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Photophysical Exploration of Rigidly Coupled Dimers for Singlet Fission and Triplet-Triplet Annihilation Upconversion.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Photophysical Exploration of Rigidly Coupled Dimers for Singlet Fission and Triplet-Triplet Annihilation Upconversion./
Author:	Gilligan, Alexander Thomas.
Description:	1 online resource (233 pages)
Notes:	Source: Dissertations Abstracts International, Volume: 84-11, Section: B.
Contained By:	Dissertations Abstracts International84-11B.
Subject:	Physical chemistry. -
Online resource:	click for full text (PQDT)
ISBN:	9798379527815

Photophysical Exploration of Rigidly Coupled Dimers for Singlet Fission and Triplet-Triplet Annihilation Upconversion.
Gilligan, Alexander Thomas.

Photophysical Exploration of Rigidly Coupled Dimers for Singlet Fission and Triplet-Triplet Annihilation Upconversion. - 1 online resource (233 pages)

Source: Dissertations Abstracts International, Volume: 84-11, Section: B.

Thesis (Ph.D.)--University of Colorado at Boulder, 2023.

Includes bibliographical references

The Sun is a nearly unlimited source of energy that can be used on Earth to power society without substantial impact to the broader environment that humanity depends on. Decades of work by the scientific community have gone into understanding the science of solar energy and engineering it for useful application. Fundamental limits prevent taking full advantage of available solar energy. Exciton downconversion/upconversion in organic systems, also known as singlet fission (SF) and triplet-triplet annihilation (TTA), are photophysical processes that can potentially overcome these limits. The acene series are a group of organic chromophores that fulfill the strict energetic requirements to perform SF and TTA via there singlet (S1) and triplet (T1) states.A series of rigidly coupled acene dimers were photophysically characterized to probe fundamental aspects of SF and TTA. Tetracene and pentacene based dimers were both shown to undergo SF on the ultrafast timescale based on the observed rate constant (kSF). While the pentacene dimer measured a unity SF yield the tetracene dimer was only ~50 % due to differences in the SF driving force (ΔG). Studies of the tetracene dimer were also performed in a polar solvent environment to measure the impact of the charge-transfer (CT) state, an important intermediate state in the SF process. They showed that CT state formation to be parasitic to productive SF. Another tetracene dimer paired with a metal phthalocyanine sensitizer were used to generate anti-Stokes emission to study TTA upconversion (TTA-UC). Compared to a monomer reference the dimer demonstrated increased upconversion photoluminescence. Kinetic modeling of upconversion system showed this result to be due to enhancement of the TTA rate constant (kTTA).

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2024

Mode of access: World Wide Web

ISBN: 9798379527815Subjects--Topical Terms:

1148725
Physical chemistry.
Subjects--Index Terms:

Organic dimersIndex Terms--Genre/Form:

554714
Electronic books.

Photophysical Exploration of Rigidly Coupled Dimers for Singlet Fission and Triplet-Triplet Annihilation Upconversion.
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520 $a The Sun is a nearly unlimited source of energy that can be used on Earth to power society without substantial impact to the broader environment that humanity depends on. Decades of work by the scientific community have gone into understanding the science of solar energy and engineering it for useful application. Fundamental limits prevent taking full advantage of available solar energy. Exciton downconversion/upconversion in organic systems, also known as singlet fission (SF) and triplet-triplet annihilation (TTA), are photophysical processes that can potentially overcome these limits. The acene series are a group of organic chromophores that fulfill the strict energetic requirements to perform SF and TTA via there singlet (S1) and triplet (T1) states.A series of rigidly coupled acene dimers were photophysically characterized to probe fundamental aspects of SF and TTA. Tetracene and pentacene based dimers were both shown to undergo SF on the ultrafast timescale based on the observed rate constant (kSF). While the pentacene dimer measured a unity SF yield the tetracene dimer was only ~50 % due to differences in the SF driving force (ΔG). Studies of the tetracene dimer were also performed in a polar solvent environment to measure the impact of the charge-transfer (CT) state, an important intermediate state in the SF process. They showed that CT state formation to be parasitic to productive SF. Another tetracene dimer paired with a metal phthalocyanine sensitizer were used to generate anti-Stokes emission to study TTA upconversion (TTA-UC). Compared to a monomer reference the dimer demonstrated increased upconversion photoluminescence. Kinetic modeling of upconversion system showed this result to be due to enhancement of the TTA rate constant (kTTA).
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