scholarly journals Excimer formation dynamics in the isolated tetracene dimer

2021 ◽  
Author(s):  
Joscha Hoche ◽  
Marco Flock ◽  
Xincheng Miao ◽  
Luca N. Philipp ◽  
Michael Wenzel ◽  
...  
Keyword(s):  
Organic Electronics ◽  
High Significance ◽  
Formation Dynamics ◽  
Triplet Pair ◽  
Excimer Formation ◽  
Pair State

The understanding of excimer formation and its interplay with the singlet-correlated triplet pair state 1(TT) is of high significance for the development of efficient organic electronics. Here, we study the...

Ultrafast Exciton Delocalization, Localization, and Excimer Formation Dynamics in a Highly Defined Perylene Bisimide Quadruple π-Stack

2018 ◽  
Vol 140 (12) ◽  
pp. 4253-4258 ◽  
Author(s):  
Christina Kaufmann ◽  
Woojae Kim ◽  
Agnieszka Nowak-Król ◽  
Yongseok Hong ◽  
Dongho Kim ◽  
...  
Keyword(s):  
Perylene Bisimide ◽  
Formation Dynamics ◽  
Excimer Formation

scholarly journals Revealing the contest between triplet-triplet exchange and triplet-triplet energy transfer coupling in correlated triplet pair states in singlet fission

2021 ◽  
Author(s):  
Vibin Abraham ◽  
Nicholas Mayhall
Keyword(s):  
Energy Transfer ◽  
Exchange Interaction ◽  
Entangled State ◽  
Separation Mechanism ◽  
Singlet Fission ◽  
Triplet Energy ◽  
Triplet Pair ◽  
Triplet Energy Transfer ◽  
State 1 ◽  
Pair State

Understanding the separation of the correlated triplet pair state 1(TT) intermediate is critical for leveraging singlet fission to improve solar cell efficiency. This separation mechanism is dominated by two key interactions: (i) the exchange interaction (K) between the triplets which leads to the spin splitting of the biexciton state into 1(TT),3(TT) and 5(TT) states, and (ii) the triplet-triplet energy transfer integral (t) which enables the formation of the spatially separated (but still spin entangled) state 1(T...T). We develop a simple ab initio technique to compute both the biexciton exchange (K) and biexciton transfer coupling. Our key findings reveal new conditions for successful correlated triplet pair state dissociation. The biexciton exchange interaction needs to be ferromagnetic or negligible to the triplet energy transfer for favourable dissociation. We also explore the effect of chromophore packing to reveal geometries where these conditions are achieved for tetracene.

Intramolecular excimer formation dynamics of bis (9-fluorenyl) methane

1991 ◽  
Vol 176 (5) ◽  
pp. 453-458 ◽  
Author(s):  
Young Boong Chung ◽  
Du-Jeon Jang ◽  
Dongho Kim ◽  
Minyung Lee ◽  
Hyun Sook Kim ◽  
...  
Keyword(s):  
Formation Dynamics ◽  
Intramolecular Excimer ◽  
Excimer Formation

scholarly journals The entangled triplet pair state in acene and heteroacene materials

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Chaw Keong Yong ◽  
Andrew J. Musser ◽  
Sam L. Bayliss ◽  
Steven Lukman ◽  
Hiroyuki Tamura ◽  
...  
Keyword(s):  
Triplet Pair ◽  
Pair State

scholarly journals Singlet fission of hot excitons in π -conjugated polymers

2015 ◽  
Vol 373 (2044) ◽  
pp. 20140327 ◽  
Author(s):  
Yaxin Zhai ◽  
Chuanxiang Sheng ◽  
Z. Valy Vardeny
Keyword(s):  
Conjugated Polymers ◽  
Threshold Energy ◽  
High Energy ◽  
Triplet Exciton ◽  
Singlet Fission ◽  
General Process ◽  
Singlet Exciton ◽  
Triplet Pair ◽  
Luminescent Polymer ◽  
Pair State

We used steady-state photoinduced absorption (PA), excitation dependence (EXPA( ω )) spectrum of the triplet exciton PA band, and its magneto-PA (MPA( B )) response to investigate singlet fission (SF) of hot excitons into two separated triplet excitons, in two luminescent and non-luminescent π -conjugated polymers. From the high energy step in the triplet EXPA( ω ) spectrum of the luminescent polymer poly(dioctyloxy)phenylenevinylene (DOO-PPV) films, we identified a hot-exciton SF (HE-SF) process having threshold energy at E ≈2 E T (=2.8 eV, where E T is the energy of the lowest lying triplet exciton), which is about 0.8 eV above the lowest singlet exciton energy. The HE-SF process was confirmed by the triplet MPA( B ) response for excitation at E >2 E T , which shows typical SF response. This process is missing in DOO-PPV solution, showing that it is predominantly interchain in nature. By contrast, the triplet EXPA( ω ) spectrum in the non-luminescent polymer polydiacetylene (PDA) is flat with an onset at E = E g (≈2.25 eV). From this, we infer that intrachain SF that involves a triplet–triplet pair state, also known as the ‘dark’ 2A g exciton, dominates the triplet photogeneration in PDA polymer as E g >2 E T . The intrachain SF process was also identified from the MPA( B ) response of the triplet PA band in PDA. Our work shows that the SF process in π -conjugated polymers is a much more general process than thought previously.

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