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1.
Zheng Lu Dashuai Sun Zeyu Lyu Sida Shen Lixuan Wang Jianhui Wang Hanwei Zhao Hongpeng You 《Journal of the American Ceramic Society》2023,106(2):1182-1193
A novel apatite-type SrMgY3(SiO4)3F was synthesized by a high-temperature solid-state reaction. The crystal structure was refined using powder X-ray diffraction data. SrMgY3(SiO4)3F crystallizes in P63/m hexagonal space group with lattice parameters of a = b = 9.45270 Å, c = 6.77617 Å, and V = 524.357 Å3. The incorporation of the Ce3+ and Tb3+ ions into the matrix can generate bright blue and green lights under ultraviolet (UV) light excitation. The codoped Ce3+ and Tb3+ in SrMgY3(SiO4)3F can effectively improve green emission intensity and thermal stability through the energy transfer from the Ce3+ to Tb3+ ions. With the increase of Tb3+-doping content, the luminescent color of phosphor changes from blue to cyan and finally to green. SrMgY3(SiO4)3F:0.06Ce3+,0.90Tb3+ phosphor exhibited intense green light emission with a quantum yield of 59.49% and good thermal stability, with an emission intensity at 150°C was 96% of that at 30°C. Finally, the prepared sample was coated on 365 nm UV chips to fabricate white light-emitting diodes with a color rendering index of 82.6 and a correlated color temperature of 2912 K, demonstrating its potential for applications in display and lighting. 相似文献
2.
《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
3.
Dayu Huang Yi Wei Peipei Dang Xiao Xiao Hongzhou Lian Jun Lin 《Journal of the American Ceramic Society》2020,103(5):3273-3285
LaScO3:xBi3+,yTb3+,zEu3+ (x = 0 − 0.04, y = 0 − 0.05, z = 0 − 0.05) phosphors were prepared via high-temperature solid-state reaction. Phase identification and crystal structures of the LaScO3:xBi3+,yTb3+,zEu3+ phosphors were investigated by X-ray diffraction (XRD). Crystal structure of phosphors was analyzed by Rietveld refinement and transmission electron microscopy (TEM). The luminescent performance of these trichromatic phosphors is investigated by diffuse reflection spectra and photoluminescence. The phenomenon of energy transfer from Bi3+ and Tb3+ to Eu3+ in LaScO3:xBi3+,yTb3+,zEu3+ phosphors was investigated. By changing the ratio of x, y, and z, trichromatic can be obtained in the LaScO3 host, including red, green, and blue emission with peak centered at 613, 544, and 428 nm, respectively. Therefore, two kinds of white light-emitting phosphors were obtained, LaScO3:0.02Bi3+,0.05Tb3+,zEu3+ and LaScO3:0.02Bi3+,0.03Eu3+,yTb3+. The energy transfer was characterized by decay times of the LaScO3:xBi3+, yTb3+, zEu3+ phosphors. Moreover absolute internal QY and CIE chromatic coordinates are shown. The potential optical thermometry application of LaScO3:Bi3+,Eu3+ was based on the temperature sensitivity of the fluorescence intensity ratio (FIR). The maximum Sa and Sr are 0.118 K−1 (at 473.15 K) and 0.795% K−1 (at 448.15 K), respectively. Hence, the LaScO3:Bi3+,Eu3+ phosphor is a good material for optical temperature sensing. 相似文献
4.
Xiaoyi Fan Jiayong Si Mengjie Xu Guihua Li Jiamin Tang Gemei Cai 《Ceramics International》2021,47(9):12056-12065
The development of novel single-component white-emitting phosphors with high thermal stability is essential for improving the illumination quality of white light-emitting diodes. In this work, we synthesized a series of Ce3+, Tb3+, Mn2+ single- and multiple-doped Ca9La(PO4)7 (CLPO) phosphors with β-Ca3(PO4)2-type structure by the simple high-temperature solid-state reaction. The crystallization behavior, crystal structure, surface morphology, photoluminescence performance, decay lifetime and thermal stability were systematically investigated. The PL spectra and decay curves have evidenced the efficient energy transfer from Ce3+ to Tb3+ and from Ce3+ to Mn2+ in the CLPO host, and corresponding energy transfer efficiency reaches 41.8% and 54.1%, respectively. The energy transfer process of Ce3+→Tb3+ and Ce3+→Mn2+ can be deduced to the resonant type via dipole-dipole and dipole-quadrupole interaction mechanism, and corresponding critical distance were determined to be 12.23 and 14.4 Å, respectively. Based on the efficient energy transfer, the white light emission can be successfully achieved in the single-component CLPO:0.15Ce3+, 0.10Tb3+, 0.04Mn2+ phosphor, which owns CIE chromaticity coordinates of (0.3245, 0.3347), CCT of 5878 K, internal and external quantum efficiency of 84.51% and 69.32%. Especially, compared with the emission intensity at 25 °C, it still remains 98.5% at 150 °C and 92.0% at 300 °C. Based on these results, the single-component white light emission phosphor CLPO:0.15Ce3+, 0.10Tb3+, 0.04Mn2+ is a potential candidate for UV-converted white LEDs. 相似文献
5.
Synthesis and luminescence properties of single‐component Ca5(PO4)3F:Dy3+, Eu3+ white‐emitting phosphors
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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
6.
Zheng Lu Dashuai Sun Zeyu Lyu Sida Shen Pengcheng Luo Shuai Wei Luhui Zhou Hongpeng You 《Journal of the American Ceramic Society》2023,106(11):6617-6629
A series of LaCaGaO4:xBi3+,yEu3+ (x = 0.002–0.04, y = 0.02–0.45) phosphors with adjustable emission colors were synthesized by high-temperature solid-state reaction. The samples were identified as pure phases by X-ray diffraction and Rietveld refinement, and the crystal structures were analyzed in detail. The LaCaGaO4:xBi3+ phosphor shows an intense blue emission under near-ultraviolet excitation, originating from the 3P1 → 1S0 transition. The spectrum analysis reveals that the Bi3+ ions occupy two luminescence centers in the LaCaGaO4 host and that energy transfer can occur. A model of the energy transfer between the Bi3+ and Eu3+ ions was also created and studied in detail. As the Eu3+-concentration increased, the emission color of the LaCaGaO4:0.005Bi3+,yEu3+ phosphor changed from blue to pink to red. In addition, the fluorescence lifetime, quantum yield, thermal stability, and other properties of the phosphors were characterized and analyzed. Finally, two white light-emitting diode devices with Ra values of 96.6 and 95 and correlated color temperatures of 4578 and 3324 K were fabricated, indicating the potential of phosphors for warm white lighting applications. 相似文献
7.
Wei Chen Linli Shen Chenyang Shen Zelong Zhang Xiaojuan Liang Weidong Xiang 《Journal of the American Ceramic Society》2019,102(1):331-341
A double perovskite-type substrate of La2MgGeO6 (LMGO) was successfully synthesized via a high-temperature solid-state reaction method and was codoped with Mn4+ and Dy3+ to form a new deep-red phosphor (LMGO:Mn4+,Dy3+) for artificial plant growth light-emitting diodes (LEDs). This extraordinary phosphor can exhibit strong far-red emission with a maximum peak at 708 nm between 650 and 750 nm, which can be ascribed to the 2Eg → 2A2 g spin-forbidden transition of Mn4+. The X-ray diffraction (XRD) patterns and high-resolution transmission electron microscopy (HRTEM) clarified that the La3+ sites in the host were partly replaced by Dy3+ ions. Moreover, we discovered energy transfers from Dy3+ to Mn4+ by directly observing the significant overlap of the excitation spectrum of Mn4+ and the emission spectrum of Dy3+ as well as the systematic relative decline and growth of the emission bands of Dy3+ and Mn4+, respectively. With the increase in the activator (Mn4+) concentration, the relationship between the luminescence decay time and the energy transfer efficiency of the sensitizer (Dy3+) was studied in detail. Finally, an LED device was fabricated using a 460 nm blue chip, and the as-obtained far-red emitting LMGO:Mn4+,Dy3+ phosphors for Wedelia chinensis cultivation. As expected, the as-fabricated plant growth LED-treated Wedelia chinensis cultured in the artificial climate box with overhead LEDs demonstrated that after 28 days of irradiation, the average plant growth rate and the total chlorophyll content were better than those of specimens cultured using the commercial R-B LED lamps, indicating that the as-prepared phosphor could have a potential application in the agricultural industry. 相似文献
8.
《Ceramics International》2023,49(10):15341-15348
A series of Dy3+-activated Ba2La8(SiO4)6O2 phosphors were synthesized using the solid-state method with the objective of developing single host white light emitting phosphors for use in solid state lighting applications. The Dy3+ concentration varied between 0.01 and 0.05 mol%. The as-prepared phosphors crystal structure, optical, and photoluminescent properties (PL), along with energy transfer mechanism and luminescence decay, were investigated. The production of a single-phase Ba2La8(SiO4)6O2 with hexagonal symmetry was verified by the findings of the X-ray diffraction analysis. When the Ba2La8(SiO4)6O2: Dy3+ phosphors are exposed to ultraviolet light, they emit the characteristic yellow PL emissions caused by the 4F9/2 → 6H13/2 transition. The Judd-Ofelt (J-O) parameters (Ω2, Ω4, Ω6) were computed using the excitation spectra. The characteristics of the Dy3+ transition indicate that the asymmetric environment around the ligand was suggested by the trend, which was followed by J-O parameters. Due to the dominance of the electric-dipole transition in the luminescence spectrum, the Ba2La8(SiO4)6O2:0.03Dy3+ phosphor displayed yellowish white emission with CIE coordinates of (0.358, 0.398) and a CCT of 4724 K. The synthesized phosphor may be a useful material in the fabrication of white-emitting phosphor for LEDs application. 相似文献
9.
《Ceramics International》2016,42(15):16579-16583
Tb3+-Sm3+ co-doped Sr9Gd(PO4)5(SiO4)F2 (SGPSF) phosphors were prepared through a solid-state reaction, and their luminescence properties as well as energy transfer mechanism have been investigated in detail. The SGPSF:Tb3+, Sm3+ phosphors system could be efficiently excited at wavelengths ranging from 200 to 500 nm, which is well matched with the spectra of near ultraviolet chips. The emission of SGPSF:Tb3+, Sm3+ phosphor covers the entire visible region with sharp peaks in the blue, green, and red regions. The emission color of SGPSF:Tb3+, Sm3+ could be adjusted from green (0.275, 0.378) to red (0.519, 0.295) by controlling the doping content of Sm3+/Tb3+. 相似文献
10.
White light emitting dysprosium-doped Ca3Bi(PO4)3 phosphor was successfully synthesized via co-precipitation method for the first time and the structural, vibrational, morphological, and luminescent properties have been investigated for solid-state lighting applications. X-ray diffraction (XRD) and structural refinement studies reveal that the synthesized phosphors consist of single phase with cubic structure. The field emission scanning electron microscopy (FE-SEM) images reveal that the as-synthesized phosphor has micron size particle with an irregular shape. Under near-ultraviolet (n-UV) and blue excitation, the phosphor exhibits white light emission via a combination of blue (~484 nm) and yellow (~575 nm) emission bands. The optimized concentration of Dy3+ ions is 6.0 mol % after which the concentration quenching takes place. The process of energy transfer between Dy3+ ions is due to dipole-dipole interaction, which was confirmed by applying Dexter's theory. The CIE chromaticity coordinates for the optimized phosphor were (0.329, 0.377), and they lie in the white light region. The emission intensity remains to be 83.41% at 373 K to that of at room temperature, which indicates good thermal stability. The above mentioned results demonstrate that Ca3Bi(PO4)3 is a potential phosphor for solid-state lighting applications. 相似文献
11.
《硅酸盐学报》2015,(9)
采用固相法合成Ca9Al(PO4)7:Tb3+,Ce3+绿色荧光粉,研究了材料的发光性质。结果表明,以377 nm近紫外光作为激发源时,Ca9Al(PO4)7:Tb3+呈现出多峰特征,主峰位于491、545、589和623 nm,分别对应Tb3+的5D4→7F6,5D4→7F5,5D4→7F4和5D4→7F3跃迁发射,其中545 nm发射峰最强,从而材料整体发射绿光;监测545 nm发射峰,对应的激发光谱为多峰特征,覆盖300~390 nm;增大Tb3+的掺杂量,发现Ca9Al(PO4)7:Tb3+的发射强度逐渐增大,在实验范围内,并未出现浓度猝灭现象;通过添加A+(A=Li、Na和K)以及敏化剂Ce3+,有效增强了Tb3+在Ca9Al(PO4)7中的发射强度。测量了不同Tb3+掺杂量下材料的色坐标,发现Ca9Al(PO4)7:Tb3+的色坐标基本不变,位于绿色区域。 相似文献
12.
Preparation,luminescence properties and energy transfer of Ca9Y(PO4)7: Eu2+‐Tb3+ phosphors
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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
13.
《Ceramics International》2019,45(14):16963-16968
Cationic substitution is a prevalent strategy to tune the luminescence spectra of phosphors. In this work, we reported a series of Eu2+-activated whitlockite type Ca7Sr3.5-0.5xAx(PO4)7 (CSPA; A =Li, Na, K) (x = 0–1.00) phosphors. The substitution by Na+ for both half occupied/vacant M(4) site was verified via Raman spectra, Reitveld refinement and HR-TEM, whereas a similar accommodation of K+ into the Ca2Sr(PO4)2 (CSP) host cannot be realized due to the significant size mismatch. A continuous increase of Na+ contents led to the progressively structural contraction, promoting the migration of Eu2+ activator from looser M(4) to other sites, and regulating the luminescence behaviors. Consequently, the gradual red-shift of emission band terminated at a new yellow phosphor Ca7Sr3Na(PO4)7:0.04Eu2+. The cation vacancy repair developed in this work can not only migrate the Eu2+ activator among different cation sites, but also serves as a new strategy for tuning the luminescence properties of phosphor. 相似文献
14.
15.
《Ceramics International》2016,42(12):13919-13924
A series of green-to-red color-tunable Sr3La(PO4)3:Tb3+, Eu3+ phosphors were prepared by high temperature solid-state method. The crystal structures, photoluminescence properties, fluorescence lifetimes, and energy transfer of Sr3La(PO4)3:Tb3+, Eu3+ were systematically investigated in detail. The obtained phosphors show both a green emission from Tb3+ and a red emission from Eu3+ with considerable intensity under ultraviolet (UV) excitation (~377 nm). The emission colors of the phosphors can be tuned from green (0.304, 0.589) through yellow (0.401, 0.505) and eventually to red (0.557, 0.392) due to efficient Tb3+-Eu3+ energy transfer (ET). The Tb3+→Eu3+ energy transfer process was demonstrated to be quadrupole-quadrupole mechanism by Inokuti-Hirayama model, with maximum ET efficiency of 86.3%. The results indicate that the Sr3La(PO4)3:Tb3+, Eu3+ phosphors might find potential applications in the field of lighting and displays. 相似文献
16.
《Ceramics International》2016,42(5):6115-6120
Ce3+ and Tb3+ singly doped and co-doped GdAl3(BO3)4 phosphors were synthesized by solid state reaction. The crystal structure, the luminescent properties, the lifetimes and the temperature-dependent luminescence characteristic of the phosphors were investigated. Through an effective energy transfer, the emission spectra of GdAl3(BO3)4:Ce3+, Tb3+ phosphor contains both a broad band in the range of 330–400 nm originated from Ce3+ ions and a series of sharp peaks at 484, 541, 583, and 623 nm due to Tb3+ ions. The energy transfer from Ce3+ to Tb3+ in GdAl3(BO3)4 host is demonstrated to be phonon assisted nonradiative energy transfer via a dipole–dipole interaction. 相似文献
17.
Weilun Zhang Yujun Liang Yingli Zhu Shiqi Liu Haoran Li Wen Lei 《Journal of the American Ceramic Society》2019,102(9):5223-5233
A series of Ce3+ and Tb3+ singly- and co-doped NaBa4(AlB4O9)2Cl3 (NBAC) phosphors have been synthesized via high-temperature solid state route. The crystal structure, morphology, photoluminescent properties, thermal properties and energy transfer process between Ce3+ and Tb3+ were systematically investigated. The structure refinements indicated that the phosphors based on NBAC crystallized in P42nm polar space group in monoclinic phase. The emission color could be tuned from blue (0.1595, 0.0955) to green (0.2689, 0.4334) via changing the ratio of Ce3+/Tb3+. The energy transfer mechanism of Ce3+/Tb3+ was verified to be dipole–quadrupole interaction via the examination of decay times of Ce3+ based on Dexter's theory. The good thermal stability showed the intensities of Ce3+ at 150°C were about 66.9% and 64.88% in NBAC:0.09Ce3+ and NBAC:0.09Ce3+, 0.07Tb3+ of that at room temperature, and the emission intensities of Tb3+ remained 102.41% in NBAC:0.11Tb3+ and 95.22% in NBAC:0.09Ce3+, 0.07Tb3+ due to the nephelauxetic shielding effect and the highly asymmetric rigid framework structure of NBAC. The maximum external quantum efficiency (EQE) of Ce3+ in NBAC:0.09Ce3+, yTb3+ phosphors could reach 43.38% at y = 0.13. Overall, all the results obtained suggested that NBAC:Ce3+, Tb3+ could be a promising option for n-UV pumped phosphors. 相似文献
18.
White‐emitting phosphor Ba2B2O5:Ce3+, Tb3+, Sm3+: Luminescence,energy transfer,and thermal stability
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Shuchao Xu Zhijun Wang Panlai Li Ting Li Qiongyu Bai Jiang Sun Zhiping Yang 《Journal of the American Ceramic Society》2017,100(5):2069-2080
A series of Ba2B2O5: RE (RE=Ce3+/Tb3+/Sm3+) phosphors were synthesized using high‐temperature solid‐state reaction. The X‐ray diffraction (XRD), luminescent properties, and decay lifetimes are utilized to characterize the properties of the phosphors. The obtained phosphors can emit blue, green, and orange‐red light when single‐doped Ce3+, Tb3+, and Sm3+. The energy can transfer from Ce3+ to Tb3+ and Tb3+ to Sm3+ in Ba2B2O5, but not from Ce3+ to Sm3+ in Ce3+ and Sm3+ codoped in Ba2B2O5. However, the energy can transfer from Ce3+ to Sm3+ through the bridge role of Tb3+. We obtain white emission based on energy transfer of Ce3+→Tb3+→Sm3+ ions. These results reveal that Ce3+/Tb3+/Sm3+ can interact with each other in Ba2B2O5, and Ba2B2O5 may be a potential candidate host for white‐light‐emitting phosphors. 相似文献
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20.
Hsin‐Cheng Lin Che‐Yuan Yang Subrata Das Chung‐Hsin Lu 《Journal of the American Ceramic Society》2014,97(6):1866-1872
A series of newly developed color‐tunable Ca3La6(SiO4)6: Ce3+, Tb3+ phosphors were successfully prepared in this study. The crystal structures of the prepared phosphors were revealed to be hexagonal with space group P63/m, and the lattice parameters were evaluated via utilizing the Rietveld refinement method. Upon excitation at 288 nm, the emission spectra of Ce3+and Tb3+ ions co‐doped Ca3La6(SiO4)6 phosphors included a blue emission band and several emission lines. The blue emission band with a peak at 420 nm originated in the f–d transitions of Ce3+ ions, and the emission lines in the range of 450–650 nm were assigned to the 5D4 → 7FJ (J = 6, 5, 4, 3) transitions of Tb3+ ions. Increasing the doping content of Tb3+ ions considerably strengthened Tb3+ emission and reduced Ce3+ emission owing to the energy transfer from Ce3+ to Tb3+ ions. The mechanism of the energy transfer was confirmed to be a dipole–dipole interaction. The effective energy transfer from Ce3+ to Tb3+ ions caused a color shift from purplish‐blue to yellowish‐green. Color‐tunable Ca3La6(SiO4)6: Ce3+, Tb3+ phosphors have the potential to be utilized in light‐emitting diodes with proper modulation of the amount of Tb3+ ions. 相似文献