Temperature-dependent reorientation dynamics of laser dyes in alkane and alcohol solvents

2013 ◽  
Vol 91 (9) ◽  
pp. 677-681 ◽  
Author(s):  
Y.F. Nadaf ◽  
C.G. Renuka ◽  
U.S. Raikar
Keyword(s):  
Relaxation Times ◽  
Laser Dyes ◽  
Temperature Dependent ◽  
Fluorescence Depolarization ◽  
Time Resolved ◽  
Structural Differences ◽  
Reorientation Time ◽  
Reorientation Dynamics ◽  
Alcohol Solvents ◽  
Coumarin 6

The rotational dynamics of similar sized coumarin 6 (C6), coumarin 7 (C7), and coumarin 30 (C30) laser dyes has been studied in alkane and alcohol solvents using steady-state and time-resolved fluorescence depolarization methods. The estimated rotational reorientation times of these probes are observed to vary linearly as a function of viscosity over the range of temperatures studied. It is found that the rotational reorientation time measurements of these molecules in alcohol and alkane typically have relaxation times on the order of picoseconds. The rotational reorientation times of the C7 molecule are greater than those of the C6 and C30 molecules. It was observed that C7 rotates faster in both the solvents than C6 and C30, indicating that the effects of the medium and structural differences of molecules lead to slower rotation.

Analysis of rotational diffusion of coumarin laser dyes

2015 ◽  
Vol 93 (1) ◽  
pp. 3-6 ◽  
Author(s):  
Y.F. Nadaf ◽  
C.G. Renuka
Keyword(s):  
Rotational Diffusion ◽  
Relaxation Times ◽  
Laser Dyes ◽  
Fluorescence Depolarization ◽  
Time Resolved ◽  
Diffusion Analysis ◽  
Alkane Solvents ◽  
Alcohol Solvents ◽  
Coumarin Laser Dyes ◽  
Coumarin 6

Rotational diffusion analysis of two laser dyes, coumarin 6 and coumarin 30, has been studied in alkane and alcohol solvents using steady-state and time-resolved fluorescence depolarization methods. The rotational diffusion times of these probes vary linearly as a function of viscosity over the range of temperature studied. It is observed that the rotational diffusion time measurements of molecules in alcohol and alkane have relaxation times typically on the order of picoseconds, though they are greater in alcohol than in alkane solvents. However, it was observed that coumarins rotate faster in n-hexane and n-heptane than in n-propanol and n-butanol solvents, and the observed results are discussed in the last section.

scholarly journals Solvation Dynamics Studied by Picosecond Fluorescence: Microscopic Reorientation and Longitudinal Relaxation of the Solvent

1990 ◽  
Vol 10 (5-6) ◽  
pp. 413-429 ◽  
Author(s):  
A. Declémy ◽  
C. Rulliére ◽  
Ph. Kottis
Keyword(s):  
Time Dependent ◽  
Solvation Dynamics ◽  
Specific Interactions ◽  
Longitudinal Relaxation Time ◽  
Time Resolved ◽  
Different Temperatures ◽  
Reorientation Time ◽  
Longitudinal Relaxation ◽  
Solvent Molecules ◽  
Alcohol Solvents

The dynamics of the Time-Dependent Fluorescence Shift (TDFS) of a rigid polar excited probe dissolved in alcohol solvents at different temperatures have been studied by picosecond time-resolved spectroscopy. The results are compared to previously published results on well characterized polar systems. These results show that solvation dynamics in such systems are strongly scaled by the microscopic (singleparticle) reorientation time τM of the solvent molecules and/or by the (macroscopic) longitudinal relaxation time τL of the solvent. The key point governing this scaling is the relative interaction between the solvent molecules and the probe compared to the interaction between the solvent molecules. It is also shown that specific interactions, such as hydrogen bonded-complex formation, may play an important role.

scholarly journals Carrier Dynamic Investigations of AlGaInAs Quantum Well Revealed by Temperature-Dependent Time-Resolved Photoluminescence

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4227
Author(s):  
Yue Song ◽  
Yongyi Chen ◽  
Ligong Zhang ◽  
Yugang Zeng ◽  
Cheng Qiu ◽  
...  
Keyword(s):  
Quantum Well ◽  
Decay Channel ◽  
Relaxation Times ◽  
Emission Spectra ◽  
Nonradiative Recombination ◽  
Temperature Dependent ◽  
Time Resolved ◽  
Carrier Relaxation ◽  
Carrier Dynamic ◽  
Time Resolved Photoluminescence

AlGaInAs quantum well (QW) lasers have great potential in the application fields of optical communications and eye-safety lidars, owing to the advantages of good gain performance. A large amount of experimental evidence indicated that carrier dynamic affects the resonant frequency and modulation response performance of QW lasers. However, the mechanism of carrier dynamic in AlGaInAs QW structure is still ambiguous for complicated artificial multilayers. In this paper, the carrier dynamic of AlGaInAs QW structure was investigated by temperature-dependent time-resolved photoluminescence (TRPL) in the range of 14 to 300 K. Two relaxation times (a fast component and a slow one) have a major impact on the PL emission spectra of the AlGaInAs QW below 200 K. The carriers prefer a fast decay channel in the low temperature regime, whereas the slow one a higher temperature. An unconventional temperature dependence of carrier relaxation is observed in both decay processes. The carriers’ lifetime decreases with the temperature increasing till 45 K and then increases with temperature up to 250 K. It is quite different from that in the bulk semiconductor. The mechanism of temperature-dependent carrier relaxation at temperatures above 45 K is a combination of dark state occupation and a nonradiative recombination process.

Temperature Dependent Kinetics of the OH/HO2/O3Chain Reaction by Time-Resolved IR Laser Absorption Spectroscopy

2000 ◽  
Vol 104 (17) ◽  
pp. 3964-3973 ◽  
Author(s):  
Sergey A. Nizkorodov ◽  
Warren W. Harper ◽  
Bradley W. Blackmon ◽  
David J. Nesbitt
Keyword(s):  
Absorption Spectroscopy ◽  
Laser Absorption Spectroscopy ◽  
Temperature Dependent ◽  
Time Resolved ◽  
Laser Absorption ◽  
Ir Laser ◽  
Kinetics Of

scholarly journals The thermal stability of FAPbBr3 nanocrystals from temperature-dependent photoluminescence and first-principles calculations

RSC Advances ◽  
2020 ◽  
Vol 10 (72) ◽  
pp. 44373-44381
Author(s):  
Xiaozhe Wang ◽  
Qi Wang ◽  
Zhijun Chai ◽  
Wenzhi Wu
Keyword(s):  
First Principles ◽  
First Principle ◽  
First Principles Calculations ◽  
Temperature Dependent ◽  
Time Resolved ◽  
First Principle Calculations ◽  
Steady State Time ◽  
Time Resolved Photoluminescence ◽  
Thermal Stability Of ◽  
Temperature Dependent Photoluminescence

The thermal properties of FAPbBr3 perovskite nanocrystals (PNCs) is investigated by use of temperature-dependent steady-state/time-resolved photoluminescence and first-principle calculations.

scholarly journals Evidence for a Novel Mechanism of Time-Resolved Flavin Fluorescence Depolarization in Glutathione Reductase

2004 ◽  
Vol 87 (4) ◽  
pp. 2577-2586 ◽  
Author(s):  
Petra A.W. van den Berg ◽  
Arie van Hoek ◽  
Antonie J.W.G. Visser
Keyword(s):  
Glutathione Reductase ◽  
Fluorescence Depolarization ◽  
Time Resolved
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