An insight into non-emissive excited states in conjugated polymers

doi:10.1038/ncomms9246

Title: An insight into non-emissive excited states in conjugated polymers

Abstract

Conjugated polymers in the solid state usually exhibit low fluorescence quantum yields, which limit their applications in many areas such as light-emitting diodes. Despite considerable research efforts, the underlying mechanism still remains controversial and elusive. Here, the nature and properties of excited states in the archetypal polythiophene are investigated via aggregates suspended in solvents with different dielectric constants (ε). In relatively polar solvents (ε>~ 3), the aggregates exhibit a low fluorescence quantum yield (QY) of 2–5%, similar to bulk films, however, in relatively nonpolar solvents (ε<~ 3) they demonstrate much higher fluorescence QY up to 20–30%. A series of mixed quantum-classical atomistic simulations illustrate that dielectric induced stabilization of nonradiative charge-transfer (CT) type states can lead to similar drastic reduction in fluorescence QY as seen experimentally. In conclusion, fluorescence lifetime measurement reveals that the CT-type states exist as a competitive channel of the formation of emissive exciton-type states.

Authors:

Hu, Zhongjian ^[1]; Willard, Adam P. ^[1]; Ono, Robert J. ^[1]; Bielawski, Christopher W. ^[1]; Rossky, Peter J. ^[1];

^[1]

Univ. of Texas at Austin, Austin, TX (United States)

Publication Date:: 2015-09-22

Research Org.:: Energy Frontier Research Centers (EFRC) (United States). Understanding Charge Separation and Transfer at Interfaces in Energy Materials (CST); Univ. of Texas at Austin, Austin, TX (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)

OSTI Identifier:: 1459344

Grant/Contract Number:: SC0001091

Resource Type:: Accepted Manuscript

Journal Name:: Nature Communications

Additional Journal Information:: Journal Volume: 6; Journal Issue: 1; Journal ID: ISSN 2041-1723

Publisher:: Nature Publishing Group

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE

Citation Formats


                    Hu, Zhongjian, Willard, Adam P., Ono, Robert J., Bielawski, Christopher W., Rossky, Peter J., and Vanden Bout, David A. An insight into non-emissive excited states in conjugated polymers.  United States: N. p., 2015. 
        Web.  doi:10.1038/ncomms9246.

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                    Hu, Zhongjian, Willard, Adam P., Ono, Robert J., Bielawski, Christopher W., Rossky, Peter J., & Vanden Bout, David A. An insight into non-emissive excited states in conjugated polymers.  United States.  doi:10.1038/ncomms9246.

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                    Hu, Zhongjian, Willard, Adam P., Ono, Robert J., Bielawski, Christopher W., Rossky, Peter J., and Vanden Bout, David A. Tue .  
        "An insight into non-emissive excited states in conjugated polymers".  United States.  doi:10.1038/ncomms9246.  https://www.osti.gov/servlets/purl/1459344.

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@article{osti_1459344,

  title        = {An insight into non-emissive excited states in conjugated polymers},

  author       = {Hu, Zhongjian and Willard, Adam P. and Ono, Robert J. and Bielawski, Christopher W. and Rossky, Peter J. and Vanden Bout, David A.},

  abstractNote = {Conjugated polymers in the solid state usually exhibit low fluorescence quantum yields, which limit their applications in many areas such as light-emitting diodes. Despite considerable research efforts, the underlying mechanism still remains controversial and elusive. Here, the nature and properties of excited states in the archetypal polythiophene are investigated via aggregates suspended in solvents with different dielectric constants (ε). In relatively polar solvents (ε>~ 3), the aggregates exhibit a low fluorescence quantum yield (QY) of 2–5%, similar to bulk films, however, in relatively nonpolar solvents (ε<~ 3) they demonstrate much higher fluorescence QY up to 20–30%. A series of mixed quantum-classical atomistic simulations illustrate that dielectric induced stabilization of nonradiative charge-transfer (CT) type states can lead to similar drastic reduction in fluorescence QY as seen experimentally. In conclusion, fluorescence lifetime measurement reveals that the CT-type states exist as a competitive channel of the formation of emissive exciton-type states.},

  doi          = {10.1038/ncomms9246},

  journal      = {Nature Communications},

  number       = 1,

  volume       = 6,

  place        = {United States},

  year         = {2015},

  month        = {9}

}

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DOI: 10.1038/ncomms9246

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Works referenced in this record:

Synthesis, Properties, and Electronic Applications of Size-Controlled Poly(3-hexylthiophene) Nanoparticles
journal, August 2010

Millstone, Jill E.; Kavulak, David F. J.; Woo, Claire H.
Langmuir, Vol. 26, Issue 16, p. 13056-13061
DOI: 10.1021/la1022938

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Title: An insight into non-emissive excited states in conjugated polymers

Abstract

Citation Formats

Synthesis, Properties, and Electronic Applications of Size-Controlled Poly(3-hexylthiophene) Nanoparticles journal, August 2010

Synthesis, Properties, and Electronic Applications of Size-Controlled Poly(3-hexylthiophene) Nanoparticles
journal, August 2010