Excited-State Vibrational Coherence in Perylene Bisimide Probed by Femtosecond Broadband Pump–Probe Spectroscopy

2015 ◽  
Vol 119 (24) ◽  
pp. 6275-6282 ◽  
Author(s):  
Minjung Son ◽  
Kyu Hyung Park ◽  
Min-Chul Yoon ◽  
Pyosang Kim ◽  
Dongho Kim
2010 ◽  
Vol 1270 ◽  
Author(s):  
Giulia Grancini ◽  
Dario Polli ◽  
Jenny Clark ◽  
Tersilla Virgili ◽  
Giulio Cerullo ◽  
...  

AbstractWe introduce a novel instrument combining femtosecond pump-probe spectroscopy and confocal microscopy for spatio-temporal imaging of excited-state dynamics of phase-separated polymer blends. Phenomena occurring at interfaces between different materials are crucial for optimizing the device performances, but are poorly understood due to the variety of possible electronic states and processes involved and to their complicated dynamics. Our instrument (with 200-fs temporal resolution and 300-nm spatial resolution) provides new insights into the properties of polymer blends, revealing spatially variable photo-relaxation paths and dynamics and highlighting a peculiar behaviour at the interface between the phase-separated domains.


2019 ◽  
Vol 123 (6) ◽  
pp. 3868-3875 ◽  
Author(s):  
Brenna R. Walsh ◽  
Colin Sonnichsen ◽  
Timothy G. Mack ◽  
Jonathan I. Saari ◽  
Michael M. Krause ◽  
...  

2020 ◽  
Author(s):  
Jacob Garcia ◽  
ryan shaffer ◽  
Scott Sayres

<div><p>Neutral iron oxide clusters (Fe<sub>n</sub>O<sub>m</sub>, n,m ≤ 16) are produced in a laser vaporization source using O<sub>2</sub>gas seeded in He. The neutral clusters are ionized with a sequence of femtosecond laser pulses and detected using time-of-flight mass spectrometry. Small clusters are confirmed to be most prominant in the stoichiometric (n = m) distribution, with m = n + 1 clusters observed above n = 4. Pump-probe spectroscopy is employed to study the dynamics of an electron transfer from an oxygen orbital to an iron nonbonding orbital of iron oxide clusters that is driven by absorption of a 400 nm photon. A bifurcation of the initial wavepacket occurs, where a femtosecond component is attributed to electron relaxation assisted through internuclear vibrational relaxation, and a slow relaxation shows the formation of a bound excited state. The lifetime and relative ratio of the two pathways depends on both the cluster size and iron oxidation state. The femtosecond lifetime decreases with increased cluster size until a saturation timescale is achieved at n > 5. The relative population of the long-lived excited state decreases with cluster size and suggests that the excited electron remains on the Fe atom for > 20 ps. </p></div>


2020 ◽  
Author(s):  
Jacob Garcia ◽  
ryan shaffer ◽  
Scott Sayres

<div><p>Neutral iron oxide clusters (Fe<sub>n</sub>O<sub>m</sub>, n,m ≤ 16) are produced in a laser vaporization source using O<sub>2</sub>gas seeded in He. The neutral clusters are ionized with a sequence of femtosecond laser pulses and detected using time-of-flight mass spectrometry. Small clusters are confirmed to be most prominant in the stoichiometric (n = m) distribution, with m = n + 1 clusters observed above n = 4. Pump-probe spectroscopy is employed to study the dynamics of an electron transfer from an oxygen orbital to an iron nonbonding orbital of iron oxide clusters that is driven by absorption of a 400 nm photon. A bifurcation of the initial wavepacket occurs, where a femtosecond component is attributed to electron relaxation assisted through internuclear vibrational relaxation, and a slow relaxation shows the formation of a bound excited state. The lifetime and relative ratio of the two pathways depends on both the cluster size and iron oxidation state. The femtosecond lifetime decreases with increased cluster size until a saturation timescale is achieved at n > 5. The relative population of the long-lived excited state decreases with cluster size and suggests that the excited electron remains on the Fe atom for > 20 ps. </p></div>


2018 ◽  
Vol 20 (19) ◽  
pp. 13400-13411 ◽  
Author(s):  
Dipak Kumar Das ◽  
Krishnandu Makhal ◽  
Debabrata Goswami

Using a degenerate pump probe technique at 800 nm, Ground State Vibrational Coherence (GSVC) of a cyanine dye (IR780) is explored in various solvents.


RSC Advances ◽  
2015 ◽  
Vol 5 (27) ◽  
pp. 20810-20817 ◽  
Author(s):  
Narra Vamsi Krishna ◽  
Varun Kumar Singh ◽  
Debasis Swain ◽  
Soma Venugopal Rao ◽  
Lingamallu Giribabu

Synthesis and characterisation of a Zn phthalocyanine substituted with bis(3,5-trifluoromethyl)phenyl groups at peripheral positions by absorption, fluorescence and electrochemical techniques. Excited state dynamics were investigated by fs degenerate pump–probe spectroscopy.


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