Theory of triplet exciton polarons and photoinduced absorption in conjugated polymers

1994 ◽  
Vol 49 (20) ◽  
pp. 14113-14121 ◽  
Author(s):  
Yukihiro Shimoi ◽  
Shuji Abe
Keyword(s):  
Conjugated Polymers ◽  
Triplet Exciton ◽  
Photoinduced Absorption

Dynamic recombination of triplet exciton with trapped counterion in conjugated polymers

2020 ◽  
Vol 93 (9) ◽  
Author(s):  
Yadong Wang ◽  
Jianjun Liu ◽  
Yanxia Liu ◽  
Xiru Wang ◽  
Yan Meng
Keyword(s):  
Conjugated Polymers ◽  
Triplet Exciton

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.

Nonlinear Optical Properties of Two Thiophene-Based Polyconjugated Systems: Photoinduced Absorption and Third Harmonic Generation Spectroscopy

1989 ◽  
Vol 173 ◽  
Author(s):  
R. Zamboni ◽  
C. Taliani ◽  
G. Ruani ◽  
A. J. Pal ◽  
F. Kajzar
Keyword(s):  
Optical Properties ◽  
Conjugated Polymers ◽  
Harmonic Generation ◽  
Nonlinear Optical ◽  
Third Harmonic Generation ◽  
Nonlinear Optical Properties ◽  
Photoinduced Absorption ◽  
Third Harmonic ◽  
Optical Gap ◽  
The Third

ABSTRACTNonlinear optical properties of two thiophene-based conjugated polymers (PTT and PDTB) were studied by the photoinduced absorption spectroscopy and the third harmonic generation spectroscopy. The results obtained with these two methods are used to estimate the value of χ(3) in these materials. Resonant χ(3) are (2.0 ± 0.2) × 10−11 e.s.u. and (1.0 ± 0.1) × 10−11 e.s.u. for PTT and PDTB, respectively. χ(3) is shown to be related to the width of the optical gap through a sixth-power law. In PTT a vibronic structure due to the C = C stretching mode appears in the χ(3) spectrum.

Even Parity States in Ppv, Polythiophene and Polysilanes

1993 ◽  
Vol 328 ◽  
Author(s):  
F. Guo ◽  
M. Chandross ◽  
S. Mazumdar
Keyword(s):  
Conjugated Polymers ◽  
Parity State ◽  
Photoinduced Absorption ◽  
Absorption Data ◽  
Two Photon ◽  
Bond Alternation ◽  
Theoretical Evidence ◽  
Long Chains

ABSTRACTTwo photon absorptions (TPA) in conjugated polymers with large bond alternation are reinterpreted. TPA to the 2Ag in long chains should be tiny due to cancellation effects, and therefore the observed strong, narrow TPA is to a higher even parity state. We also present the first theoretical evidence for bound biexcitons, and explain recent photoinduced absorption data.

scholarly journals Direct evidence for singlet-triplet exciton annihilation in π-conjugated polymers

2002 ◽  
Vol 66 (23) ◽  
Author(s):  
E. J. W. List ◽  
U. Scherf ◽  
K. Müllen ◽  
W. Graupner ◽  
C.-H. Kim ◽  
...  
Keyword(s):  
Conjugated Polymers ◽  
Direct Evidence ◽  
Triplet Exciton ◽  
Exciton Annihilation

Model of transient photoinduced absorption with an exciton polaron in conjugated polymers

1998 ◽  
Vol 57 (11) ◽  
pp. 6386-6390 ◽  
Author(s):  
V. A. Shakin ◽  
S. Abe ◽  
Y. Shimoi
Keyword(s):  
Conjugated Polymers ◽  
Photoinduced Absorption
Sign in / Sign up

Export Citation Format

Share Document