JOURNAL OF FLUORINE CHEMISTRY
·
2022
·
IF 2.226
Xuegang Zheng,Ying Chen,Shusheng Pan,Zhiyu Liu,Dekang Xu,Yueli Zhang,Hao Lin
In this paper, a range of Yb 3+ /Tm 3+ /Ho 3+ triple-doped NaYF 4 microcrystals (MCs) were successfully prepared by hydrothermal method and characterized by X-ray diffraction, which proved to be a hexagonal phase structure with uniformity. The morphology of NaYF 4 :20% Yb 3+ , 1% Ho 3+ MCs with different doping amounts of NaOH and citric acid were studied using scanning electron microscope, and the distribution of elements of this doping system was characterized by energy dispersive spectrometer. Upconversion luminescence (UCL) spectra of the MCs using a fluorescence spectrometer with 980 nm excitation were researched, and the results demonstrated that the tunable multi-color of the MCs can be achieved by varying the doping amount of different rare-earth ions. The UC mechanism of the MCs were systematically described. Li + doped the series MCs improved their UCL efficiency. By investigating the UCL the MCs of the Li + -doped system, the emission intensities of blue (450 nm, 475 nm), green (541 nm), and red (648 nm) light of the series MCs were increased by 2.75, 2.095, 2.65, and 2.87 times, which is of great significance for its application in light-emitting diodes and solar cells.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2017
·Vol. 7
·期 12
·448
·
IF 3.553
Dandan Ju,Feng Song,Yingdong Han,Wenjing Cui,Aihua Zhou,Shujing Liu,Xueqin Wang,Ming Feng,Chengguo Ming
We synthesized the uniform core-shell microstructured compounds with hexagonal phase NaYF4:Er/Yb microrods as the core and hexagonal phase NaLnF4(NaYbF4, NaLuF4:Yb/Tm, NaYF4:Yb/Er, NaYF4:Eu) as the shell based on the hydrothermal reaction. These microscale core-shell structures provided a platform for the spatially confining optical process while possessing high luminescence efficiency. The thickness of the shell could be controlled by adjusting the amounts of shell precursor, which significantly affected the intensity of the shell dopant ions emission and the emission color of core-shell upconversion luminescence (UCL). The uniform NaYF4@NaLnF4(Ln = Y, Lu, Yb) microrods, with a series of rare-earth ions doped into the core and shell layer at various doping concentrations, achieved color-tuning of the upconversion (UC) emission and dual-mode emission at the single-microcrystal level, thus allowing the efficient utilization of core-shell microcrystals in the photonics and security labeling. This study suggests a new class of luminescent materials in the microscopic field.Keywords:NaYF4microcrystals;microscale core-shell structures;multicolor tuning;dual-mode emission
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Research Express
·
2023
·Vol. 10
·期 8
·086201
·
IF 2.3
Bing Liu,Jingheng Liang,Lili Wang,Zian Cheak Tiu
β-NaYF4: Yb3+/Tm3+/Zr4+ microcrystals are synthesized by a facile hydrothermal route. The up-conversion (UC) luminescence and photoelectric effects are enhanced simultaneously with the introduction of Zr4+ ions under IR excitation. With the Tm3+ ions fluorescence spectra under 980 nm excitation, the blue and red emissions reached the highest intensity in the case of 4 mol% Zr4+ doping. Taking the advantage of Zr4+ stimulates the free electrons transfer from the valence band (VB) to the conduction band (CB) in β-NaYF4:Yb3+/Tm3+/Zr4+ microcrystals, the photocurrent reached the highest intensity in the case of 4 mol% Zr4+ doping at 780 nm excitation. The β-NaYF4: Yb3+/Tm3+/Zr4+ microcrystals with both enhanced UC luminescence and photoelectric properties are highly potential to contribute in photovoltaic and infrared sensors application.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2018
·
IF 0
Wen Qi,Qian Wu,Joseph G. Shapter,Meng Duan,Sheng Yang,Guo Gao
Chirality, universal characteristics of nature, introduces asymmetry in synthetic materials. Revealing the microscopic asymmetry of macroscopically symmetric materials is the key to control the growth of chiral materials and give full play to their application potential. Materials for photon upconversion (UC) are of great interest for many applications owing to their anti-Stoke luminescence process, especially for chiral UC materials. For the preparation of UC materials, a tiny change in reaction parameters will lead to variations in morphology, phase components, and fluorescence intensity, as well as its chirality. Because of the strict reaction conditions for the formation of chiral UC materials, there are no reports of the successful synthesis of chiral UC materials. Therefore, a facile method for the controllable synthesis of chiral UC materials is highly desired. Herein, chiral-assembled hexagonal prisms of β-NaYF4:Er3+/Yb3+ microcrystals were synthesized to realize the smart manipulation of their morphology as well as a great improvement of the fluorescence efficiency. We proposed a three-stage doped β-NaYF4 crystal growth mechanism on mesoscale regulation, where the fluorescence enhancement principle of chirality was revealed. The enhancement of fluorescence efficiency of chiral UC materials endows their promising application in luminescent displays.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
JOURNAL OF LUMINESCENCE
·
2020
·
IF 3.28
Hao Tang,Hua Zhou,Xianhua Cheng
The green and red upconversion (UC) emissions of 35 mol% Ca 2+ doped β-NaYF 4 :Yb 3+ /Er 3+ microcrystals were improved to 102.8 and 43.1 times higher than those of Ca 2+ -free counterparts. X-ray powder diffraction spectra, scanning electron microscopy, Fourier transform infrared spectroscopy , upconversion luminescence (UCL) spectroscopy and Judd-Ofelt analysis were performed to investigate the mechanism of UCL intensity enhancement caused by Ca 2+ doping. The hexagonal-to-cubic phase transition was observed when Ca 2+ doping concentration exceeded 35 mol%. The incorporation of Ca 2+ into hexagonal microcrystals lattice induced unit cell volume enhancement and microcrystals surface to volume ratio variation, which affected the UCL intensity by hindering the non-radiative energy loss process via Yb 3+ /Er 3+ ions and changing the amount of surface quenchers adsorbed on the microcrystals surface. The hypersensitive transition related local crystal field asymmetry around Er 3+ in the grown hexagonal microcrystals was also investigated by Judd-Ofelt analysis but unexpectedly found to be the less dominant factor for the UCL intensity variation. This study helps to realize the mechanism of impurity ion doping resulted UCL intensity enhancement, which is instructive for high-performance UC microcrystals synthesis.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Light-Science & Applications
·
2021
·Vol. 10
·期 1
·1-8
·
IF 17.782
Mao Yuanhao,Zhao Dong,Yan Shen,Zhang Hongjia,Li Juan,Han Kai,Xu Xiaojun,Guo Chuan,Yang Lexian,Zhang Chaofan,Huang Kun,Chen Yulin
Vacuum ultraviolet (VUV) lasers have demonstrated great potential as the light source for various spectroscopies, which, if they can be focused into a small beam spot, will not only allow investigation of mesoscopic materials and structures but also find application in the manufacture of nano-objects with excellent precision. In this work, we report the construction of a 177 nm VUV laser that can achieve a record-small (~0.76 μm) focal spot at a long focal length (~45 mm) by using a flat lens without spherical aberration. The size of the beam spot of this VUV laser was tested using a metal grating and exfoliated graphene flakes, and we demonstrated its application in a fluorescence spectroscopy study on pure and Tm 3+ -doped NaYF 4 microcrystals, revealing a new emission band that cannot be observed in the traditional up-conversion process. In addition, this laser system would be an ideal light source for spatially and angle-resolved photoemission spectroscopy.
研究领域:
物理学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2016
·Vol. 52
·期 2
·869-877
·
IF 2.302
Fan Shaohua,Wang Shikai,Xu Wenbin,Li Meng,Sun Hongtao,Hu Lili
Efficient upconversion (UC) microcrystals are important for the development of novel photonic markers, solid-state lasers, displays, etc. Herein, we report on greatly enhanced UC emission in β-NaYF 4 :20Yb,2Er microcrystals via a simple ion-exchange reaction. The ion exchange accompanying with an ionic redistribution process is demonstrated. By simply controlling the amount of NaF (0–8.0 mmol), reaction temperature (140–220 °C), and duration (0–144 h), enormous enhancement of the UC emission up to ~4200 times is obtained compared with the pre-synthesized β-NaYF 4 :20Yb,2Er microcrystals. The decrease of body defects and change of local structure around lanthanide may account for the UC emission enhancement. This method may apply to other UC materials to increase the UC emission efficiency.
研究领域:
材料科学
·
光子学
·
纳米技术
·
无机化学
·
发光材料
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2015
·
IF 2.999
Chuanying Wang,Xianhua Cheng
β-NaYF 4 :Yb 3+ /Er 3+ microcrystals codoped with Cr 3+ ions were prepared for the first time via a facile hydrothermal method . The influence of doping concentration of Cr 3+ ions on growth and upconversion (UC) luminescence properties of β-NaYF 4 :Yb 3+ /Er 3+ microcrystals were investigated in detail. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra and photoluminescence (PL) spectra were used for characterization. The results demonstrated that the morphology and size of β-NaYF 4 :Yb 3+ /Er 3+ microcrystals were influenced by doping concentration of Cr 3+ ions, the possible mechanism was proposed. The UC intensity of β-NaYF 4 :Yb 3+ /Er 3+ microcrystals was significantly enhanced by doping of Cr 3+ ions. In contrast to β-NaYF 4 :Yb 3+ /Er 3+ microcrystals without doping of Cr 3+ ions, the green and red emission intensities of the microcrystals codoped with 15 mol% Cr 3+ ions were enhanced by 16 and 7 times, respectively. The enhancement of the UC intensities should be ascribed to the distortion of local symmetry around Er 3+ ions, the UC mechanism was discussed. This work will be helpful for improving the UC intensity of other lanthanide-doped UC nano- and micro-crystals.
研究领域:
材料科学
·
无机化学
·
光功能材料
·
纳米医学
·
生物成像
·
分子影像学
·
光学材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）