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1.
The commercial vacuum ultraviolet (VUV) red phosphor (Y, Gd)BO3:Eu3+ has low luminous efficiency and poor color purity. Our work aims to overcome this drawback and we mainly devote to investigating the luminescence mechanism, improving the commercial red phosphor, and seeking for new red emitting VUV materials with high efficiency. Based on the investigation of the photoluminescence mechanism of VUV phosphors, both the luminous efficiency and the color purity of (Y, Gd)BO3:Eu3+ are improved. Additionally, a series of novel VUV red phosphors have been developed, such as (Gd,Y)Al3(BO3)4:Eu3+ and (La,Gd)P3O9:Eu3+. This presentation is a review about the recent research progress of red phosphors for plasma displays (PDPs) applications in our group. 相似文献
2.
In this work, Sr3Al2O6: Eu2+ (Eu3+), Dy3+ phosphors have been prepared by hydrothermal treatment and subsequently postannealing approach, using Sr(NO3)2, Al(NO3)3·9H2O, and CO(NH2)2 as starting materials. The as-obtained phosphors were characterized by means of XRPD, FESEM, and PL techniques. In addition, many reaction parameters were studied in detail, including the initial mole ratios, hydrothermal reaction temperature, calcination temperature and calcination atmosphere. Remarkably, two scientific merits exist herein: Sr3Al2O6: Eu2+ (Eu3+), Dy3+ phosphors can be selectively obtained in a reducing atmosphere (H2/Ar, 20%+80%) and in air, respectively; adding certain amount of sodium citrate can alter the shape and size of Sr3Al2O6: Eu2+ (Eu3+), Dy3+ phosphors in essence. Besides, the luminescent properties of Sr3Al2O6: Eu2+ (Eu3+), Dy3+ phosphors were studied by excitation spectra, emission spectra and decay curves. 相似文献
3.
Dr. Hoang‐Duy Nguyen Dr. Chun Che Lin Prof. Dr. Ru‐Shi Liu 《Angewandte Chemie (International ed. in English)》2015,54(37):10862-10866
A facile approach for coating red fluoride phosphors with a moisture‐resistant alkyl phosphate layer with a thickness of 50–100 nm is reported. K2SiF6:Mn4+ particles were prepared by co‐precipitation and then coated by esterification of P2O5 with alcohols (methanol, ethanol, and isopropanol). This route was adopted to encapsulate the prepared phosphors using transition‐metal ions as cross‐linkers between the alkyl phosphate moieties. The coated phosphor particles exhibited a high water tolerance and retained approximately 87 % of their initial external quantum efficiency after aging under high‐humidity (85 %) and high‐temperature (85 °C) conditions for one month. Warm white‐light‐emitting diodes that consisted of blue InGaN chips, the prepared K2SiF6:Mn4+ phosphors, and either yellow Y3Al5O12:Ce3+ phosphors or green β‐SiAlON: Eu2+ phosphors showed excellent color rendition. 相似文献
4.
Chao Yin Mufei Yue Pengfei Jiang Ruirui Yang Xianju Zhou Wenliang Gao Rihong Cong Tao Yang 《化学:亚洲杂志》2019,14(9):1541-1548
Searching efficient red phosphors under near‐UV or blue light excitation is practically important to improve the current white light‐emitting diodes (WLEDs). Eu2+‐ and Mn4+‐based red phosphors have been extensively studied. Here we proposed that Eu3+ is also a promising activator when it resides on a noncentrosymmetric coordination site. We proved that Cd4GdO(BO3)3 is a good host, which has a significantly distorted coordination for Eu3+. A careful crystallographic study was performed on the solid solutions of Cd4Gd1‐xEuxO(BO3)3 (0≤x≤1) by Rietveld refinements. The as‐doped Eu3+ cations locate at the Gd3+ site and are well separated by CdO8, CdO6 and BO3 groups; thus, only a slight concentration quenching was observed at ≈80 atom % Eu3+. Most importantly, the parity‐forbidden law of 4f‐4f transitions for Eu3+ are severely depressed, thus the absorptions at ≈393 and ≈465 nm are remarkable. Cd4Gd0.2Eu0.8O(BO3)3 can be pumped by a 395 nm LED chip to give a bright red emission, and when mixed with other commercial blue and green phosphors, it can emit the proper white light (0.3657, 0.3613) with a suitable Ra≈87 and correlated colour temperature ≈4326 K. In‐situ photoluminescence study indicated the low thermal quenching of these borate phosphors, especially under 465 nm excitation. Our case proves the practicability to develop near‐UV excited red phosphors in rare‐earth‐containing borates. 相似文献
5.
Jianwei Qiao Lixin Ning Maxim S. Molokeev Yu‐Chun Chuang Qinyuan Zhang Kenneth R. Poeppelmeier Zhiguo Xia 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(33):11645-11650
Establishing an effective design principle in solid‐state materials for a blue‐light‐excited Eu2+‐doped red‐emitting oxide‐based phosphors remains one of the significant challenges for white light‐emitting diodes (WLEDs). Selective occupation of Eu2+ in inorganic polyhedra with small coordination numbers results in broad‐band red emission as a result of enhanced crystal‐field splitting of 5d levels. Rb3YSi2O7:Eu exhibits a broad emission band at λmax=622 nm under 450 nm excitation, and structural analysis and DFT calculations support the concept that Eu2+ ions preferably occupy RbO6 and YO6 polyhedra and show the characteristic red emission band of Eu2+. The excellent thermal quenching resistance, high color‐rendering index Ra (93), and low CCT (4013 K) of the WLEDs clearly demonstrate that site engineering of rare‐earth phosphors is an effective strategy to target tailored optical performance. 相似文献
6.
Synthesis,Structure, and Photoluminescence Properties of Novel KBaSc2(PO4)3:Ce3+/Eu2+/Tb3+ Phosphors for White‐Light‐Emitting Diodes
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Dr. Mengmeng Jiao Wei Lü Baiqi Shao Lingfei Zhao Prof. Hongpeng You 《Chemphyschem》2015,16(12):2663-2669
A series of novel KBaSc2(PO4)3:Ce3+/Eu2+/Tb3+phosphors are prepared using a solid‐state reaction. X‐ray diffraction analysis and Rietveld structure refinement are used to check the phase purity and crystal structure of the prepared samples. Ce3+‐ and Eu2+‐doped phosphors both have broad excitation and emission bands, owing to the spin‐ and orbital‐allowed electron transition between the 4f and 5d energy levels. By co‐doping the KBaSc2(PO4)3:Eu2+ and KBaSc2(PO4)3:Ce3+ phosphors with Tb3+ ions, tunable colors from blue to green can be obtained. The critical distance between the Eu2+ and Tb3+ ions is calculated by a concentration quenching method and the energy‐transfer mechanism for Eu2+→Tb3+ is studied by utilizing the Inokuti–Hirayama model. In addition, the quantum efficiencies of the prepared samples are measured. The results indicate that KBaSc2(PO4)3:Eu2+,Tb3+ and KBaSc2(PO4)3:Ce3+,Tb3+ phosphors might have potential applications in UV‐excited white‐light‐emitting diodes. 相似文献
7.
Tuning Mixed‐Valent Eu2+/Eu3+ in Strontium Formate Frameworks for Multichannel Photoluminescence
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Wei Liu Dr. Lijia Liu Dr. Yanlong Wang Lanhua Chen Dr. John A. McLeod Linju Yang Jia Zhao Dr. Zhiyong Liu Prof. Dr. Juan Diwu Prof. Dr. Zhifang Chai Prof. Dr. Thomas E. Albrecht‐Schmitt Dr. Guokui Liu Prof. Dr. Shuao Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(32):11170-11175
Cooperative performance of mixed‐valent Eu2+/Eu3+ in single‐compound phosphors offers significant advantages in color rendering and luminescence efficiency, but their synthesis is challenging because of Eu2+ oxidation. Using the tunable nature of the metal‐ion nodes in metal–organic frameworks (MOFs), we present an in situ reduction and crystallization route for preparing MOFs and doping Eu2+/Eu3+ with a controlled ratio. These materials exhibit rich photoluminescence, including intrinsic‐ and sensitized‐emissions of Eu2+ and Eu3+, and long‐lived luminescence from charge transfer. Color rendering can be easily achieved by fine‐tuning the valence states of Eu. A linear relation between temperature and the intensity ratio of Eu2+/Eu3+ emissions provides outstanding properties for applications as self‐calibrated luminescent thermometers with a wide working temperature range. Further incorporation of Tb3+ into the MOFs results in white light, utilizing all Eu2+,Tb3+, and Eu3+ emissions in a single crystalline lattice. 相似文献
8.
Enhancing the Photocatalytic Activity of Sr4Al14O25: Eu2+, Dy3+ Persistent Phosphors by Codoping with Bi3+ Ions
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Carlos R. García Jorge Oliva Maria Teresa Romero Luis A. Diaz‐Torres 《Photochemistry and photobiology》2016,92(2):231-237
The photocatalytic activity of Bismuth‐codoped Sr4Al14O25: Eu2+, Dy3+ persistent phosphors is studied by monitoring the degradation of the blue methylene dye UV light irradiation. Powder phosphors are obtained by a combustion synthesis method and a postannealing process in reductive atmosphere. The XRD patterns show a single orthorhombic phase Sr4Al14O25: Eu2+, Dy3+, Bi3+ phosphors even at high Bismuth dopant concentrations of 12 mol%, suggesting that Bi ions are well incorporated into the host lattice. SEM micrographs show irregular micrograins with sizes in the range of 0.5–20 μm. The samples present an intense greenish‐blue fluorescence and persistent emissions at 495 nm, attributed to the 5d–4f allowed transitions of Eu2+. The fluorescence decreases as Bi concentration increases; that suggest bismuth‐induced traps formation that in turn quench the luminescence. The photocatalytic evaluation of the powders was studied under both 365 nm UV and solar irradiations. Sample with 12 mol% of Bi presented the best MB degradation activity; 310 min of solar irradiation allow 100% MB degradation, whereas only 62.49% MB degradation is achieved under UV irradiation. Our results suggest that codoping the persistent phosphors with Bi3+ can be an alternative to enhance their photocatalytic activity. 相似文献
9.
Ultra‐Narrow‐Band Blue‐Emitting Oxoberyllates AELi2[Be4O6]:Eu2+ (AE=Sr,Ba) Paving the Way to Efficient RGB pc‐LEDs
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Philipp Strobel Christian Maak Volker Weiler Dr. Peter J. Schmidt Prof. Dr. Wolfgang Schnick 《Angewandte Chemie (International ed. in English)》2018,57(28):8739-8743
Highly efficient phosphor‐converted light‐emitting diodes (pc‐LEDs) are popular in lighting and high‐tech electronics applications. The main goals of present LED research are increasing light quality, preserving color point stability and reducing energy consumption. For those purposes excellent phosphors in all spectral regions are required. Here, we report on ultra‐narrow band blue emitting oxoberyllates AELi2[Be4O6]:Eu2+ (AE=Sr,Ba) exhibiting a rigid covalent network isotypic to the nitridoalumosilicate BaLi2[(Al2Si2)N6]:Eu2+. The oxoberyllates’ extremely small Stokes shift and unprecedented ultra‐narrow band blue emission with fwhm ≈25 nm (≈1200 cm?1) at λem=454–456 nm result from its rigid, highly condensed tetrahedra network. AELi2[Be4O6]:Eu2+ allows for using short‐wavelength blue LEDs (λem<440 nm) for efficient excitation of the ultra‐narrow band blue phosphor, for application in violet pumped white RGB phosphor LEDs with improved color point stability, excellent color rendering, and high energy efficiency. 相似文献
10.
Investigation of Luminescence Properties of Eu3+, Dy3+ and Gd3+ Doped MgAl2Si2O8 Red‐emitting Phosphors
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Rare‐earth‐doped aluminosilicates of alkaline earth MgAl2Si2O8: Eu3+, Dy3+ and MgAl2Si2O8: Eu3+, Gd3+ were synthesized by the solid state reaction method at 1300 oC. The phosphors were characterized by X‐ray powder diffraction (XRD), photoluminescence (PL), thermoluminescence (TL) and scanning electron microscopy (SEM). X‐ray powder diffraction studies show that the phosphors were crystallized in the triclinic crystal system. The phosphors show characteristic broad band phosphorescence of Eu3+. This broad band phosphorescence has red emission bands in the range of 580–705 nm corresponding to 5D0 → 7Fj (j:0,2,3,4) transitions of Eu3+. 相似文献
11.
Dr. Jin He Dr. Cheng Yan Minmin Huang Dr. Rui Shi Dr. Yibo Chen Prof. Chris D. Ling Prof. Zhao-Qing Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(25):5619-5628
In this work, a latent energy-transfer process in traditional Eu3+,Tb3+-doped phosphors is proposed and a new class of Eu3+,Tb3+-doped Na4CaSi3O9 (NCSO) phosphors is presented which is enabled by luminescence decay dynamics that optimize the electron-transfer energy process. Relative to other Eu3+,Tb3+-doped phosphors, the as-synthesized Eu3+,Tb3+-doped NCSO phosphors show improved large-scale tunable emission color from green to red upon UV excitation, controlled by the Tb3+/Eu3+ doping ratio. Detailed spectroscopic measurements in the vacuum ultraviolet (VUV)/UV/Vis region were used to determine the Eu3+–O2− charge-transfer energy, 4f–5d transition energies, and the energies of 4f excited multiplets of Eu3+ and Tb3+ with different 4fN electronic configurations. The Tb3+→Eu3+ energy-transfer pathway in the co-doped sample was systematically investigated, by employing luminescence decay dynamics analysis to elucidate the relevant energy-transfer mechanism in combination with the appropriate model simulation. To demonstrate their application potential, a prototype white-light-emitting diode (WLED) device was successfully fabricated by using the yellow luminescence NCSO:0.03Tb3+, 0.05Eu3+ phosphor with high thermal stability and a BaMgAl10O17:Eu2+ phosphor in combination with a near-UV chip. These findings open up a new avenue to realize and develop multifunctional high-performance phosphors by manipulating the energy-transfer process for practical applications. 相似文献
12.
Dr. Ning Guo Wei Lü Yongchao Jia Wenzhen Lv Qi Zhao Prof. Hongpeng You 《Chemphyschem》2013,14(1):192-197
A novel orange‐yellow‐emitting Ba3Gd(PO4)3:x Eu2+,y Mn2+ phosphor is prepared by high‐temperature solid‐state reaction. The crystal structure of Ba3Gd(PO4)3:0.005 Eu2+,0.04 Mn2+ is determined by Rietveld refinement analysis on powder X‐ray diffraction data, which shows that the cations are disordered on a single crystallographic site and the oxygen atoms are distributed over two partially occupied sites. The photoluminescence excitation spectra show that the developed phosphor has an efficient broad absorption band ranging from 230 to 420 nm, perfectly matching the characteristic emission of UV‐light emitting diode (LED) chips. The emission spectra show that the obtained phosphors possess tunable color emissions from yellowish‐green through yellow and ultimately to reddish‐orange by simply adjusting the Mn2+ content (y) in Ba3Gd(PO4)3:0.005 Eu2+,y Mn2+ host. The tunable color emissions origin from the change in intensity between the 4f–5d transitions in the Eu2+ ions and the 4T1‐6A1 transitions of the Mn2+ ions through the energy transfer from the Eu2+ to the Mn2+ ions. In addition, the mechanism of the energy transfer between the Eu2+ and Mn2+ ions are also studied in terms of the Inokuti–Hirayama theoretical model. The present results indicate that this novel orange‐yellow‐emitting phosphor can be used as a potential candidate for the application in white LEDs. 相似文献
13.
Dr. Mengmeng Jiao Wenzhen Lv Wei Lü Qi Zhao Baiqi Shao Prof. Hongpeng You 《Chemphyschem》2015,16(4):817-824
A series of Eu2+‐, Ce3+‐, and Tb3+‐doped Ca2Ga2SiO7 phosphors is synthesized by using a high‐temperature solid‐state reaction. The powder X‐ray diffraction and structure refinement data indicate that our prepared phosphors are single phased and the phosphor crystalizes in a tetrahedral system with the ${P\bar 42m}$ (113) space group. The Eu2+‐ and Ce3+‐doped phosphors both have broad excitation bands, which match well with the UV light‐emitting diodes chips. Under irradiation of λ=350 nm, Ca2Ga2SiO7:Eu2+ and Ca2Ga2SiO7:Ce3+, Li+ have green and blue emissions, respectively. Luminescence of Ca2Ga2SiO7:Tb3+, Li+ phosphor varies with the different Tb3+ contents. The thermal stability and energy‐migration mechanism of Ca2Ga2SiO7:Eu2+ are also studied. The investigation results indicate that the prepared Ca2Ga2SiO7:Eu2+ and Ca2Ga2SiO7:Ce3+, Li+ samples show potential as green and blue phosphors, respectively, for UV‐excited white‐light‐emitting diodes. 相似文献
14.
白光LED因亮度高、体积小、寿命长、高效节能、绿色环保等优点而引起人们的广泛关注,但是目前大部分白光LED用荧光粉的不足之处在于其发光效率较低,显色指数较差,色温较高,成本较高等等。红色荧光粉可明显改善白光LED的色温和显色指数,因此红色荧光粉在调制白光LED和改善其显色指数方面具有至关重要的作用。近年来红色荧光粉得到了深入研究,并有不少文献报道了新型的红色荧光粉。本文介绍了Eu3+掺杂的线状红光发射荧光粉、Eu2+掺杂的带状红光发射荧光粉并着重介绍了Eu2+掺杂的新型窄带红光发射荧光粉,以及目前Eu掺杂红色荧光粉发展的不足及其改善方法。 相似文献
15.
Motivated by the need for new phosphors of white light emitting diode (WLED) application, Ca0.95Nb2 O6:Eu3+0.05 phosphors were synthesized by high temperature solid‐state reaction. Increasing the content of doped‐Eu3+ and adding the co‐activator Bi3+ to improve the photoluminescence (PL) intensity of Ca1?xNb2 O6Eu3+x phosphors were investigated in detail. The effects of Eu3+ were better than that of Bi3+ on the PL intensity of Ca1?xNb2 O6Eu3+x phosphors. Compared with Y2O2 S:0.05Eu3+ the Ca0.70Nb2 O6:Eu3+0.03 phosphor could be excited efficiently by UV (395 nm) light and emit the red light at 614 nm with line spectra, which were coupled well with the characteristic emission from UV‐Near UV LED. The CIE (International Commission on Illumination) chromaticity coordinates (x?0.654, y?0.348) of Ca0.70Nb2O6:Eu3+0.03 were close to the NTSC (National Television Standard Committee) standard values. Therefore Ca0.70Nb2 O6:Eu3+0.03 might find application to UV‐Near UV InGaN chip‐based white light emitting diodes, which is further proved by the LED fabrication with the Ca0.70Nb2 O6:Eu3+0.03 phosphor. 相似文献
16.
Synthesis,Persistent Luminescence,and Thermoluminescence Properties of Yellow Sr3SiO5:Eu2+,RE3+ (RE=Ce,Nd, Dy,Ho, Er,Tm, Yb) and Orange‐Red Sr3−xBaxSiO5:Eu2+, Dy3+ Phosphor
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Dr. Ye Li Baohong Li Chenchen Ni Shuxia Yuan Jing Wang Prof. Qiang Tang Prof. Qiang Su 《化学:亚洲杂志》2014,9(2):494-499
Sunlight‐excitable orange or red persistent oxide phosphors with excellent performance are still in great need. Herein, an intense orange‐red Sr3?xBaxSiO5:Eu2+,Dy3+ persistent luminescence phosphor was successfully developed by a two‐step design strategy. The XRD patterns, photoluminescence excitation and emission spectra, and the thermoluminescence spectra were investigated in detail. By adding non‐equivalent trivalent rare earth co‐dopants to introduce foreign trapping centers, the persistent luminescence performance of Eu2+ in Sr3SiO5 was significantly modified. The yellow persistent emission intensity of Eu2+ was greatly enhanced by a factor of 4.5 in Sr3SiO5:Eu2+,Nd3+ compared with the previously reported Sr3SiO5:Eu2+, Dy3+. Furthermore, Sr ions were replaced with equivalent Ba to give Sr3?xBaxSiO5:Eu2+,Dy3+ phosphor, which shows yellow‐to‐orange‐red tunable persistent emissions from λ=570 to 591 nm as x is increased from 0 to 0.6. Additionally, the persistent emission intensity of Eu2+ is significantly improved by a factor of 2.7 in Sr3?xBaxSiO5:Eu2+,Dy3+ (x=0.2) compared with Sr3SiO5:Eu2+,Dy3+. A possible mechanism for enhanced and tunable persistent luminescence behavior of Eu2+ in Sr3?xBaxSiO5:Eu2+,RE3+ (RE=rare earth) is also proposed and discussed. 相似文献
17.
Ishwar Prasad Sahu D. P. Bisen Raunak Kumar Tamrakar Ravi Shrivastava 《Research on Chemical Intermediates》2016,42(3):1823-1843
The Ca2MgSi2O7:Eu2+ and Ca2MgSi2O7:Eu2+, Dy3+ long afterglow phosphors were synthesized under a weak reducing atmosphere by the traditional high temperature solid state reaction method. The synthesized phosphors were characterized by powder X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX) techniques. The luminescence properties were investigated using thermoluminescence (TL), photoluminescence (PL), long afterglow, mechanoluminescence (ML), and ML spectra techniques. The crystal structure of sintered phosphors was an akermanite type structure, which belongs to the tetragonal crystallography. TL properties of these phosphors were investigated, and the results were also compared. Under the ultraviolet excitation, the emission spectra of both prepared phosphors were composed of a broad band peaking at 535 nm, belonging to the broad emission band. When the Ca2MgSi2O7:Eu2+ phosphor is co-doped with Dy3+, the PL, afterglow and ML intensity is strongly enhanced. The decay graph indicates that both the sintered phosphors contain fast decay and slow decay process. The ML intensities of Ca2MgSi2O7:Eu2+ and Ca2MgSi2O7:Eu2+, Dy3+ phosphors were proportionally increased with the increase of impact velocity, which suggests that this phosphor can be used as sensors to detect the stress of an object. 相似文献
18.
We demonstrate herein a facile hydrothermal synthesis followed by post-annealing approach to selectively prepare MgAl2O4:Eu3+ nanoplates and nanoparticles. Series of scientific techniques such as XRPD, FESEM, TEM, HRTEM, and PL were adopted to characterize the as-prepared MgAl2O4:Eu3+ phosphors. First, by altering the amount of hexamethylenetetramine (abbr. HMTA) in solution, MgAl2O4:Eu3+ nanoplates occurred. Next, MgAl2O4:Eu3+ nanoparticles were prepared by adding certain amounts of sodium citrate and sodium dodecylbenzenesulfonate (abbr. SDBS). In particular, the MgAl2O4:Eu3+ nanoplates have novel porous structures. Besides, the MgAl2O4:Eu3+ phosphors exhibit excellent red-emitting properties based upon the characteristic transitions of Eu3+ from 5D0 → 7FJ (J = 0, 1, 2, 3, and 4). 相似文献
19.
Dr. Dawei Wen Hongmin Liu Zhe Ma Dr. Lei Zhou Junhao Li Dr. Yue Guo Prof. Qingguang Zeng Prof. Peter A. Tanner Prof. Mingmei Wu 《Angewandte Chemie (International ed. in English)》2023,62(35):e202307868
Orange Eu2+-doped phosphors are essential for light-emitting diodes for cornering lights to prevent fatal road accidents at night, but such phosphors require features of high thermal, chemical stability and facile synthesis. This study reports a series of yellow-orange-red emitting SrAl2Si3ON6:Eu2+ oxynitride phosphors, derived from the SrAlSi4N7 nitride iso-structure by replacing Si4+−N3− with Al3+−O2−. The introduction of a certain amount of oxygen enabled the facile synthesis under atmospheric pressure using the air-stable raw materials SrCO3, Eu2O3, AlN and Si3N4. SrAl2Si3ON6 has a smaller band gap and lower structure rigidity than SrAlSi4N7 (5.19 eV vs 5.50 eV, Debye temperature 719 K vs 760 K), but exhibits higher thermal stability with 100 % of room temperature intensity remaining at 150 °C compared to 85 % for SrAlSi4N7. Electron paramagnetic resonance, thermoluminescence and density functional theory revealed that the oxygen vacancy electron traps compensated the thermal loss. Additionally, no decrease in emission intensity was found after either being heated at 500 °C for 2 hours or being immersed in water for 20 days, implying both of the thermal and chemical stability of SrAl2Si3ON6:Eu2+ phosphors. The strategy of oxynitride-introduction from nitride promotes the development of low-cost thermally and chemically stable luminescent materials. 相似文献
20.
Jin Young Park Hong Chae Jung G. Seeta Rama Raju Byung Kee Moon Jung Hyun Jeong Jung Hwan Kim 《Solid State Sciences》2010,12(5):719-724
A series of Eu3+ ions co-doped (Gd0.9Y0.1)3Al5O12:Bi3+, Tb3+ (GYAG) phosphors have been synthesized by means of solvothermal reaction method. The XRD pattern of GYAG phosphor sintered at 1500 °C confirms their garnet phase. The luminescence properties of these phosphors have been explored by analyzing their excitation and emission spectra along with their decay curves. The excitation spectra of the GYAG:Bi3+, Tb3+, Eu3+ phosphors consists of broad bands in the shorter wavelength region due to 4f8 → 4f75d1 transition of Tb3+ ions overlapped with 6s2 → 6s16p1 (1S0 → 3P1) transition of Bi3+ ions and the charge transfer band of Eu3+–O2?. The present phosphors exhibit green and red colors due to 5D4 → 7F5 transition of Tb3+ ions and 5D0 → 7F1 transition of Eu3+ ions, respectively. The emission was shifted from green to red color by co-doping with Eu3+ ions, which indicate that the energy transfer probability from Tb3+ to Eu3+ ions are dependent strongly on the concentration of Eu3+ ions. 相似文献