共查询到20条相似文献,搜索用时 31 毫秒
1.
Eu2+‐doped magnesium haloborate Mg3B7O13Cl was synthesized by the conventional high‐temperature solid‐state reaction. The phase formation was confirmed by X‐ray powder diffraction (XRD) measurements and structure refinement. The photoluminescence excitation and emission spectra, and decay curves were measured. Under the excitation of near‐UV light, Eu2+‐doped Mg3B7O13Cl presents a narrow blue‐emitting band centered at 423 nm. The maximum absolute quantum efficiency (QE) of Mg3B7O13Cl:Eu2+ phosphor was measured to be 80% excited at 385 nm light at 300 K. The thermal stability of the blue luminescence was evaluated by the luminescence decays as a function of temperature. The phosphor shows an excellent thermal stability on temperature quenching effects. Moreover, Mg3B7O13Cl:Eu2+ phosphor shows scintillation characteristics excited by X‐ray irradiation at room temperature and presents a blue luminescence band with a fast lifetime of 600 ns. 相似文献
2.
Phase Transformation in Ca3(PO4)2:Eu2+ via the Controlled Quenching and Increased Eu2+ Content: Identification of New Cyan‐Emitting α‐Ca3(PO4)2:Eu2+ Phosphor
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Haipeng Ji Zhaohui Huang Zhiguo Xia Maxim S. Molokeev Mingyue Chen Victor V. Atuchin Minghao Fang Yan'gai Liu Xiaowen Wu 《Journal of the American Ceramic Society》2015,98(10):3280-3284
A case of phosphor is reported where the cooling rate parameter significantly influences the luminescence property. By quenching the sample after the high‐temperature solid‐state reaction at 1250°C, we successfully prepared the Eu2+‐doped α form Ca3(PO4)2 (α‐TCP:Eu2+) as a new kind of bright cyan‐emitting phosphor. The unusual emission color variation (from cyan to blue) depends on the cooling rate after sintering and Eu2+ doping level as it was observed in the TCP‐based phosphors. By the Rietveld analysis, it is revealed that the cyan‐ and blue‐emitting phosphors are two different TCP forms crystallizing in the monoclinic (space group P21/a, α‐TCP) and the rhombohedral structure (space group R3c, β‐TCP), respectively. Upon 365 nm UV light excitation, α‐TCP:Eu2+ exhibits an asymmetric broad‐band cyan emission peaking at 480 nm, while β‐TCP:Eu2+ displays a relatively narrow‐band blue emission peaking at 416 nm. The Eu2+‐doping in Ca3(PO4)2 shifts the upper temperature limit of the stable structural range of β form from 1125°C to ≥1250°C. Moreover, the crystal structures of α/β‐TCP:Eu2+ were compared in the aspects of compactness and cation site sets. The emission thermal stability of α/β‐TCP:Eu2+ was comparatively characterized and the difference was related to the specific host structural features. 相似文献
3.
Chuanxiang Qin Yanlin Huang Hyo Jin Seo 《Journal of the American Ceramic Society》2013,96(4):1181-1187
The new red‐emitting phosphors of Eu3+‐doped triple orthovanadates NaALa(VO4)2 (A = Ca, Sr, Ba) were prepared by the high‐temperature solid‐state reaction. The formation of single phase compound with isostructural structure of Ba3(VO4)2 was verified through X‐ray diffraction (XRD) studies. The photoluminescence excitation and emission spectra, the fluorescence decay curves and the dependence of luminescence intensity on doping level were investigated. The phosphor can be efficiently excited by near UV and blue light to realize an intense red luminescence (613 nm) corresponding to the electric dipole transition 5D0→7F2 of Eu3+ ions. Their potential applications as red‐emitting phosphors for solid‐state lighting were evaluated in comparison with the Eu3+‐doped lanthanum orthovanadate LaVO4 and other reported references. The luminescence was discussed in detail on the base of the crystal structures. The luminescence thermal stability on temperature was investigated and the thermal activated energy was calculated. The phosphors can be suggested to be a potential red‐emitting phosphor for the application on white LEDs under irradiation of near‐UV or blue chips. 相似文献
4.
Using the conventional high temperature solid‐state reaction method Ba2Ca(PO4)2:Eu2+ phosphors were prepared. The phase structure, photoluminescence (PL) properties, and the PL thermal stability of the samples were investigated, respectively. Under the excitation at 365 nm, the phosphor exhibited an asymmetric broad‐band blue emission with peak at 454 nm, which is ascribed to the 4f–5d transition of Eu2+. It was further proved that the dipole–dipole interactions results in the concentration quenching of Eu2+ in Ba2Ca1?x (PO4)2:xEu2+ phosphors. When the temperature turned up to 150°C, the emission intensity of Ba2Ca0.99(PO4)2:0.01Eu2+ phosphor was 59.07% of the initial value at room temperature. The activation energy ΔE was calculated to be 0.30 eV, which proved the good thermal stability of the sample. All the properties indicated that the blue‐emitting Ba2Ca(PO4)2:Eu2+ phosphor has potential application in white LEDs. 相似文献
5.
Ruijin Yu Hongjuan Li Hailong Ma Caifeng Wang Huan Wang 《Journal of the American Ceramic Society》2014,97(4):1151-1156
Blue‐emitting phosphor of Ce3+‐activated fluorosilicate apatite Ba2Y3[SiO4]3F was prepared via conventional solid‐state reaction method. The X‐ray powder diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) excitation and emission spectra, and the decay curves (lifetimes) were applied to characterize the phosphors. The effects of Ce3+ activator concentration on the luminescence properties were investigated. Ba2Y2.85Ce0.15[SiO4]3F exhibits the brightest blue emission with CIE coordinates of (x = 0.231, y = 0.301). The crystallographic site of Ce3+ ions in Ba2Y3[SiO4]3F lattices was identified. Two kinds of crystallographic Ce3+ occupying MI and MII sites in Ba2Y3[SiO4]3F lattices result in two distinct emission centers. The internal PL quantum efficiency, the temperature‐dependent luminescence, and the activation energy of thermal quenching were investigated to evaluate the potential application. This is a new kind of blue‐emitting phosphor based on apatite structure. 相似文献
6.
Hongde Xie Taiju Tsuboi Wei Huang Yanlin Huang Lin Qin Hyo Jin Seo 《Journal of the American Ceramic Society》2014,97(5):1434-1441
Nondoped and 5.0 mol% Eu3+‐doped vanadate garnets Ca5Mg4(VO4)6, NaCa2Mg2[VO4]3, KCa2Mg2[VO4]3, and NaSr2Mg2[VO4]3 were synthesized by solid‐state reactions. The formation of single‐phase compound with garnet structure is confirmed by X‐ray diffraction. The photoluminescence (PL) and PL excitation (PLE) spectra are investigated together with color coordinates. The luminescence process is discussed on the charge‐transfer transitions in [VO4]3? ions and the crystal structure. The PL quantum efficiencies (QE) are measured for nondoped and Eu3+‐doped samples. The Eu3+‐doped samples have higher QEs than the corresponding nondoped ones although the energy transfer occurs from [VO4]3? to Eu3+. Broad emission band due to [VO4]3? with intense sharp lines due to Eu3+, which gives white color, is observed in Eu3+‐doped NaCa2Mg2[VO4]3 and NaSr2Mg2[VO4]3 under excitation with UV light. These materials are suggested to be useful for lighting under the excitation with near‐UV LED. 相似文献
7.
Enhanced Luminescence in the SrMgAl10O17: Eu2+ Blue Phosphor Prepared by a Hybrid Urea‐Sol Combustion Route
下载免费PDF全文
![点击此处可从《International Journal of Applied Ceramic Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Le Wang Hong Zhang YangHui Li Pei Liang Ye Shen Feng Jiao 《International Journal of Applied Ceramic Technology》2016,13(1):185-190
A phase‐pure and high‐brightness blue phosphor, Eu2+ doped SrMgAl10O17 (SAM), was synthesized through a hybrid urea‐sol combustion route. The structure, photoluminescence spectra, and thermal stability of the SAM were investigated in this work. The phosphor had a homogeneous and rod‐like microstructure, showing a broad emission band centered at 465 nm under the 330 nm excitation. The concentration for luminescence quenching of SAM: Eu2+ occurred at 10 mol%, which doubled that of the phosphor prepared by the conventional combustion method. Compared with the traditional combustion method, the hybrid route led to improvements in luminescence by 52.2%, external quantum efficiency by 16.2%, and thermal stability by 8.8% at 435 K. The blue phosphor prepared by the new method could thus be potentially used with near ultraviolet light‐emitting diodes. 相似文献
8.
Synthesis and luminescence properties of single‐component Ca5(PO4)3F:Dy3+, Eu3+ white‐emitting phosphors
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Meng Yu Wentao Zhang Shiyu Qin Junfeng Li Kehui Qiu 《Journal of the American Ceramic Society》2018,101(10):4582-4590
A series of Ca5(PO4)3F:Dy3+, Eu3+ phosphors was synthesized by a solid‐state reaction method. The XRD results show that all as‐prepared Ca5(PO4)3F:Dy3+, Eu3+ samples match well with the standard Ca5(PO4)3F structure and the doped Dy3+ and Eu3+ ions have no effect on the crystal structure. Under near‐ultraviolet excitation, Dy3+ doped Ca5(PO4)3F phosphor shows blue (486 nm) and yellow (579 nm) emissions, which correspond to 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions respectively. Eu3+ co‐doped Ca5(PO4)3F:Dy3+ phosphor shows the additional red emission of Eu3+ at 631 nm, and an improved color rendering index. The chromaticity coordinates of Ca5(PO4)3F:Dy3+, Eu3+ phosphors also indicate the excellent warm white emission characteristics and low correlated color temperature. Overall, these results suggest that the Ca5(PO4)3F:Dy3+, Eu3+ phosphors have potential applications in warm white light‐emitting diodes as single‐component phosphor. 相似文献
9.
Zhichao Liu Lei Zhao Wenbo Chen Shuangyu Xin Xiaotong Fan Wenjuan Bian Xue Yu Jianbei Qiu Xuhui Xu 《Journal of the American Ceramic Society》2018,101(8):3480-3488
The thermal quenching properties and mechanisms of phosphors employed in white light emitting diodes (wLEDs) are critical for their commercial application. Here, we attempted to characterize the deep traps for capturing and releasing carriers to improve the thermal stability of the blue‐emitting CaAl2O4: Eu2+, Tm3+ phosphors. The enhanced thermal stability contributed to the introduction of traps has been demonstrated, and the mechanism of the transport process of carriers, has been explored in detail. In comparison with Eu2+ doped sample, the co‐doped Tm3+ samples bring more deep traps. The releasing of carriers in deep traps therefore sustains the luminescence with increasing temperature and compensates the thermal luminescence intensity loss. The results provide a theoretical basis and new field of view for exploring excellent thermal stability phosphors for wLEDs. 相似文献
10.
A single‐phase full‐color emitting phosphor Na3Sc2(PO4)3:Eu2+/Tb3+/Mn2+ with near‐zero thermal quenching and high quantum yield for near‐UV converted warm w‐LEDs
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dong Liu Yahong Jin Yang Lv Guifang Ju Chuanlong Wang Li Chen Weiwei Luo Yihua Hu 《Journal of the American Ceramic Society》2018,101(12):5627-5639
A single‐phase full‐color emitting phosphor Na3Sc2(PO4)3:Eu2+/Tb3+/Mn2+ has been synthesized by high‐temperature solid‐state method. The crystal structure is measured by X‐ray diffraction. The emission can be tuned from blue to green/red/white through reasonable adjustment of doping ratio among Eu2+/Tb3+/Mn2+ ions. The photoluminescence, energy‐transfer efficiency and concentration quenching mechanisms in Eu2+‐Tb3+/Eu2+‐Mn2+ co‐doped samples were studied in detail. All as‐obtained samples show high quantum yield and robust resistance to thermal quenching at evaluated temperature from 30 to 200°C. Notably, the wide‐gamut emission covering the full visible range of Na3Sc2(PO4)3:Eu2+/Tb3+/Mn2+ gives an outstanding thermal quenching behavior near‐zero thermal quenching at 150°C/less than 20% emission intensity loss at 200°C, and high quantum yield‐66.0% at 150°C/56.9% at 200°C. Moreover, the chromaticity coordinates of Na3Sc2(PO4)3:Eu2+/Tb3+/Mn2+ keep stable through the whole evaluated temperature range. Finally, near‐UV w‐LED devices were fabricated, the white LED device (CCT = 4740.4 K, Ra = 80.9) indicates that Na3Sc2(PO4)3:Eu2+/Tb3+/Mn2+ may be a promising candidate for phosphor‐converted near‐UV w‐LEDs. 相似文献
11.
Preparation,luminescence properties and energy transfer of Ca9Y(PO4)7: Eu2+‐Tb3+ phosphors
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Miao Tang Yanting Fan Zhongxian Qiu Jilin Zhang Liping Yu Chengzhi Li Shixun Lian Wenli Zhou 《Journal of the American Ceramic Society》2017,100(7):2991-2996
Tb3+‐doped and Eu2+, Tb3+ co‐doped Ca9Y(PO4)7 phosphors were synthesized by conventional solid‐state method. Additionally, the luminescence properties, decay behavior and energy transfer mechanism have already been investigated in detail. The green emission intensity of Tb3+ ions under NUV excitation is weak due to its spin‐forbidden f‐f transition. While Eu2+ can efficiently absorb NUV light and yield broad blue emission, most of which can be absorbed by Tb3+ ions. Thus, the emission color can be easily tuned from cyan to green through the energy transfer of Eu2+→Tb3+ in Ca9Y(PO4)7:Eu2+,Tb3+ phosphor. In this work, the phenomenon of cross‐relaxation between 5D3 and 5D4 are also mentioned. The energy transfer is confirmed to be resulted from a quadrupole‐quadrupole mechanism. 相似文献
12.
Structure and Luminescence Characteristics of Eu3+‐Activated Trigonal Layered Perovskite Ba2La2ZnW2O12
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Ruijin Yu Mengxue Li Nannan Xie Ting Wang Na Xue 《Journal of the American Ceramic Society》2015,98(12):3849-3855
Eu3+‐doped tungstate Ba2La2ZnW2O12 phosphors with perovskite‐structure were prepared by the high temperature solid‐state reaction. The X‐ray powder diffraction (XRD) patterns and structure refinements indicate that the phosphors crystalized in the trigonal layer‐perovskite. The luminescence properties of the phosphors were investigated such as photoluminescence (PL) excitation and emission spectra, decay lifetimes, and color coordinates. It was found that the pure host shows self‐activated emission excited by the UV light. Moreover, Ba2La2ZnW2O12 also shows scintillation characteristics under the X‐ray irradiation. The near‐UV and blue light can efficiently excite Eu3+‐doped Ba2La2ZnW2O12 phosphors inducing the strong orange–red luminescence. The optimal Eu3+ doping concentration in this host is 40 mol%. The luminescence spectra and the luminescence color of the phosphors strongly depend on the doping levels and excitation wavelength. The different luminescence features were discussed on the base of crystal structure. Eu3+ ions have two possible substitutions on A or B sites in this trigonal layered perovskite. The phosphor could act as a candidate for the potential application in near‐UV excited white‐LEDs lighting. 相似文献
13.
Hongde Xie Luyang Chen Chen Yuan Peiqing Cai Sun Il Kim Hyo Jin Seo 《Journal of the American Ceramic Society》2014,97(10):3216-3222
Eu3+‐doped cesium barium borate glass with the composition of Cs2O·2BaO·3B2O3 was prepared by the conventional melt quenching method. The glass‐ceramic sample was obtained from the re‐crystallization of the as‐made glass to change the amorphous glass into a crystalline host. This reduces the Eu3+ in glass to Eu2+ ions resulting in a yellow‐emitting phosphor of Eu2+‐activated CsBaB3O6. The samples were investigated by the XRD patterns and SEM micrograph, the optical absorption, the photoluminescence spectra, and decay curves. The as‐made glass has only Eu3+ centers. Under the excitation of blue or near‐UV light, Eu2+‐doped CsBaB3O6 presents yellow‐emitting color from the allowed inter‐configurational 4f–5d transition in the Eu2+ ions. The maximum absolute luminescence quantum efficiencies of Eu2+‐doped CsBaB3O6 phosphor was measured to be 47% excited at 430 nm light at 300 K. By taking into account the efficient excitation in blue wavelength region, this new phosphor could be a potential yellow‐emitting phosphor for an application in white light‐emitting diodes fabricated with blue chips. 相似文献
14.
Investigation of optical properties: Eu with Al codoping in aluminum silicate glasses and glass‐ceramics
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Eu‐doped transparent oxyfluoride aluminosilicate glass was prepared by controlling with Al codoping of melt‐quenched glass fabricated under air atmosphere. In the presence of Al input, the photoluminescence emission spectra under 393 nm excitation shows a blue shift by adjusting the ratio of Eu3+ and Eu2+. After heat treatment of glass, the ratio of Eu3+ and Eu2+ of luminescence emission were changed by controlling treatment temperature. The PL intensity of Eu3+ and Eu2+ ions in the glass‐ceramics (GC) was much stronger than in the precursor glass (PG). The possible mechanism responsible for color tuneability of the ratio of Eu3+ and Eu2+ doped was discussed. 相似文献
15.
Crystal structure and luminescence properties of a single‐component white‐light‐emitting phosphor Ca8ZnLa(PO4)7:Eu2+,Mn2+
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Ruiyu Mi Yan‐gai Liu Lefu Mei Chenglong Zhao Jian Chen Zhaohui Huang Minghao Fang 《Journal of the American Ceramic Society》2017,100(7):3050-3060
A series of novel green emission Whitlockite‐type Ca8ZnLa(PO4)7:Eu2+ and color tunable Ca8ZnLa(PO4)7:Eu2+,Mn2+ phosphors were prepared by the solid‐state reaction method in a reducing atmosphere. Its crystal structure and phase composition were identified by high‐resolution transmission electron microscopy, selected area electronic diffraction, X‐ray photoelectron spectroscopy, and X‐ray powder diffraction Rietveld refinement, and it was found to be trigonal, belonging to R‐3c(161) space group. The luminescence properties of Eu2+ singly doped and Eu2+/Mn2+ codoped Ca8ZnLa(PO4)7 phosphors were revealed in detail. Ca8ZnLa(PO4)7:Eu2+ is excitable over a broad range from 200 to 450 nm with a prominent green emitting. With varied Eu2+/Mn2+ ratios, fine‐tune emission under 365 nm excitation can be achieved from green (0.221, 0.468) to magenta (0.391, 0.276), especially the warm white light (0.392, 0.352), and CCT 3500 K can be obtained by the process of energy transfer between Eu2+ and Mn2+. The ET mechanism in this system is managed via the dipole‐dipole interaction with the maximum energy‐transfer efficiency 82.8% based on the decay lifetime data. These results suggest that as‐prepared phosphors can serve as promising candidates of UV‐pumped w‐LEDs. 相似文献
16.
A novel dazzling Eu3+‐doped whitlockite‐type phosphate red‐emitting phosphor for white light‐emitting diodes
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Li Li Xiaohua Tang Yifei Zheng Zhaojie Wu Wenxuan Chang Sha Jiang Guotao Xiang Xianju Zhou 《Journal of the American Ceramic Society》2018,101(9):4095-4107
A series of novel red‐emitting Ca8ZnLa1?xEux(PO4)7 phosphors were successfully synthesized using the high‐temperature solid‐state reaction method. The crystal structure, photoluminescence spectra, thermal stability, and quantum efficiency of the phosphors were investigated as a function of Eu3+ concentration. Detailed analysis of their structural properties revealed that all the phosphors could be assigned as whitlockite‐type β‐Ca3(PO4)2 structures. Both the PL emission spectra and decay curves suggest that emission intensity is largely dependent on Eu3+ concentration, with no quenching as the Eu3+ concentration approaches 100%. A dominant red emission band centered at 611 nm indicates that Eu3+ occupies a low symmetry sites within the Ca8ZnLa(PO4)7 host lattice, which was confirm by Judd‐Ofelt theory. Ca8ZnLa1?xEux(PO4)7 phosphors exhibited good color coordinates (0.6516, 0.3480), high color purity (~96.3%), and high quantum efficiency (~78%). Temperature‐dependent emission spectra showed that the phosphors possessed good thermal stability. A white light‐emitting diode (LED) device were fabricated by integrating a mixture of obtained phosphors, commercial green‐emitting and blue‐emitting phosphors into a near‐ultraviolet LED chip. The fabricated white LED device emits glaring white light with high color rendering index (83.9) and proper correlated color temperature (5570 K). These results demonstrate that the Ca8ZnLa1?xEux(PO4)7 phosphors are a promising candidate for solid‐state lighting. 相似文献
17.
Far‐Red‐Emitting BiOCl:Eu3+ Phosphor with Excellent Broadband NUV‐Excitation for White‐Light‐Emitting Diodes
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Yongjin Li Zongyan Zhao Zhiguo Song Ronghua Wan Jianbei Qiu Zhengwen Yang Zhaoyi Yin Xuee Liu Qun Liu Yuting Zhou 《Journal of the American Ceramic Society》2015,98(7):2170-2176
Rare‐earth ion‐doped semiconducting phosphor has attracted extensive attention due to the ability to achieve efficient luminescence through the host sensitization. Here, we present a new type red‐emitting Eu3+ ‐doped BiOCl phosphors possessing a broad excitation band in the near‐ultraviolet (NUV) region. Experimental measurements and theoretical calculations confirm that Eu3+ ion dopants result in forming impurity energy level near valence band, and the excellent broadband NUV‐exciting ability of Eu3+ ion is due to the electronic transitions of BiOCl band gap. Moreover, the highest emission intensity of the phosphors is from the 5D0 → 7F4 transition of Eu3+ around 699 nm (far‐red) through whether host excitation or direct Eu3+ ions excitation, which lie in the particular structure of BiOCl crystals. Our results indicate that the Eu3+ ‐doped BiOCl crystals show great potential as red phosphors for white‐light‐emitting diodes. 相似文献
18.
《Ceramics International》2017,43(12):8824-8830
A series of Eu2+ and Mn2+ co-doping Sr3GdLi(PO4)3F phosphors have been synthesized through high temperature solid state reaction. Eu2+ single doped Sr3GdLi(PO4)3F phosphors have an efficient excitation in the range of 230–430 nm, which is in good agreement with the commercial near-ultraviolet (n-UV) LED chips, and gives intense blue emission centering at 445 nm. The critical distance of the Eu2+ ions in Sr3GdLi(PO4)3F is computed and demonstrated that the concentration quenching mechanism of Eu2+ is mostly caused by the dipole-dipole interaction. By co-doping Eu2+ and Mn2+ ions in the Sr3GdLi(PO4)3F host, the energy transfer from Eu2+ to Mn2+ that can be discovered. With the increase of Mn2+ content, emission color can be adjusted from blue to white under excitation of 380 nm, corresponding to chromatic coordinates change from (0.189, 0.108) to (0.319, 0.277). The energy transfer from Eu2+ to Mn2+ ions is proven to be a dipole-dipole mechanism on the basis of the experimental results and analysis of photoluminescence spectra and decay curves. This study infers that the obtained Sr3GdLi(PO4)3F:Eu2+, Mn2+ phosphors may be a potential candidate for n-UV LEDs. 相似文献
19.
Xiao‐Jun Wang Benjamin Dierre Takashi Takeda Naoto Hirosaki Takashi Sekiguchi Huili Li Zhuo Sun 《Journal of the American Ceramic Society》2014,97(2):339-341
Eu2+‐doped AlN‐polytypoids (8H, 15R, 12H, and 21R) were successfully synthesized by nitrogen‐gas‐pressure sintering. The phosphors show intense blue emissions under the electron beam excitation. All the polytypoid phosphors exhibit relatively a smaller degradation in luminance and a higher thermal stability in comparison to the oxide counterparts. Among the polytypoids, 12H has no luminance saturation, and shows a brightness of 40 cd/m2 at 3 kV and 100 μA. These results indicate that Eu2+‐doped AlN‐polytypoids could also be used as blue phosphors for FEDs. 相似文献
20.
New single‐component multicolor emission Na1−xAl1+2xSi1−2xO4:xBi3+/Eu3+ phosphors via energy transfer
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Chengyi Xu Ye Sheng Yanhua Song Hongxia Guan Xiangting Zhang Deyue Meng He Zhu Zhan Shi Haifeng Zou Keyan Zheng 《Journal of the American Ceramic Society》2018,101(6):2353-2367
A series of emission‐tunable Na1?xAl1+2xSi1?2xO4:xBi3+/Eu3+ phosphors were synthesized via high temperature solid‐state reaction method. The luminescence properties, energy transfer from Bi3+ to Eu3+ ions, color tuning, thermal stability and quantum efficiency were systematically investigated. Especially, in the host, a certain amount of Si4+ were replaced by Al3+ in order to remedy the charge compensating defect, so that, the emission intensity had been improved. The results of Rietveld refinements, the analysis of SEM mapping and the fourier transform infrared (FT‐IR) indicated that this charge balance strategy was an effective method. Meanwhile, the energy transfer from Bi3+ to Eu3+ can be inferred and confirmed and the mechanisms were demonstrated to quadrupole–quadrupole interaction. The emission hue can be tuned from blue to pink, and finally to orange red light by properly varying the ratio of Bi3+ and Eu3+. Importantly, when the temperature was raised to 150°C, the integrated emission intensity was 71.20% of the initial value for NAS:1%Bi3+,2%Eu3+ samples indicating that these phosphors had excellent thermal stability and stable color (no emission shift). All these properties indicate that the developed phosphors may be potentially used as single‐component color‐tunable‐emitting phosphors for UV light‐emitting diodes. 相似文献