.G., C.G., G.S.D., and J.B.A. thank the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences for support of this research through Grant DE-SC0019349. K.T.M. is grateful for support from the National Science Foundation Graduate Research Fellowship Program under Grant DGE-1255832. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Organic semiconductor synthesis (J.E.A.) was supported by the National Science Foundation under Cooperative Agreement No. 1849213. Funding Information: J.G., C.G., G.S.D., and J.B.A. thank the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences for support of this research through Grant DE-SC0019349. K.T.M. is grateful for support from the National Science Foundation Graduate Research Fellowship Program under Grant DGE-1255832. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Organic semiconductor synthesis (J.E.A.) was supported by the National Science Foundation under Cooperative Agreement No. 1849213. Publisher Copyright: {\textcopyright} 2020 American Chemical Society.",

year = "2020",

month = oct,

day = "29",

doi = "10.1021/acs.jpcc.0c07920",

language = "English",

volume = "124",

pages = "23567--23578",

number = "43",

}

TY - JOUR

T1 - Ultrafast Triplet Pair Separation and Triplet Trapping following Singlet Fission in Amorphous Pentacene Films

AU - Munson, Kyle T.

AU - Gan, Jianing

AU - Grieco, Christopher

AU - Doucette, Grayson S.

AU - Anthony, John E.

AU - Asbury, John B.

N1 - Funding Information: J.G., C.G., G.S.D., and J.B.A. thank the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences for support of this research through Grant DE-SC0019349. K.T.M. is grateful for support from the National Science Foundation Graduate Research Fellowship Program under Grant DGE-1255832. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Organic semiconductor synthesis (J.E.A.) was supported by the National Science Foundation under Cooperative Agreement No. 1849213. Funding Information: J.G., C.G., G.S.D., and J.B.A. thank the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences for support of this research through Grant DE-SC0019349. K.T.M. is grateful for support from the National Science Foundation Graduate Research Fellowship Program under Grant DGE-1255832. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Organic semiconductor synthesis (J.E.A.) was supported by the National Science Foundation under Cooperative Agreement No. 1849213. Publisher Copyright: © 2020 American Chemical Society.

PY - 2020/10/29

Y1 - 2020/10/29

N2 - Ultrafast infrared and electronic spectroscopy are used to examine the dynamics of triplet pair separation following singlet fission in amorphous and crystalline films of the model singlet fission chromophore, 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-Pn). Probing of correlated triplet pair intermediates directly through their unique vibrational frequencies and infrared electronic transitions and indirectly through their visible triplet absorptions reveals that triplet pair separation occurs on similar picosecond time scales in both amorphous and crystalline films despite their markedly different average intermolecular coupling strengths. Although triplet pair separation occurs on similar time scales in both environments, measurements of diffusion-controlled triplet-triplet annihilation reveal that the diffusivity of triplet excited states is an order of magnitude lower in amorphous films. The data reveal the presence of sparse triplet traps in the amorphous environment that inhibit the transport of triplet excitons in comparison to crystalline films. These observations inform recent efforts to develop disordered and polymeric singlet fission sensitizers that contain amorphous regions. In particular, the data suggest that it may be possible to nanostructure amorphous or polymeric singlet fission sensitizers to allow ultrafast triplet pair separation and harvesting in photovoltaic and light-emitting applications despite their low triplet exciton diffusivity.

AB - Ultrafast infrared and electronic spectroscopy are used to examine the dynamics of triplet pair separation following singlet fission in amorphous and crystalline films of the model singlet fission chromophore, 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-Pn). Probing of correlated triplet pair intermediates directly through their unique vibrational frequencies and infrared electronic transitions and indirectly through their visible triplet absorptions reveals that triplet pair separation occurs on similar picosecond time scales in both amorphous and crystalline films despite their markedly different average intermolecular coupling strengths. Although triplet pair separation occurs on similar time scales in both environments, measurements of diffusion-controlled triplet-triplet annihilation reveal that the diffusivity of triplet excited states is an order of magnitude lower in amorphous films. The data reveal the presence of sparse triplet traps in the amorphous environment that inhibit the transport of triplet excitons in comparison to crystalline films. These observations inform recent efforts to develop disordered and polymeric singlet fission sensitizers that contain amorphous regions. In particular, the data suggest that it may be possible to nanostructure amorphous or polymeric singlet fission sensitizers to allow ultrafast triplet pair separation and harvesting in photovoltaic and light-emitting applications despite their low triplet exciton diffusivity.

UR - http://www.scopus.com/inward/record.url?scp=85096046219&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85096046219&partnerID=8YFLogxK

U2 - 10.1021/acs.jpcc.0c07920

DO - 10.1021/acs.jpcc.0c07920

M3 - Article

AN - SCOPUS:85096046219

VL - 124

SP - 23567

EP - 23578

IS - 43

ER -

Ultrafast Triplet Pair Separation and Triplet Trapping following Singlet Fission in Amorphous Pentacene Films

Abstract

Bibliographical note

ASJC Scopus subject areas

UN SDGs

Access to Document

Other files and links

Fingerprint

Cite this