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Endothermic and Exothermic Energy Transfer Made Equally Efficient for Triplet−Triplet Annihilation Upconversion

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Endothermic and Exothermic Energy Transfer Made Equally Efficient for Triplet−Triplet Annihilation Upconversion. / Isokuortti, Jussi; Allu, S.R.; Efimov, Alexander; Vuorimaa-Laukkanen, Elina; Tkachenko, Nikolai; Vinogradov, S.A.; Laaksonen, Timo; Durandin, Nikita.

In: Journal of Physical Chemistry Letters, Vol. 11, No. 1, 2020, p. 318−324 .

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@article{94efd50daf5041c08493e4e9513e9e7e,
title = "Endothermic and Exothermic Energy Transfer Made Equally Efficient for Triplet−Triplet Annihilation Upconversion",
abstract = "Expanding the anti-Stokes shift for triplet–triplet annihilation upconversion (TTA-UC) systems with high quantum yields without compromising power density thresholds (Ith) remains a critical challenge in photonics. Our studies reveal that such expansion is possible by using a highly endothermic TTA-UC pair with an enthalpy difference of +80 meV even in a polymer matrix 1000 times more viscous than toluene. Carrying out efficient endothermic triplet–triplet energy transfer (TET) requires suppression of the reverse annihilator-to-sensitizer TET, which was achieved by using sensitizers with high molar extinction coefficients and long triplet state lifetimes as well as optimized annihilator concentrations. Under these conditions, the sensitizer-to-annihilator forward TET becomes effectively entropy driven, yielding upconversion quantum yields comparable to those achieved with the exothermic TTA-UC pair but with larger anti-Stokes shifts and even lower Ith, a previously unattained achievement.",
author = "Jussi Isokuortti and S.R. Allu and Alexander Efimov and Elina Vuorimaa-Laukkanen and Nikolai Tkachenko and S.A. Vinogradov and Timo Laaksonen and Nikita Durandin",
year = "2020",
doi = "10.1021/acs.jpclett.9b03466",
language = "English",
volume = "11",
pages = "318−324",
journal = "Journal of Physical Chemistry Letters",
issn = "1948-7185",
publisher = "American Chemical Society",
number = "1",

}

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TY - JOUR

T1 - Endothermic and Exothermic Energy Transfer Made Equally Efficient for Triplet−Triplet Annihilation Upconversion

AU - Isokuortti, Jussi

AU - Allu, S.R.

AU - Efimov, Alexander

AU - Vuorimaa-Laukkanen, Elina

AU - Tkachenko, Nikolai

AU - Vinogradov, S.A.

AU - Laaksonen, Timo

AU - Durandin, Nikita

PY - 2020

Y1 - 2020

N2 - Expanding the anti-Stokes shift for triplet–triplet annihilation upconversion (TTA-UC) systems with high quantum yields without compromising power density thresholds (Ith) remains a critical challenge in photonics. Our studies reveal that such expansion is possible by using a highly endothermic TTA-UC pair with an enthalpy difference of +80 meV even in a polymer matrix 1000 times more viscous than toluene. Carrying out efficient endothermic triplet–triplet energy transfer (TET) requires suppression of the reverse annihilator-to-sensitizer TET, which was achieved by using sensitizers with high molar extinction coefficients and long triplet state lifetimes as well as optimized annihilator concentrations. Under these conditions, the sensitizer-to-annihilator forward TET becomes effectively entropy driven, yielding upconversion quantum yields comparable to those achieved with the exothermic TTA-UC pair but with larger anti-Stokes shifts and even lower Ith, a previously unattained achievement.

AB - Expanding the anti-Stokes shift for triplet–triplet annihilation upconversion (TTA-UC) systems with high quantum yields without compromising power density thresholds (Ith) remains a critical challenge in photonics. Our studies reveal that such expansion is possible by using a highly endothermic TTA-UC pair with an enthalpy difference of +80 meV even in a polymer matrix 1000 times more viscous than toluene. Carrying out efficient endothermic triplet–triplet energy transfer (TET) requires suppression of the reverse annihilator-to-sensitizer TET, which was achieved by using sensitizers with high molar extinction coefficients and long triplet state lifetimes as well as optimized annihilator concentrations. Under these conditions, the sensitizer-to-annihilator forward TET becomes effectively entropy driven, yielding upconversion quantum yields comparable to those achieved with the exothermic TTA-UC pair but with larger anti-Stokes shifts and even lower Ith, a previously unattained achievement.

U2 - 10.1021/acs.jpclett.9b03466

DO - 10.1021/acs.jpclett.9b03466

M3 - Article

VL - 11

SP - 318−324

JO - Journal of Physical Chemistry Letters

JF - Journal of Physical Chemistry Letters

SN - 1948-7185

IS - 1

ER -