共查询到20条相似文献,搜索用时 0 毫秒
1.
The effects of charge compensation on photoluminescence properties of a new green‐emitting ZnB2O4:Tb3+ phosphor
下载免费PDF全文
![点击此处可从《Luminescence》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jie Liu Zhan‐Chao Wu Ping Wang Yong‐Mei Mei Man Jiang Shao‐Ping Kuang 《Luminescence》2014,29(7):868-871
Charge compensation is an effective way to eliminate charge defects and improve the luminescent intensity of phosphors. In this paper, a new green‐emitting phosphor ZnB2O4:Tb3+ was prepared by solid‐state reaction at 750°C. The effects of Tb3+ doping content and charge compensators (Li+, Na+ or K+) on photoluminescence properties of ZnB2O4:Tb3+ were investigated. X‐ray powder diffraction analysis confirms the sample has cubic structure of ZnB2O4. The excitation and emission spectra indicate that this phosphor can be excited by near ultraviolet light at 378 nm, and exhibits bright green emission with the highest peak at 544 nm corresponding to the 5D4→7F5 transition of Tb3+. The critical quenching concentration of Tb3+ in ZnB2O4 host is 8 mol%. The results of charge compensation show that the emission intensity can be improved by Na+ and K+. Specifically, K+ is the optimal one for ZnB2O4:Tb3+. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
2.
LaBSiO5 phosphors doped with Ce3+ and Tb3+ were synthesized using the conventional solid‐state method at 1100 °C. The phase purity and luminescent properties of these phosphors are investigated. LaBSiO5:Tb3+ phosphors show intense green emission, and LaBSiO5 phosphors doped with Ce3+ show blue–violet emission under UV light excitation. LaBSiO5 phosphors co‐doped with Ce3+ and Tb3+ exhibit blue–violet and green emission under excitation by UV light. The blue–violet emission is due to the 5d–4f transition of Ce3+ and the green emission is ascribed to the 5D4 → 7 F5 transition of Tb3+. The spectral overlap between the excitation band of Tb3+ and the emission band of Ce3+ supports the occurrence of energy transfer from Ce3+ to Tb3+, and the energy transfer process was investigated. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
3.
A series of color‐tunable Ca3–2x‐y‐zSiO4Cl2 (CSC):xCe3+,xLi+,yMn2+,zEu2+ phosphors with low temperature phase structure was synthesized via the sol–gel method. An energy transfer process from Ce3+ to Mn2+ in CSC:0.01Ce3+,0.01Li+,yMn2+ (y = 0.03–0.09) and the mechanism was verified to be an electric dipole–dipole interaction. The Ce3+ and Mn2+ emission intensities were greatly enhanced by co‐doping Eu2+ ions into CSC:0.01Ce3+,0.01Li+,0.07Mn2+ phosphors due to competitive energy transfers from Eu2+/Ce3+ to Mn2+, and Ce3+ to Eu2+. Under 332 nm excitation, CSC:0.01Ce3+,0.01Li+,0.07Mn2+,zEu2+ (z = 0.0005–0.002) exhibited tunable emission colors from green to white with coexisting orange, green and violet‐blue emissions. These phosphors could have potential application in white light‐emitting diodes. 相似文献
4.
White-light-tunable LaMgAl11O19:x%Tb3+, y%Eu3+ series phosphors were prepared using the gel-combustion method. The structure and luminescence properties were studied, and the energy transfer of Eu3+ and Tb3+ in the LaMgAl11O19 system was also discussed. The results showed that the LaMgAl11O19 matrix exhibited strong emission in the blue-light region under the excitation of ultraviolet light, which resulted in conditions suitable for the preparation of white-light-tunable phosphors. The emission spectra of LaMgAl11O19:2%Tb3+, y%Eu3+ (y = 2%–9%) series phosphors were obtained through optimization experiments. It could be seen from the CIE diagram that by adjusting the doping quantities of Eu3+ and Tb3+ in the LaMgAl11O19 host, multicolor luminescence and white light emission in a single host could be achieved. By calculating the energy transfer efficiency and critical distance between Eu3+ and Tb3+ series phosphors, the mechanism of energy transfer between Tb3+ and Eu3+ was found to be the interaction between electric quadruples. 相似文献
5.
Mantwa Annah Lephoto Kamohelo George Tshabalala Selepe Joel Motloung Samy Khalil Kamel Shaat Odireleng Martin Ntwaeaborwa 《Luminescence》2017,32(6):1084-1091
Europium (Eu3+) and bismuth (Bi3+) co‐activated LiBaBO3 powder phosphors were synthesized by a solid‐state reaction and the structure, particle morphology, optical and photoluminescent properties were investigated. X‐Ray diffraction patterns of the LiBaBO3 phosphors crystallized in a pure monoclinic phase, i.e. there were no secondary phases due to either incidental impurities or undecomposed starting materials. Scanning electron microscopy images showed that the powders were made up of fluffy needle‐like particles that were randomly aligned. The band‐gap of the LiBaBO3 host was estimated to be 3.33 eV from the UV/vis absorption data. Blue emission was observed from the LiBaBO3 host, which is ascribed to self‐activation of the host matrix. In addition, greenish‐blue (493 nm) and red (613 nm) emissions were observed from europium‐doped samples and were attributed to the emissions of Eu2+ and Eu3+, respectively. Furthermore, after codoping with Bi3+, the emission intensity of Eu3+ located at 613 nm was significantly enhanced. From the Commission Internationale de I′Eclairage (CIE) color coordinates, white emission was observed from LiBa1–xBO3:xEu3+ (x = 0.020 and 0.025) phosphor powders with color coordinates of x = 0.368, y = 0.378 and x = 0.376, y = 0.366, respectively. 相似文献
6.
Eu3+,Dy3+ co-doped Sr2LaZrO5.5-based phosphors were prepared through a sol–gel method. Through characterization, it was found that the Sr2LaZrO5.5-based fluorescent powder co-doped with Eu3+ and Dy3+ had a cubic structure. At an excitation wavelength of 290 nm, the substrate Sr2LaZrO5.5 exhibited strong blue emission at 468 nm, and the Sr2LaZrO5.5:18%Eu3+ phosphor exhibited a strong red emission peak at 612 nm. When the doping amount of Dy3+ was 5, 8, 12, 15, or 18%, the Sr2LaZrO5.5:18%Eu3+ phosphor changed from an orange-red light, to a warm white light, and to a cold white light. According to the emission spectra, the emission intensities of the substrates Sr2LaZrO5.5 and Sr2LaZrO5.5:Eu3+ decreased with increasing Dy3+ concentration, confirming the energy transfer between the host Sr2LaZrO5.5-Eu3+,Dy3+, and resulting in a lower CCT value, with significantly improved white light emission. 相似文献
7.
Huanhuan You Xiaoyu Huang Xingda Zhang Piaopiao Jin Zhaopeng Xu Jing Zhai Faming Gao Yongchao Jia 《Luminescence》2024,39(3):e4701
In the present work, a novel n-UV convertible colour-tunable emitting phosphor was obtained based on the efficient Ce3+-Tb3+ energy transfer in the Y10Al2Si3O18N4 host. By properly controlling the ratio of Ce3+/Tb3+, the colour hue of the obtained powder covered the blue and green regions, under excitation of 365 nm. The steady-state and dynamic-state luminescence measurement was performed to shed light on the related mechanism, which was justified by the electronic dipole–quadrupole dominating the related energy transfer process. Preliminary studies showed that Y10Al2Si3O18N4:Ce3+,Tb3+ can be promising as an inorganic phosphor for white LED applications. 相似文献
8.
Eu2+ and Tb3+ singly doped and co‐doped LaAl11O18 phosphors were prepared by a combustion method using urea as a fuel. The phase structure and photoluminescence (PL) properties of the prepared phosphors were characterized by powder X‐ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence excitation and emission spectra. When the content of Eu2+ was fixed at 0.01, the emission chromaticity coordinates could be adjusted from blue to green region by tuning the contents of Tb3+ ions from 0.01 to 0.03 through an energy transfer (ET) process. The fluorescence data collected from the samples with different contents of Tb3+ into LaAl11O18: Eu, show the enhanced green emission at 545 nm associated with 5D4 –7F5 transitions of Tb3+. The enhancement was attributed to ET from Eu2+ to Tb3+, and therefore Eu2+ ion acts as a sensitizer (an energy donor) while Tb3+ ion as an activator. The ET from Eu2+ to Tb3+ is performed through dipole–dipole interaction. The ET efficiency and critical distance were also calculated. The present Eu2+–Tb3+ co‐doped LaAl11O18 phosphor will have potential application for UV convertible white light‐emitting diodes. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
9.
Amit R. Bansod Abhijeet R. Kadam Prashant S. Bokare Sanjay J. Dhoble 《Luminescence》2022,37(8):1352-1360
Pyrochlore phosphors have shown their worth in modern day lighting in the last few years. Colour tunability of the phosphor is one of the modern techniques used to obtain white light-emitting diodes (WLEDs). In the proposed work, Y2Zr2O7:Sm3+,Eu3+ phosphors were investigated for WLED applications as well as display devices. A convectional solid-state diffusion method was used to synthesize the proposed phosphors. X-ray diffraction of the proposed phosphors was performed and compared with the standard Inorganic Crystal Structure Database. The crystal structure of the sample was cubic in nature, obtained from Rietveld refinement. Vibrational and morphological studies on the samples were carried out using Fourier transform infrared spectroscopy and scanning electron microscopy analysis. The photoluminescence study of the colour tunable phosphor showed the characteristic peak of Sm3+ together with the two sharp peaks of Eu3+ ions. Greenish yellow to red colour tunability was observed in the proposed phosphor with enhancement of Eu3+ ions. All these results showed the worth of this sample for WLEDs applications as well as in display devices. 相似文献
10.
An energy transfer process from Ce3+ to Tb3+ ions was successfully achieved in a Li2SO4–Al2(SO4)3 mixed‐sulphate system. A wet‐chemical synthesis was employed to prepare the Li2SO4–Al2(SO4)3 system by doping Ce3+ and Tb3+ ions individually as well as collectively. The phases were identified using X‐ray diffraction studies. The as‐prepared samples were characterized by FT‐IR and photoluminescence measurements. Green‐light emission was exhibited by Ce3+, Tb3+ co‐doped Li2SO4–Al2(SO4)3 system, thus, indicating its potential as a material for display devices or in the lamp industry. 相似文献
11.
Influence of rare earth elements (Y,Gd and Lu) on the luminescent properties of green phosphor ZnMoO4:Tb3+
下载免费PDF全文
![点击此处可从《Luminescence》网站下载免费的PDF全文](/ch/ext_images/free.gif)
(Zn,Lnx)MoO4:Tb3+ (Ln = Y3+, Gd3+ and Lu3+) were prepared using the co‐precipitation method. Phase impurity, morphology and composition were investigated by power X‐ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The experimental results show that crystal structure is not destroyed after doping an appropriate amount of Y3+, Gd3+ and Lu3+. EDS analysis reveals that Y, Gd and Lu have been successfully doped into ZnMoO4. In addition, the morphology of the phosphors is notably improved, exhibiting homogeneous dispersion morphology and irregular shapes of particle size ~ 0.5–1 µm. The luminescent intensity of (Zn,Lnx)MoO4:Tb3+ (Ln = Y3+, Gd3+ and Lu3+) phosphor is obviously higher than that of ZnMoO4:Tb3+ phosphor. The energy transfer process between trivalent rare earth ions indicates that the inert earth ions can act as an energy bridge from MoO42‐ to Tb3+. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
12.
Samirkumar R. Bhelave Abhijeet R. Kadam Atul N. Yerpude Sanjay J. Dhoble 《Luminescence》2023,38(4):379-388
This article focuses on the effect of monovalent cation doping on the optical properties of rare earth (RE = Eu3+, Tb3+) co-doped Ca14Zn6Al10O35 which has been synthesized by a low temperature combustion method. Crystalline phase of the Ca14Zn6Al10O35 phosphor was examined and confirmed by X-ray diffraction measurement. Under near-ultraviolet light excitation Eu3+-doped Ca14Zn6Al10O35 phosphor exhibit characterization of Eu3+ emission bands that are located at a maximum wavelength (λmax) of approximately 470 nm and other peaks centred at 593 nm and 615 nm, respectively. With Tb3+-doped Ca14Zn6Al10O35 phosphor showing a green emission band centred at 544 nm under near-ultraviolet range. Furthermore, we studied the energy transfer process in Eu3+/Tb3+pair and enhancement in photoluminescence (PL) intensity with doping different charge compensation. Here we obtained the optimum PL emission intensity of the phosphor in broad and intense visible spectral range which may be significant for the fabrication of white light emitting diodes (WLEDs). 相似文献
13.
Eu(2+), Dy(3+) and Tb(3+) co-doped strontium aluminate phosphor with high brightness and long afterglow was synthesized by a combustion method, using urea as a reducer. The properties of SrAl(2)O(4):Eu(2+),Dy(3+),Tb(3+) phosphor with a series of initiating combustion temperatures, urea concentrations and boric acid molar fractions were investigated. The sample at initiating combustion temperature of 600 degrees C exhibited an intense emission peak at 513 nm, in which the phosphor existed as a single-phase monoclinic structure. The experimental results showed that the optimum ratio of urea is 2.0 times higher than theoretical quantities and that the suitable molar fraction of H(3)BO(3) is 0.08. The average particle size of the phosphor was 50-80 nm and its luminescence properties were studied systematically. Compared with SrAl(2)O(4):Eu(2+),Dy(3+) phosphor, the initial luminescence brightness improved from 2.50 candela (cd)/m(2) to 3.55 cd/m(2) and the long afterglow time was prolonged from 1290 s to 2743 s. 相似文献
14.
This work presents the optimized luminescence spectra for the Ce3+,Sm3+-doped NaSrPO4 phosphor that was synthesized using a wet chemical method. Ce3+ and Sm3+ are activator impurities that show spectral splitting bands that corresponds to the d–f and f–f transitions, respectively. These impurity elements shows the characteristics spectral bands when doped with the NaSrPO4 host lattice. Spectral splitting in the Ce3+ excitation band was monitored in the 240–340 nm range, in which the observed bands were located at 269 nm, 292 nm and 321 nm, and emission bands were observed in the broad spectral range 330–430 nm. However, when Sm3+ ion was doped in the same host lattice we obtained a characteristic emission band at 590 and 645 nm in the orange–red region, under sharp excitation bands located at 345, 361, 375, and 403 nm respectively. Also, we carried out energy transfer analysis in the Ce3+/Dy3+-doped NaSrPO4 phosphor. Further crystalline phase and the nanophase nature of the phosphor compound were confirmed using X-ray diffraction and transmission electron microscopy analyses. 相似文献
15.
An inorganic NaMgSO4F fluoride material was prepared by the wet chemical method and studied for its photoluminescence (PL) and resonant–non‐resonant energy transfer (RET and NORET) capabilities between Ce3+ → Tb3+, Ce3+ → Eu3+ and Ce3+ → Dy3+ rare earth ions. The Tb3+ emission for Ce3+ → Tb3+ transfers under ultraviolet (UV) wavelengths peaked at 491, 547, and 586 nm, for excitation at 308 nm due to 5D4 → 7FJ (J = 4, 5, 6) transitions. Eu emission spectra were observed at 440 nm (Eu2+), 593 nm and 616 nm (Eu3+) recorded for different concentrations of materials, whereas Dy3+ emission from Ce3+ → Dy3+ transfer under UV wavelengths peaked at 485 nm and 577 nm due to 4F9/2 → 6H15/2 and 6H13/2 transitions. The purpose of the present study is to understand the RET and NORET effects of Tb3+, Eu3+ and Dy3+ co‐doping in a NaMgSO4F:Ce3+ luminescent material, which could be used as a green‐emitting material for lamp phosphors. 相似文献
16.
KNaSO4 microphosphor doped with Ce,Gd and Ce,Tb and prepared by a wet chemical method was studied using X‐ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) characterization. KNaSO4 has a 5‐µm particle size detected by SEM. KNaSO4:Ce3+,Tb3+ showed blue and green emission (at 494 nm, 557 nm, 590 nm) of Tb3+ due to 5D4 → 7FJ (J = 4, 5, 6) transitions. KNaSO4:Ce3+,Gd3+ showed luminescence in the ultraviolet (UV) light region at 314 nm for an excitation at 271 nm wavelength. It was observed that efficient energy transfer took place from Ce3+ → Gd3+ and Ce3+ → Tb3+ sublattices indicating that Ce3+ could effectively sensitize Gd3+ or Tb3+ (green emission). Ce3+ emission weakened and Gd3+ or Tb3+ enhanced the emission significantly in KNaSO4. This paper discusses the development and understanding of photoluminescence and the effect of Tb3+ and Gd3+ on KNaSO4:Ce3+. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
17.
Dual emission of Ce3+,Mn2+‐coactivated Ca3YNa(PO4)3F via energy transfer: a single component white/yellow‐emitting phosphor
下载免费PDF全文
![点击此处可从《Luminescence》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Anxiang Guan Chunying Yao Guofang Wang Anjie Fu Liya Zhou Yingbin Meng Qiuping Wang 《Luminescence》2017,32(4):529-534
A series of Ce3+,Mn2+‐coactivated Ca3YNa(PO4)3F phosphors were synthesized via a traditional solid‐state reaction under a reductive atmosphere. X‐Ray powder diffraction was used to confirm that the crystal structure and diffraction peaks of Ce3+/Mn2+‐doped samples matched well with the standard data. A spectral overlap between the emission band of Ce3+ and the excitation band of Mn2+ suggested the occurrence of energy transfer from Ce3+ to Mn2+. With increasing Mn2+ content, the emission intensities and lifetime values of the Ce3+ emission for Ca3YNa(PO4)3F:Ce3+,Mn2+ phosphors linearly decrease, whereas the energy transfer efficiencies gradually increase to 89.35%. By adjusting the relative concentrations of Ce3+ and Mn2+, the emission hues are tuned from blue to white and eventually to yellow. These results suggest that Ca3YNa(PO4)3F:Ce3+,Mn2+ phosphors have promising application as white‐emitting phosphors for near‐ultraviolet light‐emitting diodes. 相似文献
18.
This work reports the photoluminescence properties of Ca3Mg3(PO4)4:Sm3+ phosphors that were synthesized by the combustion method. The phase formation and morphology of the prepared phosphors were analysed by X‐ray diffraction studies and scanning electron microscopy. Ca3Mg3(PO4)4:Sm3+ phosphors give orange light emission when excited by near‐ultraviolet (NUV) and blue light. The photoluminescence characteristics of the as‐prepared phosphors were investigated and their emission spectra showed three peaks due to 4G5/2 → 6H5/2, 4G5/2 → 6H7/2 and 4G5/2 → 6H9/2 transitions. The mechanism responsible for the concentration quenching of luminescence was found to be an electric dipole–dipole interaction. The CIE chromaticity coordinates suggested that the prepared phosphors are potential candidates for orange light‐emitting diodes (LEDs). 相似文献
19.
Tirath Ram Neeraj Verma Jagjeet Kaur Abhishek Kumar Misra Vikas Dubey Neha Dubey Ankush Vij Myla Chimpiri Rao 《Luminescence》2023,38(9):1591-1596
Here, the synthesis and luminescence analysis of the Tb3+-activated phosphor were reported. The CaY2O4 phosphors were synthesized using a modified solid-state reaction method with a variable doping concentration of Tb3+ ion (0.1–2.5 mol%). As synthesized, the phosphor was characterized using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis techniques for the optimized concentration of doping ions. The prepared phosphor showed a cubic structure, and FTIR analysis confirmed functional group analysis. It was discovered that the intensity of 1.5 mol% was higher than at other concentrations after the photoluminescence (PL) excitation and emission spectra were recorded for different concentrations of doping ions. The excitation was monitored at 542 nm, and the emission was monitored at 237 nm. At 237 nm excitation, the emission peaks were found at 620 nm (5D4→7F3), 582 nm (5D4→7F4), 542 nm (5D4→7F5), and 484 nm (5D4→7F6). The 1931 CIE (x, y) chromaticity coordinates showed the distribution of the spectral region calculated from the PL emission spectra. The values of (x = 0.34 and y = 0.60) were very close to dark green emission. Therefore, the produced phosphor would be very useful for light-emitting diode (green component) applications. Thermoluminescence glow curve analysis for various concentrations of doping ions and various ultraviolet (UV) exposure times was carried out, and a single broad peak was found at 252°C. The computerized glow curve deconvolution method was used to obtain the related kinetic parameters. The prepared phosphor exhibited an excellent response to UV dose and could be useful for UV ray dosimetry. 相似文献
20.
Synthesis and luminescence characterization of Y2BaZnO5:RE (RE = Eu3+, Tb3+, Pr3+ and Sm3+) phosphors
下载免费PDF全文
![点击此处可从《Luminescence》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Modified synthesis and luminescence of Y2BaZnO5 phosphors activated with the rare earths (RE) Eu3+, Tb3+, Pr3+ and Sm3+ are reported. RE2BaZnO5 phosphors have attracted attention because of their interesting magnetic and optical properties; and are usually prepared using a two‐step solid‐state reaction. In the first step, carbonates or similar precursors are thoroughly mixed and heated at 900°C to decompose them to oxides. To eliminate the unwanted phases like BaRE2O4, the resulting powders are reheated at 1100°C for a long time. We prepared Y2BaZnO5 phosphors activated with various activators by replacing the first step with combustion synthesis. The photoluminescence results are presented. The photoluminescence results for Eu3+, Tb3+ and Pr3+ are in good agreement with the literature. However, photoluminescence emission from Sm3+ has not been documented previously. The excitation spectrum of Eu3+ is dominated by a charge transfer band around 261 nm, and an additional band around 238 nm is always present, irrespective of the type of activator. The presence of this band for all these different types of activators was interpreted as host absorption. 相似文献