Phase-Selective Hydrothermal Preparation and Upconversion Luminescence of NaYF4:Yb3+,Tm3+

2016 ◽  
Vol 690 ◽  
pp. 120-125 ◽  
Author(s):  
Thanataon Pornpatdetaudom ◽  
Karn Serivalsatit
Keyword(s):  
Reaction Time ◽  
Near Infrared ◽  
Hexagonal Phase ◽  
Upconversion Luminescence ◽  
Upconversion Emission ◽  
High Energy ◽  
Lanthanide Ions ◽  
Cubic Phase ◽  
Good Efficiency ◽  
Hydrothermal Temperature

Upconversion luminescence materials have been proved to have a good efficiency on converting low energy light to high energy light. These materials have received considerable attentions for many applications such as bio-labels, sensors, using for developing solar cells and photocatalytic applications under sunlight. Among many inorganic host materials, NaYF4 has been proved to be the best for doping lanthanide ions and have a good upconversion emission due to its low phonon energy, chemical stability, and transparency in the near infrared to ultraviolet range. In this study, NaYF4:Yb3+,Tm3+ upconversion luminescence materials were synthesized by hydrothermal method at temperature of 90 to 200 °C for period between 1 to 24 hours. The synthesized NaYF4:Yb3+,Tm3+ were characterized by X-ray diffraction, scanning electron microscopy, and fluorescence spectroscopy. The hydrothermal temperature and reaction time have strongly influence on phases and upconversion emission of the synthesized NaYF4:Yb3+,Tm3+. At 90 °C for 1 hour of reaction time, the pure cubic phase of NaYF4:Yb3+,Tm3+ was found. After increasing temperature and reaction time, the NaYF4:Yb3+,Tm3+ converted from cubic phase to hexagonal phase. Under excitation of 980 nm diode laser, the hexagonal NaYF4:Yb3+,Tm3+ exhibited the emission wavelength at about 656 nm (3F2 → 3H6), 469, 492, 552 nm (1G4 → 3H6), 537 nm (1D2 → 3H5), 450, 461 nm (1D2 → 3F4), 362 nm (1D2 → 3H6) and 345 nm (1I6 → 3F4). The upconversion emission intensity of the hexagonal NaYF4:Yb3+,Tm3+ was much stronger, compared with that of the cubic NaYF4:Yb3+,Tm3+.

scholarly journals Nano-Crystallization of Ln-Fluoride Crystals in Glass-Ceramics via Inducing of Yb3+ for Efficient Near-Infrared Upconversion Luminescence of Tm3+

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1033
Author(s):  
Jianfeng Li ◽  
Yi Long ◽  
Qichao Zhao ◽  
Shupei Zheng ◽  
Zaijin Fang ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Near Infrared ◽  
Upconversion Luminescence ◽  
Glass Ceramics ◽  
Upconversion Emission ◽  
Ceramic Composites ◽  
Wide Range ◽  
Transmission Window ◽  
Optical Applications ◽  
Upconversion Emissions

Transparent glass-ceramic composites embedded with Ln-fluoride nanocrystals are prepared in this work to enhance the upconversion luminescence of Tm3+. The crystalline phases, microstructures, and photoluminescence properties of samples are carefully investigated. KYb3F10 nanocrystals are proved to controllably precipitate in the glass-ceramics via the inducing of Yb3+ when the doping concentration varies from 0.5 to 1.5 mol%. Pure near-infrared upconversion emissions are observed and the emission intensities are enhanced in the glass-ceramics as compared to in the precursor glass due to the incorporation of Tm3+ into the KYb3F10 crystal structures via substitutions for Yb3+. Furthermore, KYb2F7 crystals are also nano-crystallized in the glass-ceramics when the Yb3+ concentration exceeds 2.0 mol%. The upconversion emission intensity of Tm3+ is further enhanced by seven times as Tm3+ enters the lattice sites of pure KYb2F7 nanocrystals. The designed glass ceramics provide efficient gain materials for optical applications in the biological transmission window. Moreover, the controllable nano-crystallization strategy induced by Yb3+ opens a new way for engineering a wide range of functional nanomaterials with effective incorporation of Ln3+ ions into fluoride crystal structures.

High-energy organic group-induced spectrally pure upconversion emission in novel zirconate-/hafnate-based nanocrystals

CrystEngComm ◽  
2015 ◽  
Vol 17 (37) ◽  
pp. 7169-7174 ◽  
Author(s):  
Xianghong He ◽  
Bing Yan
Keyword(s):  
Pump Power ◽  
Near Infrared ◽  
Incident Light ◽  
Upconversion Emission ◽  
High Energy ◽  
Single Band ◽  
Organic Group ◽  
Red Fluorescence

A series of novel fluoride-based nanophosphors (NPs) exhibiting spectrally pure upconversion (UC) red fluorescence upon near-infrared (980 nm) excitation. The single-band deep-red UC luminescence feature of K3MF7:Yb3+,Er3+ (M = Zr, Hf) NPs is independent of the doping levels of Yb3+–Er3+ and the pump power of incident light.

Upconversion lanthanide nanomaterials: basics introduction, synthesis approaches, mechanism and application in photodetector and photovoltaic devices

2021 ◽  
Author(s):  
Baharak Mehrdel ◽  
Ali Nikbakht ◽  
Azlan Abdul Aziz ◽  
Mahmood S. Jameel ◽  
Mohammed Ali Dheyab ◽  
...  
Keyword(s):  
Optical Properties ◽  
Near Infrared ◽  
Surface Passivation ◽  
Upconversion Emission ◽  
High Energy ◽  
Photovoltaic Devices ◽  
Plasmonic Enhancement ◽  
Host Matrix ◽  
Emission Enhancement ◽  
Improved Performance

Abstract Upconversion (UC) of lanthanide-doped nanostructure has the unique ability to convert low energy infrared (IR) light to high energy photons, which has significant potential for energy conversion applications. This review concisely discusses the basic concepts and fundamental theories of lanthanide nanostructures, synthesis techniques, and enhancement methods of upconversion for photovoltaic and for near-infrared (NIR) photodetector application. In addition, a few examples of lanthanide-doped nanostructures with improved performance were discussed, with particular emphasis on upconversion emission enhancement using coupling plasmon. The use of UC materials has been shown to significantly improve the NIR light-harvesting properties of photovoltaic devices and photocatalytic materials. However, the inefficiency of UC emission also prompted the need for additional modification of the optical properties of UC material. This improvement entailed the proper selection of the host matrix and optimization of the sensitizer and activator concentrations, followed by subjecting the UC material to surface-passivation, plasmonic enhancement, or doping. As expected, improving the optical properties of UC materials can lead to enhanced efficiency of photodetectors and photovoltaic devices.

Synthesis of Cobalt Sulfide Nanocrystallites via an Efficient Microwave Hydrothermal Process

2012 ◽  
Vol 512-515 ◽  
pp. 162-165
Author(s):  
Bi Li ◽  
Li Yun Cao ◽  
Jian Feng Huang ◽  
Jian Peng Wu
Keyword(s):  
Grain Size ◽  
Hexagonal Phase ◽  
Hydrothermal Process ◽  
High Energy ◽  
High Energy Density ◽  
Cobalt Sulfide ◽  
Nitrate Hexahydrate ◽  
Oriented Growth ◽  
Hydrothermal Temperature ◽  
Microwave Hydrothermal

Nanostructured cobalt sulfide(CoS) can be widely used as high energy density batteries, supercapacitors, solar photovoltaic materials and catalysts due to its excellent electronical, optical, magnetic and catalytic performance. In order to synthesize CoS crystallites in a efficient route, a facile microwave hydrothermal process was developed by using cobalt nitrate hexahydrate and thioacetamide(TAA) as source materials. The phase compositions and morphologies of the crystallites were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The influences of microwave hydrothermal temperature and time on the phase, grain size and morphology of the CoS nanocrystallites were particularly investigated. Results show that CoS crystallites can be obtained at the hydrothermal temperature of 180 °C. The as-synthesized CoS nanocrystallites are hexagonal phase that with the grain size of 10~30 nm. With the increase of hydrothermal time, the increase in particle size and the (102)-oriented growth are obviously.

scholarly journals Huge upconversion luminescence enhancement by a cascade optical field modulation strategy facilitating selective multispectral narrow-band near-infrared photodetection

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Yanan Ji ◽  
Wen Xu ◽  
Nan Ding ◽  
Haitao Yang ◽  
Hongwei Song ◽  
...  
Keyword(s):  
Near Infrared ◽  
Response Times ◽  
Modulation Frequency ◽  
Incident Light ◽  
Upconversion Luminescence ◽  
Optical Field ◽  
Lanthanide Ions ◽  
Hierarchical Architecture ◽  
Upconversion Nanocrystals ◽  
Field Modulation

Abstract Since selective detection of multiple narrow spectral bands in the near-infrared (NIR) region still poses a fundamental challenge, we have, in this work, developed NIR photodetectors (PDs) using photon upconversion nanocrystals (UCNCs) combined with perovskite films. To conquer the relatively high pumping threshold of UCNCs, we designed a novel cascade optical field modulation strategy to boost upconversion luminescence (UCL) by cascading the superlensing effect of dielectric microlens arrays and the plasmonic effect of gold nanorods, which readily leads to a UCL enhancement by more than four orders of magnitude under weak light irradiation. By accommodating multiple optically active lanthanide ions in a core-shell-shell hierarchical architecture, developed PDs on top of this structure can detect three well-separated narrow bands in the NIR region, i.e., those centered at 808, 980, and 1540 nm. Due to the large UCL enhancement, the obtained PDs demonstrate extremely high responsivities of 30.73, 23.15, and 12.20 A W−1 and detectivities of 5.36, 3.45, and 1.91 × 1011 Jones for 808, 980, and 1540 nm light detection, respectively, together with short response times in the range of 80–120 ms. Moreover, we demonstrate for the first time that the response to the excitation modulation frequency of a PD can be employed to discriminate the incident light wavelength. We believe that our work provides novel insight for developing NIR PDs and that it can spur the development of other applications using upconversion nanotechnology.

scholarly journals Hydrothermal Synthesis and Tunable Multicolor Upconversion Emission of Cubic Phase Y2O3Nanoparticles

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Haibo Wang ◽  
Chao Qian ◽  
Zhigao Yi ◽  
Ling Rao ◽  
Hongrong Liu ◽  
...  
Keyword(s):  
Upconversion Luminescence ◽  
Upconversion Emission ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Light Yellow ◽  
Color Displays ◽  
Transmission Electron ◽  
Subsequent Calcination ◽  
Upconversion Emissions

Highly crystalline body-centered cubic structure Y2O3with lanthanide (Ln) codopants (Ln = Yb3+/Er3+and Yb3+/Ho3+) has been synthesized via a moderate hydrothermal method in combination with a subsequent calcination. The structure and morphology of Y(OH)3precursors and Y2O3nanoparticles were characterized by X-ray diffraction and transmission electron microscopy. The results reveal that the Y2O3nanoparticles possess cubic phase and form the quasispherical structure. The upconversion luminescence properties of Y2O3nanoparticles doped with different Ln3+(Yb3+/ Er3+and Yb3+/ Ho3+) ions were well investigated under the 980 nm excitation. The results show that the Yb3+/Er3+and Yb3+/Ho3+codoped Y2O3nanoparticles exhibit strong red and light yellow upconversion emissions, respectively. It is expected that these Y2O3nanoparticles with tunable multicolor output and intense red upconversion emission may have potential application in color displays and biolabels.

Phase Control of Nanosized NaYF4 Upconversion Particles

2012 ◽  
Vol 512-515 ◽  
pp. 235-238
Author(s):  
Jing Guo ◽  
Fei Zhong Ma ◽  
Ying Shi ◽  
Jian Jun Xie
Keyword(s):  
Near Infrared ◽  
Water Solubility ◽  
High Efficiency ◽  
Hexagonal Phase ◽  
Upconversion Luminescence ◽  
Co Doping ◽  
Selected Area Electron Diffraction ◽  
Host Materials ◽  
Hexagonal Shape ◽  
Diffraction Patterns

The hexagonal phase NaYF4 (Na(Y1.5Na0.5)F6, β-NaYF4 type) is a kind of ideal host materials for upconversion luminescence with high efficiency. The synthesis of monophase hexagonal NaYF4:Yb3+/Er3+ nanoparticles has been investigated by solvothermal processing under 200° for 24hrs. It was found that solvents adopted had a great impact on formation of β-NaYF4. X-ray diffraction patterns indicated that monophase α-NaYF4 and β-NaYF4 nanosized grains could be synthesized successfully under environment of ethanol and oleic acid respectively, whereas the mixture of α-NaYF4 and Na5Y9F32 phases were obtained when water was used as solvent. The synthesized pure β-NaYF4 nanoparticles were uniformly monodispersed in hexagonal shape with typical length of 150~200nm and diameter of 50~100nm. Selected area electron diffraction observation revealed that the as-prepared nanorods are of single crystalline nature. By co-doping (20%)Yb-(2%)Er, the β-NaYF4 nanosized grains exhibited bright green upconversion luminescence centered at 538nm under the radiation of near-infrared (NIR) laser(nm). The FTIR spectrum shows theβ-NaYF4 have the potential of water-solubility for the strong bands at around 3444 and 1634 cm-1.

Influence of Different Gd3+ Doping on the Upconversion Luminescence Properties and Morphology of NaYF4:Yb,Er

2017 ◽  
Vol 726 ◽  
pp. 250-254 ◽  
Author(s):  
Cui Ping Zhong ◽  
Shu Wang Duo ◽  
Jie Jun Zhang
Keyword(s):  
Hexagonal Phase ◽  
Upconversion Luminescence ◽  
Upconversion Emission ◽  
Raw Material ◽  
Luminous Intensity ◽  
Mechanism Analysis ◽  
Doping Amount ◽  
Double Flower ◽  
Excitation Light ◽  
Fluorescence Test

Rare earth nitrate as the raw material, NaY/GdF4 upconversion luminescent nanoparticles were prepared by hydrothermal method, its diameter is about 200nm. By changing the Gd3+ doping amount achieved NaYF4 transition from the tetragonal to hexagonal phase, and the upconversion emission intensity can be improved by optimizing Gd3+ content. In 980nm excitation light source for the fluorescence test showed that the introduction of Gd3+ can effectively promote size reduction of NaY/GdF4 crystals and decrease luminous intensity. Through mechanism analysis we know that is related to nanosize effect. At the same time, we discussed the upconversion luminescence mechanism of NaY/GdF4 nanocrystals luminous intensity in different wavelength bands and the SEM show the morphology transformation from spherical to double-flower.

scholarly journals Synthesis, Tunable Multicolor Output, and High Pure Red Upconversion Emission of Lanthanide-Doped Lu2O3Nanosheets

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Lingzhen Yin ◽  
Tianmei Zeng ◽  
Zhigao Yi ◽  
Chao Qian ◽  
Hongrong Liu
Keyword(s):  
Electron Microscope ◽  
Upconversion Emission ◽  
Lanthanide Ions ◽  
Cubic Phase ◽  
Dehydration Process ◽  
X Ray Diffraction ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Scanning Electron

Yb3+and Ln3+(Ln = Er, Ho) codoped Lu2O3square nanocubic sheets were successfully synthesized via a facile hydrothermal method followed by a subsequent dehydration process. The crystal phase, morphology, and composition of hydroxide precursors and target oxides were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), and energy-dispersive X-ray spectroscope (EDS). Results present the as-prepared Lu2O3crystallized in cubic phase, and the monodispersed square nanosheets were maintained both in hydroxide and oxides. Moreover, under 980 nm laser diode (LD) excitation, multicolor output from red to yellow was realized by codoped different lanthanide ions in Lu2O3. It is noteworthy that high pure strong red upconversion emission with red to green ratio of 443.3 of Er-containing nanocrystals was obtained, which is beneficial forin vivooptical bioimaging.

scholarly journals Enhancement of upconversion luminescence using photonic nanostructures

Nanophotonics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1359-1371
Author(s):  
Ananda Das ◽  
Kyuyoung Bae ◽  
Wounjhang Park
Keyword(s):  
Upconversion Luminescence ◽  
Upconversion Emission ◽  
High Energy ◽  
Therapeutic Agents ◽  
Biological Applications ◽  
Color Displays ◽  
Solar Energy Harvesting ◽  
Large Enhancement ◽  
Recent Developments ◽  
Work Done

AbstractLanthanide-based upconversion materials convert low energy infrared photons into high energy visible photons. These materials are of interest in a myriad of applications such as solar energy harvesting, color displays and photocatalysis. Upconversion nanoparticles (UCNPs) are also of interest in biological applications as bioimaging and therapeutic agents. However, the intrinsic conversion efficiency of UCNPs remains low for most applications. In this review, we survey the recent work done in increasing the upconversion emission by changing the local electric field experienced by the UCNPs using photonic nanostructures. We review both the underlying theory behind this photonic manipulation as well as experimental demonstrations of enhancement. We discuss the recent developments in the more common plasmonic designs as well as the emerging field of dielectric nanostructures. We find that improvements in design and fabrication of these nanostructures in the last few years have led to reported enhancements of over three orders of magnitude. This large enhancement has been achieved in not only nanostructures on films but also in nanostructures that can be dispersed into solution which is especially relevant for biological applications.

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