scholarly journals Magnetic field dependence of singlet fission in solutions of diphenyl tetracene

2015 ◽  
Vol 373 (2044) ◽  
pp. 20140323 ◽  
Author(s):  
Nicholas J. Thompson ◽  
Eric Hontz ◽  
Wendi Chang ◽  
Troy Van Voorhis ◽  
Marc Baldo
Keyword(s):  
Magnetic Field ◽  
Field Dependence ◽  
Optoelectronic Devices ◽  
Magnetic Field Effects ◽  
Singlet Fission ◽  
Strong Fluorescence ◽  
Singlet Exciton ◽  
Fluorescence Modulation ◽  
Singlet Exciton Fission ◽  
Transfer State

Magnetic field effects provide a convenient and specific probe of singlet exciton fission within optoelectronic devices. Here, we demonstrate that this tool may also be applied to screen potential fission material candidates in solution. We characterize the phenomenon in diphenyl tetracene (DPT), which shows strong fluorescence modulation and the expected field dependence in its transient decay as a function of concentration. Solution measurements may also be used to test for the presence of an intermediate charge transfer state, but we observe no changes to the field dependence of DPT singlet exciton fission in toluene relative to chloroform.

scholarly journals Singlet fission in thin films of metallo-supramolecular polymers with ditopic thiophene-bridged terpyridine ligands

2017 ◽  
Vol 5 (32) ◽  
pp. 8041-8051 ◽  
Author(s):  
David Rais ◽  
Jiří Pfleger ◽  
Miroslav Menšík ◽  
Alexander Zhigunov ◽  
Pavla Štenclová ◽  
...  
Keyword(s):  
Transient Absorption ◽  
Transient Absorption Spectroscopy ◽  
Supramolecular Polymers ◽  
Uv Laser ◽  
Singlet Fission ◽  
Thin Solid Films ◽  
Singlet Exciton ◽  
Solid Films ◽  
Terpyridine Ligands ◽  
Singlet Exciton Fission

Ultrafast singlet exciton fission in thin solid films after UV laser photoexcitation was observed using transient absorption spectroscopy.

scholarly journals Singlet exciton fission via an intermolecular charge transfer state in coevaporated pentacene-perfluoropentacene thin films

2019 ◽  
Vol 151 (16) ◽  
pp. 164706 ◽  
Author(s):  
Vincent O. Kim ◽  
Katharina Broch ◽  
Valentina Belova ◽  
Y. S. Chen ◽  
Alexander Gerlach ◽  
...  
Keyword(s):  
Thin Films ◽  
Charge Transfer ◽  
Charge Transfer State ◽  
Singlet Exciton ◽  
Intermolecular Charge Transfer ◽  
Singlet Exciton Fission ◽  
Transfer State

scholarly journals Perdeuteration of poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene] (d-MEH-PPV): control of microscopic charge-carrier spin–spin coupling and of magnetic-field effects in optoelectronic devices

2020 ◽  
Vol 8 (8) ◽  
pp. 2764-2771 ◽  
Author(s):  
Dani M. Stoltzfus ◽  
Gajadhar Joshi ◽  
Henna Popli ◽  
Shirin Jamali ◽  
Marzieh Kavand ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Charge Carrier ◽  
Optoelectronic Devices ◽  
Spin Coupling ◽  
Magnetic Field Effects ◽  
Field Effects ◽  
Spin Spin Coupling

Replacing all protons on a polymer by deuterium has a dramatic impact on spin-dependent properties of the material in devices.

scholarly journals Strategies for Design of Potential Singlet Fission Chromophores Utilizing a Combination of Ground State and Excited State Aromaticity Rules

2020 ◽  
Author(s):  
Ouissam El Bakouri ◽  
Joshua R. Smith ◽  
Henrik Ottosson
Keyword(s):  
Excited State ◽  
Excited States ◽  
Ground State ◽  
Geometric Model ◽  
Substituent Effects ◽  
Singlet Fission ◽  
Singlet Exciton ◽  
Singlet Exciton Fission ◽  
Homo Lumo ◽  
Potential Use

Singlet exciton fission photovoltaics requires chromophores with their lowest excited states arranged so that 2<i>E</i>(T<sub>1</sub>) < <i>E</i>(S<sub>1</sub>) and <i>E</i>(S<sub>1</sub>) < <i>E</i>(T<sub>2</sub>). Herein, qualitative theory and quantum chemical calculations are used to develop explicit strategies on how to use Baird’s 4<i>n</i> rule on excited state aromaticity, combined with Hückel’s 4<i>n</i>+2 rule for ground state aromaticity, to tailor new potential chromophores for singlet fission. We first analyze the <i>E</i>(T<sub>1</sub>), <i>E</i>(S<sub>1</sub>) and <i>E</i>(T<sub>2</sub>) of benzene and cyclobutadiene (<b>CBD</b>) as, respectively, excited state antiaromatic and aromatic archetypes, and reveal that <b>CBD </b>fulfils the criteria on the state ordering for a singlet fission chromophore. We then look at fulvenes, a class of compounds that can be tuned by choice of substituents from Baird-antiaromatic to Baird-aromatic in T<sub>1</sub> and S<sub>1</sub>, and from Hückel-aromatic to Hückel-antiaromatic in S<sub>0</sub>. The T<sub>1</sub> and S<sub>1</sub> states of most substituted fulvenes (159 of 225) are described by singly excited HOMO→LUMO configurations, providing a rational for the simultaneous tuning of <i>E</i>(T<sub>1</sub>) and <i>E</i>(S<sub>1</sub>) along an approximate (anti)aromaticity coordinate. Key to the tunability is the exchange integral (K<sub>H,L</sub>), which ideally is constant throughout the compound class, providing a constant D<i>E</i>(S<sub>1</sub>-T<sub>1</sub>). This leads us to a geometric model for identification of singlet fission chromophores, and we explore what factors limit the model. Candidates with calculated <i>E</i>(T<sub>1</sub>) of ~1 eV or higher are identified among benzannelated 4<i>n</i>pi-electron compound classes and siloles. In brief, it is clarified how the joint utilization of Baird’s 4<i>n</i> and Hückel’s 4<i>n</i>+2 rules, together with substituent effects (electronic and steric) and benzannelation, can be used to tailor new chromophores with potential use in singlet fission photovoltaics.<br>

scholarly journals Strategies for Design of Potential Singlet Fission Chromophores Utilizing a Combination of Ground State and Excited State Aromaticity Rules

2020 ◽  
Author(s):  
Ouissam El Bakouri ◽  
Joshua R. Smith ◽  
Henrik Ottosson
Keyword(s):  
Excited State ◽  
Excited States ◽  
Ground State ◽  
Geometric Model ◽  
Substituent Effects ◽  
Singlet Fission ◽  
Singlet Exciton ◽  
Singlet Exciton Fission ◽  
Homo Lumo ◽  
Potential Use

Singlet exciton fission photovoltaics requires chromophores with their lowest excited states arranged so that 2<i>E</i>(T<sub>1</sub>) < <i>E</i>(S<sub>1</sub>) and <i>E</i>(S<sub>1</sub>) < <i>E</i>(T<sub>2</sub>). Herein, qualitative theory and quantum chemical calculations are used to develop explicit strategies on how to use Baird’s 4<i>n</i> rule on excited state aromaticity, combined with Hückel’s 4<i>n</i>+2 rule for ground state aromaticity, to tailor new potential chromophores for singlet fission. We first analyze the <i>E</i>(T<sub>1</sub>), <i>E</i>(S<sub>1</sub>) and <i>E</i>(T<sub>2</sub>) of benzene and cyclobutadiene (<b>CBD</b>) as, respectively, excited state antiaromatic and aromatic archetypes, and reveal that <b>CBD </b>fulfils the criteria on the state ordering for a singlet fission chromophore. We then look at fulvenes, a class of compounds that can be tuned by choice of substituents from Baird-antiaromatic to Baird-aromatic in T<sub>1</sub> and S<sub>1</sub>, and from Hückel-aromatic to Hückel-antiaromatic in S<sub>0</sub>. The T<sub>1</sub> and S<sub>1</sub> states of most substituted fulvenes (159 of 225) are described by singly excited HOMO→LUMO configurations, providing a rational for the simultaneous tuning of <i>E</i>(T<sub>1</sub>) and <i>E</i>(S<sub>1</sub>) along an approximate (anti)aromaticity coordinate. Key to the tunability is the exchange integral (K<sub>H,L</sub>), which ideally is constant throughout the compound class, providing a constant D<i>E</i>(S<sub>1</sub>-T<sub>1</sub>). This leads us to a geometric model for identification of singlet fission chromophores, and we explore what factors limit the model. Candidates with calculated <i>E</i>(T<sub>1</sub>) of ~1 eV or higher are identified among benzannelated 4<i>n</i>pi-electron compound classes and siloles. In brief, it is clarified how the joint utilization of Baird’s 4<i>n</i> and Hückel’s 4<i>n</i>+2 rules, together with substituent effects (electronic and steric) and benzannelation, can be used to tailor new chromophores with potential use in singlet fission photovoltaics.<br>

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