Oscillation in Excited State Lifetimes with Size of Sub-nanometer Neutral (TiO2)n Clusters Observed with Ultrafast Pump–Probe Spectroscopy

2021 ◽  
Vol 12 (16) ◽  
pp. 4098-4103
Author(s):  
Jacob M. Garcia ◽  
Lauren F. Heald ◽  
Ryan E. Shaffer ◽  
Scott G. Sayres
Keyword(s):  
Excited State ◽  
Pump Probe ◽  
Excited State Lifetimes ◽  
Probe Spectroscopy

Investigation of Local Dynamics on the Sub-micron Scale in Organic Blends Using an Ultrafast Confocal Microscope

2010 ◽  
Vol 1270 ◽  
Author(s):  
Giulia Grancini ◽  
Dario Polli ◽  
Jenny Clark ◽  
Tersilla Virgili ◽  
Giulio Cerullo ◽  
...  
Keyword(s):  
Excited State ◽  
Confocal Microscopy ◽  
Polymer Blends ◽  
Spatial Resolution ◽  
Temporal Resolution ◽  
Electronic States ◽  
Pump Probe ◽  
Peculiar Behaviour ◽  
Spatio Temporal ◽  
Probe Spectroscopy

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.

Excited State Phononic Processes in Semiconductor Nanocrystals Revealed by Excitonic State-Resolved Pump/Probe Spectroscopy

2019 ◽  
Vol 123 (6) ◽  
pp. 3868-3875 ◽  
Author(s):  
Brenna R. Walsh ◽  
Colin Sonnichsen ◽  
Timothy G. Mack ◽  
Jonathan I. Saari ◽  
Michael M. Krause ◽  
...  
Keyword(s):  
Excited State ◽  
Semiconductor Nanocrystals ◽  
Pump Probe ◽  
Excitonic State ◽  
Probe Spectroscopy

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
Keyword(s):  
Excited State ◽  
Pump Probe ◽  
Vibrational Coherence ◽  
Perylene Bisimide ◽  
Probe Spectroscopy

scholarly journals Oscillation in Excited State Lifetimes with Size of Sub-Nanometer Neutral (TiO2)n Clusters Observed with Ultrafast Pump-Probe Spectroscopy

2021 ◽  
Author(s):  
Jacob Garcia ◽  
Lauren Heald ◽  
ryan shaffer ◽  
Scott Sayres
Keyword(s):  
Excited State ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Laser Vaporization ◽  
Carrier Recombination ◽  
Electron Hole Pair ◽  
Excited State Lifetimes ◽  
Probe Spectroscopy

<div>Neutral titanium oxide clusters of up to 1 nm in diameter (TiO<sub>2</sub>)<sub>n</sub>, with n < 10, are produced in a laser vaporization source and subsequently ionized by a sequence of femtosecond laser pulses. Using 400 nm pump, 800 nm probe lasers, the excited state lifetimes of neutral (TiO<sub>2</sub>)<sub>n</sub> clusters are measured. All clusters exhibit a rapid relaxation lifetime of ~30 fs, followed by a sub-picosecond lifetime that we attribute to carrier recombination. The excited state lifetimes oscillate with size, with even numbered clusters possessing longer lifetimes. Density functional theory calculations show the excited state lifetimes are correlated with electron-hole pair localization or polaron-like formation in the excited states of neutral clusters. Thus, structural rigidity is suggested as a feature for extending excited state lifetimes in titania materials.</div>

scholarly journals Ultrafast Pump-Probe Spectroscopy of Finite-Sized Neutral Iron Oxide Clusters

2020 ◽  
Author(s):  
Jacob Garcia ◽  
ryan shaffer ◽  
Scott Sayres
Keyword(s):  
Excited State ◽  
Iron Oxide ◽  
Cluster Size ◽  
Iron Oxidation ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Laser Vaporization ◽  
Relative Population ◽  
Pump Probe ◽  
Probe Spectroscopy

<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>

scholarly journals Ultrafast Pump-Probe Spectroscopy of Finite-Sized Neutral Iron Oxide Clusters

2020 ◽  
Author(s):  
Jacob Garcia ◽  
ryan shaffer ◽  
Scott Sayres
Keyword(s):  
Excited State ◽  
Iron Oxide ◽  
Cluster Size ◽  
Iron Oxidation ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Laser Vaporization ◽  
Relative Population ◽  
Pump Probe ◽  
Probe Spectroscopy

<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>

Optical, electrochemical, third order nonlinear optical, and excited state dynamics studies of bis(3,5-trifluoromethyl)phenyl-zinc phthalocyanine

RSC Advances ◽  
2015 ◽  
Vol 5 (27) ◽  
pp. 20810-20817 ◽  
Author(s):  
Narra Vamsi Krishna ◽  
Varun Kumar Singh ◽  
Debasis Swain ◽  
Soma Venugopal Rao ◽  
Lingamallu Giribabu
Keyword(s):  
Excited State ◽  
Nonlinear Optical ◽  
Electrochemical Techniques ◽  
Zinc Phthalocyanine ◽  
Third Order ◽  
Pump Probe ◽  
Excited State Dynamics ◽  
Probe Spectroscopy

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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