Morphology independent triplet formation in pentalene films: Singlet fission as the triplet formation mechanism

2019 ◽  
Vol 151 (12) ◽  
pp. 124701 ◽  
Author(s):  
Long Wang ◽  
Yishi Wu ◽  
Yanping Liu ◽  
Lanfen Wang ◽  
Jiannian Yao ◽  
...  
Keyword(s):  
Formation Mechanism ◽  
Singlet Fission ◽  
Triplet Formation

scholarly journals Unveiling the concentration dependent direct triplet formation via singlet fission in a tetracene derivative

2019 ◽  
Vol 205 ◽  
pp. 09031
Author(s):  
Nikolaus Wollscheid ◽  
Nicolo Alagna ◽  
J. Luis Perez Lustres ◽  
Tiago Buckup ◽  
Sebastian Hahn ◽  
...  
Keyword(s):  
Thin Films ◽  
Underlying Mechanism ◽  
Intersystem Crossing ◽  
Singlet Fission ◽  
Concentrated Solutions ◽  
Triplet Formation

Singlet fission is slowed down on diffusional timescales in highly concentrated solutions compared to thin films for a tetracene-like molecule. The underlying mechanism suggests competing intersystem crossing and singlet fission, where in the latter singlets are converted directly to triplets without an intermediate excimer state.

Competitive Triplet Formation and Recombination in Crystalline Films of Perylenediimide Derivatives: Implications for Singlet Fission

2020 ◽  
Vol 124 (21) ◽  
pp. 11574-11585 ◽  
Author(s):  
Saghar Masoomi-Godarzi ◽  
Christopher R. Hall ◽  
Bolong Zhang ◽  
Mark A. Gregory ◽  
Jonathan M. White ◽  
...  
Keyword(s):  
Singlet Fission ◽  
Crystalline Films ◽  
Triplet Formation

scholarly journals Using Structurally Well-Defined Norbornyl-Bridged Acene Dimers to Map a Mechanistic Landscape for Correlated Triplet Formation in Singlet Fission

2019 ◽  
Vol 141 (14) ◽  
pp. 5961-5971 ◽  
Author(s):  
Alexander T. Gilligan ◽  
Ethan G. Miller ◽  
Tarek Sammakia ◽  
Niels H. Damrauer
Keyword(s):  
Singlet Fission ◽  
Triplet Formation

scholarly journals Ultrafast spectroscopy reveals singlet fission, ionization and excimer formation in perylene film

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wenjun Ni ◽  
Licheng Sun ◽  
Gagik G. Gurzadyan
Keyword(s):  
Radical Cation ◽  
Transient Absorption ◽  
Photovoltaic Devices ◽  
Singlet Fission ◽  
Time Resolved ◽  
Singlet Exciton ◽  
Femtosecond Transient Absorption ◽  
Photovoltaic Applications ◽  
Singlet Exciton Fission ◽  
Triplet Formation

AbstractSinglet exciton fission (SF) is a spin-allowed process whereby two triplet excitons are created from one singlet exciton. This phenomenon can offset UV photon energy losses and enhance the overall efficiency in photovoltaic devices. For this purpose, it requires photostable commercially available SF materials. Excited state dynamics in pure perylene film, ease of commercial production, is studied by time-resolved fluorescence and femtosecond transient absorption techniques under different photoexcitation energies. In film, polycrystalline regions contain perylene in H-type aggregate form. SF takes place from higher excited states of these aggregates in ultrafast time scale < 30 fs, reaching a triplet formation quantum yield of 108%. Moreover, at λex = 450 nm singlet fission was detected as a result of two-quantum absorption. Other competing relaxation channels are excimer (1 ps) and dimer radical cation formation (< 30 fs). Excimer radiatively relaxes within 19 ns and radical cation recombines in 3.2 ns. Besides, exciton self-trapping by crystal lattice distortions occurs within hundreds of picosecond. Our results highlight potential of simple-fabricated perylene films with similar properties as high-cost single crystal in SF based photovoltaic applications.

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