On the Fluorescence Decay Curve of Anthracene

1967 ◽  
Vol 3 (2) ◽  
pp. 293-296
Author(s):  
G. J. Dienes
Keyword(s):  
Decay Curve ◽  
Fluorescence Decay ◽  
Fluorescence Decay Curve

scholarly journals Photoluminescence Characteristics of Sn2+ and Ce3+-Doped Cs2SnCl6 Double-Perovskite Crystals

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1501 ◽  
Author(s):  
Hongdan Zhang ◽  
Ludan Zhu ◽  
Jun Cheng ◽  
Long Chen ◽  
Chuanqi Liu ◽  
...  
Keyword(s):  
Decay Curve ◽  
Double Perovskite ◽  
Fluorescence Decay ◽  
Precipitation Method ◽  
Phase Precipitation ◽  
Fluorescence Decay Curve ◽  
Low Toxicity ◽  
Halide Perovskites ◽  
Lead Halide ◽  
Poor Stability

In recent years, all-inorganic lead-halide perovskites have received extensive attention due to their many advantages, but their poor stability and high toxicity are two major problems. In this paper, a low toxicity and stable Cs2SnCl6 double perovskite crystals were prepared by aqueous phase precipitation method using SnCl2 as precursor. By the XRD, ICP-AES, XPS, photoluminescence and absorption spectra, the fluorescence decay curve, the structure and photoluminescence characteristics of Ce3+-doped and undoped samples have been investigated in detail. The results show that the photoluminescence originates from defects. [ S n S n 4 + 2 + +VCl] defect complex in the crystal is formed by Sn2+ substituting Sn4+. The number of defects formed by Sn2+ in the crystal decreases with Ce3+ content increases. Within a certain number of defects, the crystal luminescence is enhanced with the number of [ S n S n 4 + 2 + +VCl] decreased. When Ce3+ is incorporated into the crystals, the defects of [ C e 3 + S n 4 + +VCl] and [ S n S n 4 + 2 + +VCl] were formed and the crystal show the strongest emission. This provides a route to enhance the photoluminescence of Cs2SnCl6 double perovskite crystals.

On the reliability of fluorescence decay data

1977 ◽  
Vol 30 (11) ◽  
pp. 2383 ◽  
Author(s):  
AL Hinde ◽  
BK Selinger ◽  
PR Nott
Keyword(s):  
Decay Curve ◽  
Fluorescence Decay ◽  
Decay Data ◽  
Accuracy And Precision

The confidence with which fluorescence decay data can be interpreted is dependent upon the accuracy and precision of these data. This dependence is especially critical when more than one exponential is involved in the decay.1,2 Unfortunately decay curve parameters have often been presented without any indication of either their accuracy or precision. An analysis is presented which suggests that the covariance ellipsoid is the most satisfactory statistic with which to define the precision.

scholarly journals Architecture of Polyglutamine-containing Fibrils from Time-resolved Fluorescence Decay

2014 ◽  
Vol 289 (39) ◽  
pp. 26817-26828 ◽  
Author(s):  
Christoph Röthlein ◽  
Markus S. Miettinen ◽  
Tejas Borwankar ◽  
Jörg Bürger ◽  
Thorsten Mielke ◽  
...  
Keyword(s):  
Fluorescence Decay ◽  
Time Resolved Fluorescence ◽  
Time Resolved

scholarly journals Fluorescence background discrimination by prebleaching.

1979 ◽  
Vol 27 (1) ◽  
pp. 96-101 ◽  
Author(s):  
T Hirschfeld
Keyword(s):  
Fluorescent Dyes ◽  
Fluorescence Decay ◽  
Free Form ◽  
Alternative Procedure ◽  
Background Fluorescence ◽  
Decay Lifetime ◽  
Fluorescent Molecules ◽  
Background Contrast

A number of electrooptical techniques are described that discriminate against background fluorescence in biologic staining, whether from sample background or unbound excess stain. These techniques are based on the fluorescent decay lifetime difference between bound stain and the sample background or between the bound stain its free form. The fluorescence decay lifetimes may be measured either directly or in a combination gated photometry scheme to substantially enhance the sample background contrast. An alternative procedure uses the photochemical bleaching of fluorescent dyes under intense exposure to time discriminate with higher selectivity, sensitivity and in a more convenient fashion between diverse fluorescent molecules.

Synthesis and Photophysical Properties of a Conformationally Flexible Mixed Porphyrin Star-Pentamer

2009 ◽  
Vol 62 (7) ◽  
pp. 692 ◽  
Author(s):  
Toby D. M. Bell ◽  
Sheshanath V. Bhosale ◽  
Kenneth P. Ghiggino ◽  
Steven J. Langford ◽  
Clint P. Woodward
Keyword(s):  
Energy Transfer ◽  
Photophysical Properties ◽  
Fluorescence Decay ◽  
High Yield ◽  
Free Base ◽  
Time Resolved ◽  
Zinc Porphyrin ◽  
Relative Contribution ◽  
Synthetic Strategy ◽  
Decay Times

The synthesis of a porphyrin star-pentamer bearing a free-base porphyrin core and four zinc(ii) metalloporphyrins, which are tethered by a conformationally flexible linker about the central porphyrin’s antipody, is described. The synthetic strategy is highlighted by the use of olefin cross metathesis to link the five chromophores together in a directed fashion in high yield. Photoexcitation into the Soret absorption band of the zinc porphyrin chromophores at 425 nm leads to a substantial enhancement of central free-base porphyrin fluorescence, indicating energy transfer from the photoexcited zinc porphyrin (outer periphery) to central free-base porphyrin. Time-resolved fluorescence decay profiles required three exponential decay components for satisfactory fitting. These are attributed to emission from the central free-base porphyrin and to two different rates of energy transfer from the zinc porphyrins to the free-base porphyrin. The faster of these decay components equates to an energy-transfer rate constant of 3.7 × 109 s–1 and an efficiency of 83%, whereas the other is essentially unquenched with respect to reported values for zinc porphyrin fluorescence decay times. The relative contribution of these two components to the initial fluorescence decay is ~3:2, similar to the 5:4 ratio of cis and trans geometric isomers present in the pentamer.

scholarly journals ZnSe Quantum Dots through a Facile one Pot Synthesis Process

2015 ◽  
Vol 34 ◽  
pp. 73-78
Author(s):  
Irtiqa Syed ◽  
Santa Chawla
Keyword(s):  
Quantum Dots ◽  
Band Gap ◽  
Quantum Confinement Effect ◽  
Hexagonal Phase ◽  
Fluorescence Decay ◽  
Synthesis Process ◽  
One Pot ◽  
One Pot Synthesis ◽  
Transmission Electron ◽  
Average Size

A novel one pot synthesis approach in oleic acid medium was employed to obtain monophasic ZnSe quantum dots (QD) of average size 3.7nm. The QDs were well crystalline in hexagonal phase as revealed by x-ray diffraction and high resolution transmission electron microscopy (HRTEM) studies. The ZnSe QDs exhibit sharp emission peak in the blue (465nm) with 385picosecond fluorescence decay time. The theoretical band gap corresponding to 3.7nm ZnSe QDs matched well with the measured 3.11eV band gap of synthesized QDs which thus showed quantum confinement effect.

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