Single-shot transient absorption spectroscopy of an organic film

MRS Advances ◽  
2018 ◽  
Vol 3 (59) ◽  
pp. 3453-3457 ◽  
Author(s):  
Kelly S. Wilson ◽  
Madelyn N. Scott ◽  
Cathy Y. Wong
Keyword(s):  
Transient Absorption ◽  
Film Formation ◽  
Signal To Noise Ratio ◽  
Transient Absorption Spectroscopy ◽  
Organic Films ◽  
Single Shot ◽  
Organic Film ◽  
Pump Probe ◽  
Exciton Dynamics ◽  
Absorption Measurements

ABSTRACTWe report single-shot transient absorption (SSTA) measurements of an organic film of 3,3’-Diethyloxatricarbocyanine iodide (DOTCI). In SSTA, the pump-probe time delay is spatially encoded by using a tilted pump pulse. Translation of the sample during SSTA measurements averages over any spatial heterogeneity in the film. We demonstrate that exciton dynamics measured with the single-shot technique agrees with traditional transient absorption measurements of the same film. A signal-to-noise ratio of ∼40 is achieved in 10 s. The ability to measure exciton dynamics in organic films will enable future SSTA measurements of exciton dynamics during the molecular aggregation events that result in film formation.

scholarly journals Exciton dynamics in DNA oligomers studied by broadband deep-UV transient absorption spectroscopy

2019 ◽  
Vol 205 ◽  
pp. 10006
Author(s):  
Benjamin Bauer ◽  
Malte Oppermann ◽  
Majed Chergui
Keyword(s):  
Absorption Spectroscopy ◽  
Transient Absorption ◽  
Transient Absorption Spectroscopy ◽  
Base Stacking ◽  
Dna Oligomers ◽  
Exciton Dynamics ◽  
Deep Uv ◽  
Strand Length ◽  
Absorption Measurements

We report broadband transient absorption measurements of adenine strands in the deep-UV (250-370 nm). By varying the strand length we resolve the interplay between inter-base stacking and exciton formation and dynamics in DNA oligomers.

scholarly journals Comparing Donor- and Acceptor-Originated Exciton Dynamics in Non-Fullerene Acceptor Blend Polymeric Systems

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1770
Author(s):  
Chan Im ◽  
Sang-Woong Kang ◽  
Jeong-Yoon Choi ◽  
Jongdeok An
Keyword(s):  
Flexible Electronics ◽  
Transient Absorption ◽  
Film Formation ◽  
Transient Absorption Spectroscopy ◽  
Excitation Wavelength ◽  
Polymeric Systems ◽  
Donor And Acceptor ◽  
Novel Material ◽  
Spectrally Resolved ◽  
Energy Strategies

Non-fullerene type acceptors (NFA) have gained attention owing to their spectral extension that enables efficient solar energy capturing. For instance, the solely NFA-mediated absorbing region contributes to the photovoltaic power conversion efficiency (PCE) as high as ~30%, in the case of the solar cells comprised of fluorinated materials, PBDB-T-2F and ITIC-4F. This implies that NFAs must be able to serve as electron donors, even though they are conventionally assigned as electron acceptors. Therefore, the pathways of NFA-originated excitons need to be explored by the spectrally resolved photovoltaic characters. Additionally, excitation wavelength dependent transient absorption spectroscopy (TAS) was performed to trace the nature of the NFA-originated excitons and polymeric donor-originated excitons separately. Unique origin-dependent decay behaviors of the blend system were found by successive comparing of those solutions and pristine films which showed a dramatic change upon film formation. With the obtained experimental results, including TAS, a possible model describing origin-dependent decay pathways was suggested in the framework of reaction kinetics. Finally, numerical simulations based on the suggested model were performed to verify the feasibility, achieving reasonable correlation with experimental observables. The results should provide deeper insights in to renewable energy strategies by using novel material classes that are compatible with flexible electronics.

scholarly journals Coherent Exciton Dynamics in Ensembles of Size-Dispersed CdSe Quantum Dot Dimers Probed via Ultrafast Spectroscopy: A Quantum Computational Study

2020 ◽  
Vol 10 (4) ◽  
pp. 1328 ◽  
Author(s):  
Hugo Gattuso ◽  
Barbara Fresch ◽  
Raphael D. Levine ◽  
Françoise Remacle
Keyword(s):  
Transient Absorption ◽  
Computational Study ◽  
Laser Pulses ◽  
Transient Absorption Spectroscopy ◽  
Basis Set ◽  
Charge Migration ◽  
Pump Probe ◽  
Electronic Response ◽  
Charge Transfer Excitons ◽  
Interdot Coupling

Interdot coherent excitonic dynamics in nanometric colloidal CdSe quantum dots (QD) dimers lead to interdot charge migration and energy transfer. We show by electronic quantum dynamical simulations that the interdot coherent response to ultrashort fs laser pulses can be characterized by pump-probe transient absorption spectroscopy in spite of the inevitable inherent size dispersion of colloidal QDs. The latter, leading to a broadening of the excitonic bands, induce accidental resonances that actually increase the efficiency of the interdot coupling. The optical electronic response is computed by solving the time-dependent Schrodinger equation including the interaction with the oscillating electric field of the pulses for an ensemble of dimers that differ by their size. The excitonic Hamiltonian of each dimer is parameterized by the QD size and interdot distance, using an effective mass approximation. Local and charge transfer excitons are included in the dimer basis set. By tailoring the QD size, the excitonic bands can be tuned to overlap and thus favor interdot coupling. Computed pump-probe transient absorption maps averaged over the ensemble show that the coherence of excitons in QD dimers that lead to interdot charge migration can survive size disorder and could be observed in fs pump-probe, four-wave mixing, or covariance spectroscopy.

scholarly journals Coupled valence carrier and core-exciton dynamics in WS2 probed by few-femtosecond extreme ultraviolet transient absorption spectroscopy

2021 ◽  
Vol 104 (6) ◽  
Author(s):  
Hung-Tzu Chang ◽  
Alexander Guggenmos ◽  
Christopher T. Chen ◽  
Juwon Oh ◽  
Romain Géneaux ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Transient Absorption ◽  
Extreme Ultraviolet ◽  
Transient Absorption Spectroscopy ◽  
Exciton Dynamics
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