Control of the photoluminescence in Ba0.97Y2Si3O10:Eu2+ phosphors via the intensification effect of the second luminescence centre

2018 ◽  
Vol 5 (9) ◽  
pp. 2111-2122 ◽  
Author(s):  
Haoran Li ◽  
Yujun Liang ◽  
Yingli Zhu ◽  
Shiqi Liu ◽  
Jiahui Chen ◽  
...  
Keyword(s):  
Emission Spectra ◽  
Emission Peak ◽  
Luminescence Centre

A method is reported that broadens the FWHMs of the emission spectra of Ba0.97Y2Si3O10:0.03Eu2+ by intensifying the second emission peak.

Influence of the Dispersion of the Size of the Si Nanocrystals on their Emission Spectra

1994 ◽  
Vol 358 ◽  
Author(s):  
J. B. Khurgin ◽  
E. W. Forsythe ◽  
S. I. Kim ◽  
B. S. Sywe ◽  
B. A. Khan ◽  
...  
Keyword(s):  
Systematic Study ◽  
Quantum Confinement ◽  
Emission Spectra ◽  
Emission Peak ◽  
Nanocrystal Size ◽  
Pl Spectra ◽  
Si Nanocrystals ◽  
Average Size ◽  
Size Dispersion ◽  
Confinement Model

ABSTRACTA systematic study of the PL spectra of Si quantum nanocrystals in the SiO2 matrix has been performed. The results have been fitted to a quantum-confinement model that includes the nanocrystal size dispersion rather than a specific size of the nanocrystal. This serves as a strong confirmation of the confinement-induced nature of the PL. It has been shown that if the dispersion is taken into account, the position of the emission peak as well as the PL width can always be correlated with the average size of the nanocrystal.

Photoluminescence and Scintillation Properties of Pb2+ Based Quantum Dots in CsCI Host Crystal

1994 ◽  
Vol 348 ◽  
Author(s):  
M. Nikl ◽  
K. Nitsch ◽  
I. Dafinei ◽  
P. Lecoq ◽  
G.P. Pazzi ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Steady State ◽  
Room Temperature ◽  
Emission Spectra ◽  
Emission Peak ◽  
Kinetic Properties ◽  
Host Crystal ◽  
Exponential Behavior ◽  
Decay Times ◽  
Single Exponential

ABSTRACTThe spectral and kinetic properties of photoluminescence of Pb2+ aggregated phase in CsC1 host, together with scintillation characteristics of CsCI:Pb crystals, are reported in the 10 - 300 K temperature range. Absorption, steady-state excitation and emission spectra of Pb2+ phase in CsCI host are similar to those of CsPbCl3 bulk crystal (emission peak at 419 nm at 10 K). The decay of the 421 nm luminescence of the Pb2+ phase in CsCl shows single exponential behavior with extremely short decay time of 40 ps at 421 nm and 10 K,which is considerably shorter than the decay times found in the decay of CsPbCl3 bulk emission (0.45, 2.8 and 12 ns at 418 nm and 10 K). In the scintillation decay of CsCI:Pb, two components with 0.95-1 ns and 2-3 ns decay times were found and no slower component is present at room temperature.

scholarly journals Detection of polystyrene nanoplastics in biological tissues with a fluorescent molecular rotor probe

2019 ◽  
Author(s):  
François Gagné
Keyword(s):  
Limit Of Detection ◽  
Environmental Concern ◽  
Emission Spectra ◽  
Biological Tissues ◽  
Emission Peak ◽  
Quantitative Detection ◽  
Molecular Rotor ◽  
Theoretical Limit ◽  
Tissue Extracts ◽  
Spectrofluorometric Method

The release of nanoplastics (NPs) from the weathering and degradation of plastics is an important environmental concern. Given their small sizes and their invasiveness in cells, methods for the detection of NPs in biological tissues are urgently needed. A simple fluorescence-based methodology for the detection of polystyrene NPs in biological tissues is proposed. The commercially available molecular rotor probe 9- (dicyanovinyl)-julolidine (DCVJ) has the properties to detect changes in hydrophobicity and microviscosity and was used to detect NPs. Increasing concentrations of 50 and 100 nm NPs in water and in tissue extracts were mixed with the DCVJ probe and the emission spectra determined between 480-800 nm at 450 nm excitation. The data revealed that NPs induces a second emission peak at 620 nm that differed from the normal spectra of the biological extract at 500 nm. A significant linear relationship was obtained for NPs of both sizes (r=0.98; P<0.001) with a theoretical limit of detection of 65 ng/mL. A simple and rapid microplate spectrofluorometric method for the semi-quantitative detection of polystyrene NPs in biological tissues is thus presented.

Study on a New Coumarin Derivative as Fluorescent Probe for Hg2+ Ions

2014 ◽  
Vol 904 ◽  
pp. 99-102
Author(s):  
Hong Qi Li ◽  
Zhen Chen ◽  
Hao Chen ◽  
Jia Wei Zhang ◽  
Yan Tai Chen ◽  
...  
Keyword(s):  
Metal Ions ◽  
Fluorescent Probe ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Coumarin Derivative ◽  
Emission Peak ◽  
Fluorescence Emission Spectra ◽  
Maximum Emission ◽  
H Nmr ◽  
C Nmr

A new coumarin derivative L was synthesized and characterized by1H NMR,13C NMR, IR and mass spectrum. UV-Vis and fluorescence emission spectra of L without or with different anions (NO2, F, Cl, HSO3, HSO4, AcO or NO3) or metal ions were measured, which showed while addition of anions or metal ions Mg2+, Zn2+, Ca2+, Cu2+, Ni2+, Co2+, Fe3+or Al3+led to decrease in intensity of the maximum emission peak at about 480 nm, addition of Hg2+ions caused increase in intensity of the maximum emission peak, suggesting that L may act as a fluorescent probe for detection of Hg2+ions.

Photoluminescence of GdVO4:Eu3+, Al 3+ Phosphors under VUV Excitation

2012 ◽  
Vol 18-19 ◽  
pp. 257-263 ◽  
Author(s):  
K. Park ◽  
M.H. Heo ◽  
Y. Kim ◽  
J.Y. Kim
Keyword(s):  
High Purity ◽  
Emission Intensity ◽  
Emission Spectra ◽  
Local Symmetry ◽  
Emission Peak ◽  
Photoluminescence Properties ◽  
High Quality ◽  
Red Emission ◽  
Crystallite Sizes ◽  
The Difference

The microstructure and photoluminescence properties of Gd0.94-xAlxEu0.06VO4 (0≤x≤0.04) phosphors with various Al3+ contents were investigated. The phosphors showed a nanocrystalline nature and a high-quality powder characteristic. The crystallite sizes of the phosphors were calculated to be 46-48 nm. The annealed Gd0.94-xAlxEu0.06VO4 phosphors crystallized in the tetragonal structure. In the emission spectra, several emission peaks were observed over the measured wavelength range (500-750 nm), which were caused by the difference in the transitions of Eu3+ ions, depending on the local symmetry (5D0 → 7Fj, j = 1, 2, 3, and 4). The strongest emission peak was located at 619 nm, providing a high-purity red emission. The doped Al3+ yielded significantly enhanced the emission intensity. The most intense high-purity red emission was obtained for Gd0.93Al0.01Eu0.06VO4.

Luminescence Properties of Rare Earth Activated Aluminates Based Phosphor

2016 ◽  
Vol 28 ◽  
pp. 115-119
Author(s):  
Anupam Selot ◽  
Kapil Dev ◽  
Mahendra Aynyas ◽  
Sanjay Bhatt
Keyword(s):  
Emission Spectra ◽  
Combustion Method ◽  
Emission Peak ◽  
Prepared Phosphor ◽  
Ultraviolet Region ◽  
X Ray Diffraction ◽  
Quenching Mechanism ◽  
Strong Emission ◽  
X Ray ◽  
Peak Intensity

A blue emitting phosphor BaAl2O4 doped with Gd3+ were prepared by combustion method at 5000C. The prepared phosphor were investigated by X-ray Diffraction to determine the crystalinity. Photoluminescence emission spectra centred at 369 nm under ultraviolet region, which corresponds to 5d-4f transition of Gd3+ ions. The PL spectra showed strong emission peak intensity and extending to 400nm to 453nm.Concentration quenching mechanism were occurred about 1mol% of Gd3+ ion. The results revealed that phosphor prepared by using combustion method can be useful WLED.

scholarly journals Outstanding Photoluminescence in Pr3+-Doped Perovskite Ceramics

Micromachines ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 419
Author(s):  
Jiameng Zhang ◽  
Yanan Hao ◽  
Meihua Bi ◽  
Guoyan Dong ◽  
Xiaoming Liu ◽  
...  
Keyword(s):  
Emission Spectra ◽  
Green Emission ◽  
Emission Peak ◽  
Ferroelectric Ceramics ◽  
X Ray Diffraction ◽  
Green Band ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Application Range ◽  
Pl Emission

Ba (Zr0.2Ti0.8) O3-50% (Ba0.7Ca0.3) TiO3 (BZT-0.5BCT) ceramics with different doping contents of Pr3+ were prepared by the conventional solid-state reaction. The phase structure and crystallinity of the fabricated ceramics were investigated by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. Photoluminescence (PL) emission spectra were measured to analyze the PL characteristics. The strong intensities of a green band at 489 nm and a red band at 610 nm were observed. The maximum emission intensity of the PL spectrum was achieved in the BZT-0.5BCT ceramic with 0.2% mol of Pr3+ ions. Furthermore, the PL spectra of BZT-0.5BCT ceramics were found to be sensitive to polarization of the ferroelectric ceramics. Compared with the unpoled ceramics, the green emission increased about 42% and a new emission peak at 430 nm appeared for the poled ceramics. With excellent intrinsic ferroelectricity and an enhanced PL property, such material has potential to realize multifunctionality in a wide application range.

Synthesis and Optical Properties of a Novel Oligobipyridine

2001 ◽  
Vol 665 ◽  
Author(s):  
Y. J. Fu ◽  
T.K.S. Wong ◽  
H.X. Zhang ◽  
G. M. Wang ◽  
X. Hu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Conjugated Polymers ◽  
Double Layer ◽  
Single Layer ◽  
Emission Spectra ◽  
Amorphous Film ◽  
Emission Peak ◽  
Conjugation Length ◽  
Emission Color ◽  
Film State

ABSTRACTIn this paper, 5,5' –bis [ 4'– methyl- ( 2,2'– bipyridin– 4- yl)- ethyl ]- 2,2'– bipyridine (BMBPYBPY), a partially conjugated derivative of oligobipyridine, has been synthesized and found to show strong photoluminescence (PL). Compared with the pyridine-based conjugated polymers, the shortened conjugation length shifts the emission color from green to violet-blue. The effects of morphology on its PL properties have been studied. From its as-precipitated powder state, an emission peak at 418 nm can be observed. However the emission spectra from its diffused states such as doped in KBr, or dissolved in CHCl3, as well as from its amorphous film state fabricated by vacuum evaporation are more complex. Also carried out are preliminary electroluminescent studies. Single layer devices ITO/BMBPYBPY/Al do not emit although current can be observed prominently. Double layer devices ITO/TPD/ BMBPYBPY/Al show emissions both from TPD and BMBPYBPY.

A Novel Phenomenon of Energy Transfer in Cd1-XZnxSiO3 : 0.01 Mn2+ Phosphor

2012 ◽  
Vol 549 ◽  
pp. 487-490 ◽  
Author(s):  
Xin Mu Zhou ◽  
Yong Xiu Li
Keyword(s):  
Energy Transfer ◽  
Ultraviolet Light ◽  
Sol Gel ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Emission Peak ◽  
Red Shift ◽  
Excitation Spectra ◽  
Gel Method ◽  
Sol Gel Method

Cd1-xZnxSiO3:0.01 Mn2+phosphor was synthesized by sol-gel method. It was characterized by excitation, emission spectra and XRD. The luminescent properties show the phenomenon of energy transfer from the tetrahedral coordinated Mn2+ion to the octahedral coordinated Mn2+ion after exciting by ultraviolet light, which boost the performance of the phosphor. With the increasing of Zn2+in Cd1-xZnxSiO3:0.01 Mn2+phosphor, it was observed the excitation spectra broadened and a red shift in the emission spectra, which emission peak moved from 580nm to 589nm.

Effect of the Co-Substitution of Ca2+ and Si4+ on the Structure and Luminescence Properties of Y3Al5O12: Ce3+

2011 ◽  
Vol 233-235 ◽  
pp. 1844-1849 ◽  
Author(s):  
Zhong Fei Mu ◽  
Yi Hua Hu ◽  
Yin Hai Wang ◽  
Li Chen ◽  
Xiao Juan Wang
Keyword(s):  
Solid State ◽  
Cell Parameter ◽  
Emission Spectra ◽  
Blue Shift ◽  
Emission Peak ◽  
Solid State Reactions ◽  
Garnet Structure ◽  
Co Substitution ◽  
Xrd Patterns ◽  
Substitution Content

A series of phosphors with the composition of Y2.95-xCaxAl5-xSixO12: Ce3+0.05 (x=0, 0.15, 0.30, 0.45, 0.60, 0.75) were synthesized with conventional solid state reactions. The results of XRD patterns show that in a certain extent, the co-substitution of Ca2+ and Si4+ does not change the garnet structure of samples, while results in the shrink of crystal lattice(The cell parameter of phosphors decreases with the increment of co-substitution content monotonically. The former is in linear with the latter). The measurement of the excitation and emission spectra shows that the co-substitution of Ca2+ and Si4+ make the emission peak move to short wavelength. The amount of blue shift is also in linear with the co-substitution content.

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