Energy transfer process in dendrimers containing a perylene-terrylene donor-acceptor system investigated by femtosecond multicolor transient absorption spectroscopy

2004 ◽  
pp. 503-506
Author(s):  
G. Schweitzer ◽  
S. Jordens ◽  
G. De Belder ◽  
M. Lor ◽  
E. Fron ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Absorption Spectroscopy ◽  
Transfer Process ◽  
Transient Absorption ◽  
Energy Transfer Process ◽  
Transient Absorption Spectroscopy ◽  
Donor Acceptor

Decoupling the artificial special pair to slow down the rate of singlet energy transfer

2012 ◽  
Vol 16 (05n06) ◽  
pp. 685-694 ◽  
Author(s):  
Pierre D. Harvey ◽  
Adam Langlois ◽  
Mikhail Filatov ◽  
Daniel Fortin ◽  
Kei Ohkubo ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Absorption Spectroscopy ◽  
Density Functional ◽  
Transient Absorption ◽  
Geometry Optimization ◽  
Transient Absorption Spectroscopy ◽  
Free Base ◽  
Functional Theory ◽  
Time Resolved ◽  
Slow Rise

Trimer 2, composed of a cofacial heterobismacrocycle, octamethyl-porphyrin zinc(II) and bisarylporphyrin zinc(II) held by an anthracenyl spacer, and a flanking acceptor, bisarylporphyrin free-base ( Ar = -3,5-(t Bu )2 C 6 H 3), has been studied by means of absorption spectroscopy, "steady state and time-resolved fluorescence" and fs transient absorption spectroscopy, and density functional theory (DFT) in order to assess the effect of decoupling the chromophores' low energy MOs on the rate of the singlet, S1, energy transfer, k ET , compared to a recently reported work on a heavily coupled trimeric system, Trimer 1, [biphenylenebis(n-nonyl)porphyrin zinc(II)]-bisarylporphyrin free-base ( Ar = -3,5-(t Bu )2 C 6 H 3). The position of the 0–0 peaks of the absorption and fluorescence spectra of Trimer 2 indicates that these porphyrin units are respectively energy donor 1, donor 2, and acceptor. The DFT computations confirm that the MOs of the cofacial donor 1-donor 2 dyad are decoupled, but significant MO coupling between donor 2 and acceptor 1 is still present despite the strong dihedral angle between their respective average planes (77.5°: geometry optimization by DFT). The fs transient absorption spectra exhibit a clear S1–Sn fingerprint of the bisarylporphyrin zinc(II) chromophore and the kinetic trace exhibits a slow rise time of 87 ps, due to a S1 donor 1 → donor 2 ET. The transient species donor 2 and acceptor decay respectively in the short (~1.5) ns and 6 ns time scale.

Energy transfer within pc trimers of mastigocladus laminosus studied by picosecond time-resolved transient absorption spectroscopy

1988 ◽  
Vol 43 (1-2) ◽  
pp. 55-62 ◽  
Author(s):  
S. Schneider ◽  
P. Geiselhart ◽  
S. Siebzehnrübl ◽  
R. Fischer ◽  
H. Scheer
Keyword(s):  
Energy Transfer ◽  
Least Squares ◽  
Absorption Spectroscopy ◽  
Transient Absorption ◽  
Transient Absorption Spectroscopy ◽  
Transfer Time ◽  
Acceptor State ◽  
Time Resolved ◽  
Picosecond Pulses ◽  
Exponential Fit

The transient absorption recovery induced in phycocyanin trimers by picosecond pulses of variable wavelength (570-620 nm) has been recorded and analyzed by applying a least-squares multi-exponential fit procedure. The results suggest that in native PC trimers the chromophores exhibit a microheterogeneity with the effect that the derived apparent lifetimes are functions of excitation and probing wavelength. It is suggested that, due to strong excitonic coupling between a-84 and β-84 chromophores, the lifetime of the terminal acceptor state is reduced to about 900 ps; the apparent energy transfer time from chromophore β-155 to a-84 and β-84 chromophores varies between 20-50 ps depending on the actual chromophore-protein arrangement (microheterogeneity)

scholarly journals Carrier Formation Dynamics in Prototypical Organic Solar Cells as Investigated by Transient Absorption Spectroscopy

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Yutaka Moritomo ◽  
Kouhei Yonezawa ◽  
Takeshi Yasuda
Keyword(s):  
Solar Cells ◽  
Absorption Spectroscopy ◽  
Organic Solar Cells ◽  
Transient Absorption ◽  
Temporal Evolution ◽  
Carrier Dynamics ◽  
Transient Absorption Spectroscopy ◽  
Decay Component ◽  
Formation Dynamics ◽  
Donor Acceptor

Subpicosecond transient absorption spectroscopy is a powerful tool used to clarify the exciton and carrier dynamics within the organic solar cells (OSCs). In this review article, we introduce a method to determine the absolute numbers of the excitons and carriers against delay time (t) only from the photoinduced absorption (PIA) and electrochemically induced absorption (EIA) spectra. Application of this method to rr-P3HT-, PTB7-, and SMDPPEH-based OSCs revealed common aspects of the carrier formation dynamics. First, the temporal evolution of the numbers of the excitons and carriers indicates that the late decay component of exciton does not contribute to the carrier formation process. This is probably because the late component has not enough excess energy to separate into the electron and hole across the donor/acceptor (D/A) interface. Secondly, the spectroscopy revealed that the exciton-to-carrier conversion process is insensitive to temperature. This observation, together with the fast carrier formation time in OSCs, is consistent with the hot exciton picture.

Single-molecule spectroscopy and femtosecond transient absorption studies on the excitation energy transfer process in ApcE(1–240) dimers

2015 ◽  
Vol 17 (20) ◽  
pp. 13387-13396 ◽  
Author(s):  
Saran Long ◽  
Meng Zhou ◽  
Kun Tang ◽  
Xiao-Li Zeng ◽  
Yingli Niu ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Excitation Energy ◽  
Single Molecule ◽  
Transfer Process ◽  
Transient Absorption ◽  
Energy Transfer Process ◽  
Excitation Energy Transfer ◽  
Single Molecule Spectroscopy ◽  
Femtosecond Transient Absorption ◽  
Absorption Studies

The red-shifted absorption of ApcE dimers results from extending chromophore conformation, which does not depend on strong exction coupling.

Modulating absorption and charge transfer in bodipy-carbazole donor–acceptor dyads through molecular design

2019 ◽  
Vol 48 (23) ◽  
pp. 8488-8501 ◽  
Author(s):  
John Strahan ◽  
Bhooshan C. Popere ◽  
Piyachai Khomein ◽  
Craig A. Pointer ◽  
Shea M. Martin ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Absorption Spectroscopy ◽  
Transient Absorption ◽  
Molecular Design ◽  
Transient Absorption Spectroscopy ◽  
Excited State Dynamics ◽  
Donor Acceptor

Bodipy-based donor–acceptor dyads were evaluated using transient absorption spectroscopy to reveal the influence of beta vs. meso substitution on excited-state dynamics.

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