Temperature dependence of the fluorescence lifetime and quantum yield of pseudoisocyanine monomers

1986 ◽  
Vol 130 (5) ◽  
pp. 426-431 ◽  
Author(s):  
Hans-Peter Dorn ◽  
Alexander Müller
Author(s):  
Peter P. Knox ◽  
Vladimir V. Gorokhov ◽  
Boris N. Korvatovsky ◽  
Nadezhda P. Grishanova ◽  
Sergey N. Goryachev ◽  
...  

2021 ◽  
Vol 498 (1) ◽  
pp. 170-176
Author(s):  
V. V. Gorokhov ◽  
B. N. Korvatovsky ◽  
P. P. Knox ◽  
N. P. Grishanova ◽  
S. N. Goryachev ◽  
...  

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5394
Author(s):  
Mani Outis ◽  
João Paulo Leal ◽  
Maria Helena Casimiro ◽  
Bernardo Monteiro ◽  
Cláudia Cristina Lage Pereira

Here we discuss the influence of two different cations on the emissive properties of the highly emissive [Eu(fod)4]− anion. The studied Eu(III) salts were [C16Pyr][Eu(fod)4] (1), and the previously reported [Chol][Eu(fod)4]. C16Pyr stands for N-cetylpyridinium, Chol for cholinium and fod for 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyloctane-4,6-dionate. 1 is classified as ionic liquid, with melting point close to 60 °C, and presented a luminescence quantum yield of (ϕ) 100%. Ultrabright emissive photopolymers were obtained for the first time using polysulfone as the host matrix. The films were prepared with incorporation of 10% (w/w) of 1 and [Chol][Eu(fod)4] in the polymeric matrix, which improved its thermal stability. Additionally, the luminescence of CholEu(fod)4/PSU presented a strong temperature dependence with a ratiometric thermal behavior.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Avry Shirakov ◽  
Zeev Burshtein ◽  
Yehoshua Shimony ◽  
Eugene Frumker ◽  
Amiel A. Ishaaya

AbstractWe have measured the fluorescence quantum efficiency in Ti3+:sapphire single crystals between 150 K and 550 K. Using literature-given effective fluorescence lifetime temperature dependence, we show that the zero temperature radiative lifetime is (4.44 ± 0.04) μs, compared to the 3.85 μs of the fluorescence lifetime. Fluorescence lifetime thermal shortening resolves into two parallel effects: radiative lifetime shortening, and non-radiative transition rate enhancement. The first is due to thermally enhanced occupation of a ΔE = 1,700 cm−1 higher (top) electronic state of the upper multiplet, exhibiting a transition oscillator strength of f = 0.62, compared to only 0.013 of the bottom electronic state of the same multiplet. The non-radiative rate relates to multi-phonon decay transitions stimulated by the thermal phonon occupation. Thermal enhancement of the configuration potential anharmonicity is also observed. An empiric expression for the figure-of-anharmonicity temperature dependence is given as $$\hat{{\bf{H}}}$$Hˆ (T) = $$\hat{{\bf{H}}}$$Hˆ (0)(1 + β exp(−ℏωco /kBT )), where $$\hat{{\bf{H}}}$$Hˆ (0) = 0.276, β = 5.2, ℏωco = 908 cm−1, and kB is the Boltzmann constant.


Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 343
Author(s):  
Pavlína Andrýsková ◽  
Karolína Machalová Šišková ◽  
Šárka Michetschlägerová ◽  
Klára Jiráková ◽  
Martin Kubala ◽  
...  

Fluorescent gold nanoclusters (AuNCs) are envisaged as a novel type of fluorophores. This work reports on the first comparative study investigating the effect of presence/absence/abundance of fatty acids (namely palmitic acid, PA) or other substances (like glycoproteins and globulins) in the protein (bovine serum albumin, BSA) on synthesis and properties of the final AuNCs. The most popular template (BSA) and microwave (MW)-assisted synthesis of AuNCs have been intentionally chosen. Our results clearly demonstrate that the fluorescent characteristics (i.e., fluorescence lifetime and quantum yield) are affected by the fatty acids and/or other substances. Importantly, the as-prepared AuNCs are biocompatible, as determined by Alamar Blue assay performed on Hep G2 cell line.


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