scholarly journals Real-time RGB color-tunable upconversion luminescence using a single excitation wavelength

2021 ◽  
Author(s):  
Li Xu ◽  
Yu Liu ◽  
Ziwen Zhou ◽  
Danyang Ning ◽  
Jing Ren ◽  
...  
Keyword(s):  
Real Time ◽  
Continuous Wave ◽  
Upconversion Luminescence ◽  
Lanthanide Ions ◽  
Excitation Wavelength ◽  
Core Shell ◽  
Primary Color ◽  
The Core ◽  
Color Tunable ◽  
Excitation Laser

Abstract Real-time color-tunable upconversion luminescence of lanthanide ions has recently attracted increasing attention. To date, at least two different excitation wavelengths are required to obtain tunable upconversion colors containing the three-primary-color components (Red-Green-Blue). In this work, for the first time, we demonstrate that it is possible achieving tunable three-primary-color upconversion luminescence using a single excitation wavelength, on the basis of the photon-order dependent uponversion nature. A core-shell-shell nanocrystal was synthesized, with rational designed compositions of Er/Yb and Tm/Yb in the core and the outermost shell, respectively, responsible for the green/red and blue emissions. By increasing the power density of the 980 nm continuous-wave excitation laser, the color of the emitted luminescence of the core-shell-shell nanocrystal evolved as green → red → blue, corresponding to 2 → 3 → 4-photons involved in the upconversion process.

Optical Temperature Sensing of Core-Shell Structured NaYF4:Yb3+, Er3+@NaYF4 Nanocrystals with Different Shell Thickness

2015 ◽  
Vol 738-739 ◽  
pp. 27-30
Author(s):  
Dong Dong Li ◽  
Qi Yue Shao ◽  
Yan Dong ◽  
Jian Qing Jiang
Keyword(s):  
Shell Thickness ◽  
Thermal Sensitivity ◽  
Upconversion Luminescence ◽  
Temperature Sensing ◽  
Upconversion Nanoparticles ◽  
Core Shell ◽  
Sensing Properties ◽  
The Core ◽  
Β Phase ◽  
Biomedical Fields

Hexagonal (β)-phase NaYF4:Yb3+, Er3+ upconversion nanoparticles (UCNPs) with and without an inert (undoped NaYF4) shell have been successfully synthesized and the effects of shell thickness on the upconversion luminescence (UCL) and temperature sensing properties were systematically investigated. It was found that the NaYF4 shell and its thickness do not affect the RHS values and thermal sensitivity, but can obviously improve the UCL intensity of NaYF4:Yb3+, Er3+ UCNPs. It implies that the core-shell structured NaYF4:Yb3+, Er3+@NaYF4 UCNPs with excellent UCL properties have great potential to be used as temperature sensing probes in biomedical fields, without considering the influences of the shell thickness on their temperature sensing properties.

scholarly journals Upconversion luminescence and temperature sensing properties of NaGd(WO4)2:Yb3+/Er3+@SiO2 core–shell nanoparticles

RSC Advances ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 3981-3989
Author(s):  
Lu Zheng ◽  
Xinyi Huang ◽  
Jiuping Zhong ◽  
Zijun Wang ◽  
Xiaoning Cheng
Keyword(s):  
Upconversion Luminescence ◽  
Silica Shell ◽  
Temperature Sensing ◽  
Upconversion Nanoparticles ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Sensing Properties ◽  
The Core ◽  
Thermal Sensing ◽  
Core Shell Nanoparticles

A shell of SiO2 with tunable thickness was uniformly coated on NaGd(WO4)2:Yb3+/Er3+ core upconversion nanoparticles (UCNPs). The effects of the silica shell on UC luminescence and thermal sensing properties of the core–shell UCNPs were investigated.

Study on the Ag@SiO2 Enhanced the Luminous Intensity of the Terbium Complexes with Benzoic Acid and 1,10-phenanthroline

2014 ◽  
Vol 472 ◽  
pp. 711-714 ◽  
Author(s):  
Bin Yue ◽  
Yuan Li ◽  
Kai Kong ◽  
Hai Bin Chu ◽  
Yong Liang Zhao
Keyword(s):  
Benzoic Acid ◽  
Emission Intensity ◽  
Shell Thickness ◽  
Silica Shell ◽  
Excitation Wavelength ◽  
Core Shell ◽  
Enhanced Fluorescence ◽  
The Core ◽  
Transmission Electron ◽  
Terbium Complexes

Five kinds of terbium complexes have been synthesized respectively with benzoic acid, 1,10-phenanthroline and 2,2'-bipyridine as ligands. The core-shell Ag@SiO2nanocomposites was prepared. The result of transmission electron microscopy (TEM) shows the diameter of the nanosilver is about 50 nm and the thickness of the silica shell is 10, 25 and 80 nm. Combine the nanoparticles composite with terbium complexes, we explore the changes of excitation wavelength and emission intensity. The results show that: by loading the terbium complexes above the different size of nanoparticles, the excitation wavelengths of complexes do not shift, and the emission intensity of the complexes are enhanced in the presence of Ag@SiO2nanoparticles because of metal-enhanced fluorescence (MEF), but at only a limited shell thickness particle region.

Synthesis and Optical Properties of CdSe and CdSe/ZnS Core/Shell Quantum Dots

2015 ◽  
Vol 1085 ◽  
pp. 176-181
Author(s):  
Puspendu Barik ◽  
Arup Ratan Mandal ◽  
Denis V. Kuznetsov ◽  
Anna Yu. Godymchuk
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Excitation Wavelength ◽  
Core Shell ◽  
Shell Material ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
X Ray ◽  
The Core ◽  
Transmission Electron

In this work, we have synthesized homogeneous, ordered CdSe and CdSe/ZnS core/shell quantum dots (QDs) by chemical route and characterized them using X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), and Photoluminescence (PL) spectroscopy. Coating with shell material was confirmed by red shift as well as enhancement in the PL peak compared to bare QDs. DLS data showed QDs and core/shell to be stable. PL spectra are red shifted relative to the excitation wavelength. Bare QDs and the core/shell material shows a Stoke-shift of 16 and 18 meV respectively.

scholarly journals Excitation-power-dependent upconversion luminescence competition in single β-NaYbF4:Er microcrystal pumped at 808 nm

2021 ◽  
Author(s):  
Maohui Yuan ◽  
Zining Yang ◽  
Xu Yang ◽  
Linxuan Wang ◽  
Rui Wang ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Upconversion Luminescence ◽  
Excitation Power ◽  
Excitation Intensity ◽  
Excitation Wavelength ◽  
Water Molecules ◽  
Biological Applications ◽  
One Pot ◽  
Color Changes ◽  
Particle Level

Abstract Controlling the upconversion luminescence (UCL) intensity ratio, especially pumped at 808 nm, is of fundamental importance in biological applications due to the water molecules exhibiting low absorption at this excitation wavelength. In this work, a series of β-NaYbF4:Er microrods were synthesized by a simple one-pot hydrothermal method and their intense green (545 nm) and red (650 nm) UCL were experimentally investigated based on single particle level under the excitation of 808 nm continuous-wave (CW) laser. Interestingly, the competition between the green and red UCL can be observed in highly Yb3+-doped microcrystals as the excitation intensity gradually increases, which leads to the UCL color changes from green to orange. However, the microcrystals doped with low Yb3+ concentration keep green color which is independent on the excitation power. Further investigations demonstrate that the cross-relaxation (CR) processes between Yb3+ and Er3+ ions result in the UCL competition.

Enhancment of Upconversion Luminescence of Lanthanide-doped Nanocrystals Through Non-lanthanide Ions Doping Core-shell Nanoarchitecture

2016 ◽  
Vol 37 (3) ◽  
pp. 286-293
Author(s):  
马丹阳 MA Dan-yang ◽  
丁明烨 DING Ming-ye ◽  
戴建斌 DAI Jian-bin ◽  
胡琪唯 HU Qi-wei ◽  
潘雅静 PAN Ya-jing ◽  
...  
Keyword(s):  
Upconversion Luminescence ◽  
Lanthanide Ions ◽  
Core Shell

Synthesis and Inkjet Printing of NaYF4:Ln3+@NaYF4 Core–Shell Nanoparticles with Enhanced Upconversion Fluorescence for Anti-Counterfeiting Applications

2020 ◽  
Vol 20 (3) ◽  
pp. 1511-1519 ◽  
Author(s):  
Ya Song ◽  
Guo Gong ◽  
Jingjing Du ◽  
Shaowen Xie ◽  
Min Ouyang ◽  
...  
Keyword(s):  
Inkjet Printing ◽  
Hexagonal Phase ◽  
Upconversion Luminescence ◽  
Optical Data Storage ◽  
Lanthanide Ions ◽  
Optical Data ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles ◽  
Core Nanoparticles

Recently, lanthanide-doped upconversion luminescent materials have showed great potential in optical data storage, information encryption and anti-counterfeiting. However, the low upconversion luminescence still limited their applications. In this work, we fabricated RGB NaYF4:Ln3+@NaYF4 core–shell nanoparticles (CSNPs) with enhanced upconversion luminescence by coating an inert NaYF4 shell onto NaYF4:Ln3+ core nanoparticles via thermal decomposition method. The effect of increased shell temperature and addition of shell precursors on crystal phase, morphology and luminescent property of the synthesized CSNPs were systematically investigated. It was demonstrated that high shell growing temperature facilitated the formation of pure β-NaYF4 CSNPs. Upon increasing amount of shell precursors, the morphologies of hexagonal phase NaYF4 CSNPs changed from nanorod to nanocube and showed different luminescent properties. Pure hexagonal phase NaYF4 CSNPs with highest upconversion luminescence of about 15 times higher than NaYF4:Ln3+ core nanoparticles can be prepared at 310 °C with the addition of shell precursors at 3 mmol. Moreover, three-primary-color (RGB) CSNPs with enhanced upconversion luminescence were successfully prepared by changing the doping pair of lanthanide ions in core. The synthesized RGB CSNPs were fabricated into environment friendly luminescent ink by sequential surface modification by PAA ligand and dispersing in mixture solvent of ethanol, water and glycerol. Comparative results showed that the fluorescence enhanced RGB CSNPs inks were more suitable for inkjet printing of multicolored, complex and high resolution luminescent anti-counterfeiting patterns on paper substrates.

scholarly journals LiYF4:Yb/LiYF4 and LiYF4:Yb,Er/LiYF4 core/shell nanocrystals with luminescence decay times similar to YLF laser crystals and the upconversion quantum yield of the Yb,Er doped nanocrystals

Nano Research ◽  
2020 ◽  
Vol 14 (3) ◽  
pp. 797-806
Author(s):  
Frederike Carl ◽  
Leonie Birk ◽  
Bettina Grauel ◽  
Monica Pons ◽  
Christian Würth ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Upconversion Luminescence ◽  
Excitation Power ◽  
Luminescence Decay ◽  
Core Shell ◽  
Excitation Power Density ◽  
The Core ◽  
Decay Times ◽  
Laser Crystals ◽  
Shell Particles

AbstractWe developed a procedure to prepare luminescent LiYF4:Yb/LiYF4 and LiYF4:Yb,Er/LiYF4 core/shell nanocrystals with a size of approximately 40 nm revealing luminescence decay times of the dopant ions that approach those of high-quality laser crystals of LiYF4:Yb (Yb:YLF) and LiYF4:Yb,Er (Yb,Er:YLF) with identical doping concentrations. As the luminescence decay times of Yb3+ and Er3+ are known to be very sensitive to the presence of quenchers, the long decay times of the core/shell nanocrystals indicate a very low number of defects in the core particles and at the core/shell interfaces. This improvement in the performance was achieved by introducing two important modifications in the commonly used oleic acid based synthesis. First, the shell was prepared via a newly developed method characterized by a very low nucleation rate for particles of pure LiYF4 shell material. Second, anhydrous acetates were used as precursors and additional drying steps were applied to reduce the incorporation of OH− in the crystal lattice, known to quench the emission of Yb3+ ions. Excitation power density (P)-dependent absolute measurements of the upconversion luminescence quantum yield (ΦUC) of LiYF4:Yb,Er/LiYF4 core/shell particles reveal a maximum value of 1.25% at P of 180 Wcm−2. Although lower than the values reported for NaYF4:18%Yb,2%Er core/shell nanocrystals with comparable sizes, these ΦUC values are the highest reported so far for LiYF4:18%Yb,2%Er/LiYF4 nanocrystals without additional dopants. Further improvements may nevertheless be possible by optimizing the dopant concentrations in the LiYF4 nanocrystals.

scholarly journals Efficient Color Tuning of Upconversion Luminescence from Core-Shell Oxysulfide Nanoparticles

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Ying Tian ◽  
Jianxin Jiao ◽  
Xin Feng ◽  
Mingming Xing ◽  
Yong Peng ◽  
...  
Keyword(s):  
Shell Structure ◽  
Upconversion Luminescence ◽  
Cross Relaxation ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
The Core ◽  
Luminescence Efficiency ◽  
Core Shell Structure ◽  
Core Shell Nanoparticles ◽  
Triple Ion

The Y2O2S:Er3+@Y2O2S:Yb3+,Ho3+ core-shell up-conversion (UC) nanoparticles were successfully synthesized by the homogeneous co-precipitation method. The Y2O2S:Er3+@Y2O2S:Yb3+,Ho3+ core-shell nanoparticles exhibit bright green emissions under 980 nm excitation, while the triple-ion doped Y2O2S:Er3+,Yb3+,Ho3+ sample presents mainly red emissions. The intensity ratio of green-to-red emission of the core-shell and conventional triple-ion doped samples are 2.8 and 0.3, respectively. Investigations on the UC mechanisms show that emissions from Er3+ and Ho3+ ions are achieved simultaneously in the core-shell nanoparticles. This is due to the efficient energy transfers of Yb3+→Ho3+ within the shell layer and Yb3+→Er3+ between the shell and the core. While the triple-ion doped Y2O2S: Er3+,Yb3+,Ho3+ sample exhibits mainly the emissions of Er3+ along with weak luminescence of Ho3+ ion. Since the cross relaxation between Er3+ and Ho3+ ions in the Y2O2S:Er3+,Yb3+,Ho3+ nanoparticles can effectively suppress the emissions of Ho3+ ions. Yet, in the core-shell structure, this cross relaxation can be successfully restrained in the core-shell structure where Er3+ is in the core and Ho3+ is in the shell. Therefore, the construction of core-shell structure can improve the luminescence efficiency and provide a route for adjustment of emission color.

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