Mapping of exciton–exciton annihilation in MEH-PPV by time-resolved spectroscopy: experiment and microscopic theory

2017 ◽  
Vol 19 (47) ◽  
pp. 31989-31996 ◽  
Author(s):  
Kilian Hader ◽  
Cristina Consani ◽  
Tobias Brixner ◽  
Volker Engel
Keyword(s):  
Transient Absorption ◽  
Laser Intensity ◽  
Microscopic Theory ◽  
Time Resolved ◽  
Time Resolved Spectroscopy ◽  
Spectroscopy Experiment ◽  
Exciton Annihilation

Transient absorption traces taken on samples of the polymer MEH-PPV are measured as a function of the laser intensity.

scholarly journals Transient absorption spectroscopy and photochemical reactivity of CAU-8

2015 ◽  
Vol 3 (15) ◽  
pp. 3607-3613 ◽  
Author(s):  
Herme G. Baldovi ◽  
Martin Krüger ◽  
Helge Reinsch ◽  
Mercedes Alvaro ◽  
Norbert Stock ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Transient Absorption ◽  
Transient Absorption Spectroscopy ◽  
Time Resolved ◽  
Photochemical Reactivity ◽  
Time Resolved Spectroscopy

Time-resolved spectroscopy has provided evidence of the nature of the transients upon irradiation of CAU-8 and the photochemical reactivity has been used to promote styrene polymerisation and linker transformation.

Roles of adsorption sites in electron transfer from CdS quantum dots to molecular catalyst cobaloxime studied by time-resolved spectroscopy

2016 ◽  
Vol 18 (26) ◽  
pp. 17389-17397 ◽  
Author(s):  
Yun Ye ◽  
Yuxing Xu ◽  
Lei Huang ◽  
Dayong Fan ◽  
Zhaochi Feng ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Electron Transfer ◽  
Absorption Spectroscopy ◽  
Transient Absorption ◽  
Transient Absorption Spectroscopy ◽  
Cds Quantum Dots ◽  
Time Resolved ◽  
Time Resolved Spectroscopy ◽  
Molecular Catalyst ◽  
Adsorption Sites

Electron transfer from CdS quantum dots (QDs) to cobaloxime (Co(dmgH)2pyCl) is demonstrated by transient absorption spectroscopy (TAS), and further confirmed using photoluminescence (PL) techniques.

scholarly journals Time-Resolved Spectroscopy of Polymethine J-Aggregates

1991 ◽  
Vol 11 (1) ◽  
pp. 1-12 ◽  
Author(s):  
K.-H. Feller ◽  
R. Gadonas ◽  
V. Krasauskas ◽  
V. Fidler ◽  
S. Vajda
Keyword(s):  
Steady State ◽  
Transient Absorption ◽  
Decay Kinetics ◽  
Time Resolved ◽  
Absorption And Fluorescence Spectroscopy ◽  
Transient Absorption Spectra ◽  
J Aggregates ◽  
Exciton Annihilation ◽  
Deactivation Process ◽  
Aggregate Structures

The deactivation process of J-aggregates of DDEOCI (3,3'-diethyl-5,5'-diphenyl-9-ethyl-oxacarbocyanine iodide) was investigated by means of steady-state and time-resolved absorption and fluorescence spectroscopy. The decay kinetics as well as the transient absorption spectra have been analyzed including different aggregate structures and exciton-exciton annihilation.

Introduction to Time-Resolved Spectroscopy: Nanosecond Transient Absorption and Time-Resolved Fluorescence of Eosin B

2018 ◽  
Vol 95 (5) ◽  
pp. 864-871 ◽  
Author(s):  
Erik P. Farr ◽  
Jason C. Quintana ◽  
Vanessa Reynoso ◽  
Josiah D. Ruberry ◽  
Wook R. Shin ◽  
...  
Keyword(s):  
Transient Absorption ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Time Resolved Spectroscopy ◽  
Eosin B

scholarly journals Photophysical properties and fluorosolvatochromism of D–π–A thiophene based derivatives

RSC Advances ◽  
2020 ◽  
Vol 10 (71) ◽  
pp. 43459-43471
Author(s):  
Hussain A. Z. Sabek ◽  
Ahmed M. M. Alazaly ◽  
Dina Salah ◽  
Hesham S. Abdel-Samad ◽  
Mohamed A. Ismail ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Fluorescence Emission ◽  
Time Resolved ◽  
Time Resolved Spectroscopy ◽  
Solvation Models

Solvation-dependent photophysical properties of two push–pull thiophene-based compounds with donor–π–acceptor (D–π–A) structures were investigated using absorption, fluorescence emission and time resolved spectroscopy, and supported by different solvation models.

scholarly journals Ultrafast proton release reaction and primary photochemistry of phycocyanobilin in solution observed with fs-time-resolved mid-IR and UV/Vis spectroscopy

2021 ◽  
Author(s):  
Maximilian Theiß ◽  
Merten Grupe ◽  
Tilman Lamparter ◽  
Maria Andrea Mroginski ◽  
Rolf Diller
Keyword(s):  
Density Functional ◽  
Transient Absorption ◽  
Vibrational Analysis ◽  
Density Functional Theory Calculations ◽  
Chem Phys ◽  
Molecular Structures ◽  
Ir Absorption ◽  
Time Resolved ◽  
Time Constants ◽  
Vis Spectroscopy

AbstractDeactivation processes of photoexcited (λex = 580 nm) phycocyanobilin (PCB) in methanol were investigated by means of UV/Vis and mid-IR femtosecond (fs) transient absorption (TA) as well as static fluorescence spectroscopy, supported by density-functional-theory calculations of three relevant ground state conformers, PCBA, PCBB and PCBC, their relative electronic state energies and normal mode vibrational analysis. UV/Vis fs-TA reveals time constants of 2.0, 18 and 67 ps, describing decay of PCBB*, of PCBA* and thermal re-equilibration of PCBA, PCBB and PCBC, respectively, in line with the model by Dietzek et al. (Chem Phys Lett 515:163, 2011) and predecessors. Significant substantiation and extension of this model is achieved first via mid-IR fs-TA, i.e. identification of molecular structures and their dynamics, with time constants of 2.6, 21 and 40 ps, respectively. Second, transient IR continuum absorption (CA) is observed in the region above 1755 cm−1 (CA1) and between 1550 and 1450 cm−1 (CA2), indicative for the IR absorption of highly polarizable protons in hydrogen bonding networks (X–H…Y). This allows to characterize chromophore protonation/deprotonation processes, associated with the electronic and structural dynamics, on a molecular level. The PCB photocycle is suggested to be closed via a long living (> 1 ns), PCBC-like (i.e. deprotonated), fluorescent species.

scholarly journals The role of spin in the degradation of organic photovoltaics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ivan Ramirez ◽  
Alberto Privitera ◽  
Safakath Karuthedath ◽  
Anna Jungbluth ◽  
Johannes Benduhn ◽  
...  
Keyword(s):  
Transient Absorption ◽  
Bulk Heterojunction ◽  
Critical Factor ◽  
Model Systems ◽  
Transient Absorption Spectroscopy ◽  
Triplet States ◽  
Paramagnetic Resonance ◽  
Time Resolved ◽  
A Charge

AbstractStability is now a critical factor in the commercialization of organic photovoltaic (OPV) devices. Both extrinsic stability to oxygen and water and intrinsic stability to light and heat in inert conditions must be achieved. Triplet states are known to be problematic in both cases, leading to singlet oxygen production or fullerene dimerization. The latter is thought to proceed from unquenched singlet excitons that have undergone intersystem crossing (ISC). Instead, we show that in bulk heterojunction (BHJ) solar cells the photo-degradation of C60 via photo-oligomerization occurs primarily via back-hole transfer (BHT) from a charge-transfer state to a C60 excited triplet state. We demonstrate this to be the principal pathway from a combination of steady-state optoelectronic measurements, time-resolved electron paramagnetic resonance, and temperature-dependent transient absorption spectroscopy on model systems. BHT is a much more serious concern than ISC because it cannot be mitigated by improved exciton quenching, obtained for example by a finer BHJ morphology. As BHT is not specific to fullerenes, our results suggest that the role of electron and hole back transfer in the degradation of BHJs should also be carefully considered when designing stable OPV devices.

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