fs–ps Exciton dynamics in a stretched tetraphenylsquaraine polymer

2019 ◽  
Vol 21 (28) ◽  
pp. 15346-15355 ◽  
Author(s):  
Maximilian H. Schreck ◽  
Lena Breitschwerdt ◽  
Henning Marciniak ◽  
Marco Holzapfel ◽  
David Schmidt ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Time Scale ◽  
Exciton Dynamics ◽  
Fast Light

A squaraine polymer shows surprisingly fast light induced energy transfer between two different structural sections on the ps/fs time scale.

Exciton dynamics and energy transfer in beryllium oxide crystals with defects

1998 ◽  
Vol 76-77 ◽  
pp. 467-469 ◽  
Author(s):  
K.V. Bautin ◽  
S.V. Kudyakov ◽  
I.N. Ogorodnikov ◽  
A.V. Kruzhalov ◽  
V.Yu. Yakovlev
Keyword(s):  
Energy Transfer ◽  
Beryllium Oxide ◽  
Exciton Dynamics ◽  
Oxide Crystals

Inter-island energy transfer and in-plane exciton migration in AlGaAs/GaAs quantum wells detected by exciton dynamics

1998 ◽  
Vol 23 (1) ◽  
pp. 107-111
Author(s):  
M. Godlewski ◽  
P.O. Holz ◽  
J.P. Bergman ◽  
B. Monemar ◽  
K. Reginski ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Quantum Wells ◽  
Exciton Dynamics ◽  
Exciton Migration

Fast Energy Transfer and Exciton Dynamics in Chlorosomes of the Green Sulfur BacteriumChlorobium tepidum

1998 ◽  
Vol 102 (23) ◽  
pp. 4392-4398 ◽  
Author(s):  
Jakub Pšenčík ◽  
Tomáš Polívka ◽  
Petr Němec ◽  
Juraj Dian ◽  
Jakub Kudrna ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Exciton Dynamics ◽  
Green Sulfur

Through space singlet energy transfers in light-harvesting systems and cofacial bisporphyrin dyads

2010 ◽  
Vol 14 (01) ◽  
pp. 55-63 ◽  
Author(s):  
Pierre D. Harvey ◽  
Christine Stern ◽  
Claude P. Gros ◽  
Roger Guilard
Keyword(s):  
Electron Transfer ◽  
Energy Transfer ◽  
Time Scale ◽  
Light Harvesting ◽  
Energy Migration ◽  
Triplet Energy ◽  
Energy Transfers ◽  
Harvesting Systems ◽  
Controlled Structure ◽  
And Migration

Recent discoveries from our research groups on the photophysics of a few cofacial bisporphyrin dyads for through space singlet and triplet energy transfers raised several important investigations about the mechanism of energy transfers and energy migration in light-harvesting devices, notably LH II, in the heavily investigated purple photosynthetic bacteria. The key feature is that for face-to-face and slipped dyads with controlled structure using rigid spacers or spacers with limited flexibilities, our fastest rates for singlet energy transfer are in the 10 × 109 s -1 (i.e. 100 ps time scale) for donor-acceptor distances of ~3.5–3.6 Å. The time scale for energy transfers between different bacteriochlorophylls, notably B800*→B850, is in the ps despite the long Mg ⋯ Mg separation (~18 Å). This short rate drastically contrasts with the well-accepted Förster theory. This review focuses on the photophysical processes and dynamics in LH II and compares these parameters with our investigated model dyads build upon octa-etio-porphyrin chromophores and rigid and semi-rigid spacers. The recently discovered role of the rhodopin glucoside (carotenoid) will be analyzed as possible relay for energy transfers, including the possibility of uphill processes at room temperature. In this context the concept of energy migration may be complemented by parallel relays and uphill processes. It is also becoming more obvious that the irreversible electron transfer at the reaction center (electron transfer from the special pair to the phaeophytin) renders the rates for energy transfer and migration faster precluding all possibility of back transfers.

scholarly journals Understanding the influence of disorder on the exciton dynamics and energy transfer in Zn-phthalocyanine H-aggregates

2018 ◽  
Vol 20 (34) ◽  
pp. 22331-22341 ◽  
Author(s):  
Sandra Doria ◽  
Andrea Lapini ◽  
Mariangela Di Donato ◽  
Roberto Righini ◽  
Nicolò Azzaroli ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Exciton Dynamics ◽  
Aggregation Effect ◽  
Coherent Spectroscopy

We aim to get insight the aggregation effect on the exciton behavior in phthalocyanine systems with coherent spectroscopy.

Shape-persistent poly-porphyrins assembled by a central truxene: synthesis, structure, and singlet energy transfer behaviors

2013 ◽  
Vol 17 (01n02) ◽  
pp. 44-55 ◽  
Author(s):  
Hai-Jun Xu ◽  
Bin Du ◽  
Claude P. Gros ◽  
Philippe Richard ◽  
Jean-Michel Barbe ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Fluorescence Lifetime ◽  
Time Scale ◽  
Selective Excitation ◽  
Methyl Groups ◽  
Flexible Systems ◽  
Relative Rigidity ◽  
Energy Donor ◽  
Donor And Acceptor

Four dyad systems composed of a central truxene and either one or three β-substituted zinc(II) porphyrins (ZnP: TruZnP (7) and TruTriZnP (9)) or free-bases (H2P: TruP (6) and TruTriP (8)) have been prepared. The presence of β-methyl groups minimizes π-conjugation through the quasi right angle made by the porphyrin and the truxene planes, and renders these dyads relatively rigid. The position of the absorption and emission 0–0 peaks confirms the role of the truxene and porphyrin as the energy donor and acceptor, respectively. Selective excitation of the truxene results in an efficient singlet energy transfer (S1 ET) from the truxene to the porphyrin unit. The rates for S1 ET (k ET ) are extracted from the change in the fluorescence lifetime of truxene in the presence and absence of the acceptor, and are temperature independent, (TruP (6), TruTriP (8), TruZnP (7) and TruTriZnP (9) are 5.0, 1.4, 1.0 and 1.4 at 298 K and 5.9, 1.3, 2.6, and 0.86 (ns)-1 at 77 K, respectively), consistent with their relative rigidity. These k ET 's are similar to other related but more flexible systems reported by one of us (Inorg. Chem.2011, 50, 11493–11505). The k ET 's time scale was assumed, based on modeling, to be related with hindered rotations about the truxene-porphyrin C–C bonds due to steric hexyl–hexyl interactions. This work confirms this earlier conclusion was correct.

A Mechanism for Local Dissipation of Internal Tides Generated at Rough Topography

2011 ◽  
Vol 41 (2) ◽  
pp. 378-395 ◽  
Author(s):  
Maxim Nikurashin ◽  
Sonya Legg
Keyword(s):  
Energy Transfer ◽  
Energy Dissipation ◽  
Time Scale ◽  
Wave Breaking ◽  
Large Scale ◽  
Flow Characteristics ◽  
Internal Tides ◽  
Tidal Mixing ◽  
Topographic Roughness ◽  
Basin Region

Abstract Fine- and micro-structure observations indicate that turbulent mixing is enhanced within O(1) km above rough topography. Enhanced mixing is associated with internal wave breaking and, in many regions of the ocean, has been linked to the breaking and dissipation of internal tides. The generation and dissipation of internal tides are explored in this study using a high-resolution two-dimensional nonhydrostatic numerical model, which explicitly resolves the instabilities leading to wave breaking, configured in an idealized domain with a realistic multiscale topography and flow characteristics. The control simulation, chosen to represent the Brazil Basin region, produces a vertical profile of energy dissipation and temporal characteristics of finescale motions that are consistent with observations. Results suggest that a significant fraction of mixing in the bottom O(1) km of the ocean is sustained by the transfer of energy from the large-scale internal tides to smaller-scale internal waves by nonlinear wave–wave interactions. The time scale of the energy transfer to the smaller scales is estimated to be on the order of a few days. A suite of sensitivity experiments is carried out to examine the dependence of the energy transfer time scale and energy dissipation on topographic roughness, tidal amplitude, and Coriolis frequency parameters. Implications for tidal mixing parameterizations are discussed.

Sign in / Sign up

Export Citation Format

Share Document