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1.
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
2.
Synthesis and luminescence properties of CaSnO3:Bi3+ blue phosphor and the emission improvement by Li+ ion
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Renping Cao Jinlong Zhang Wudi Wang Qianglin Hu Wensheng Li Wen Ruan Hui Ao 《Luminescence》2017,32(6):908-912
CaSnO3:Bi3+ blue‐emitting phosphor was synthesized using a high‐temperature solid‐state reaction method in air. The crystal structures and luminescence properties were investigated. A broad emission band peaking at ~448 nm upon excitation at 262 and 308 nm was observed in the range 330–680 nm at room temperature due to 3P1 → 1S0 transition of the Bi3+ ion. The chromaticity coordinate was (0.1786, 0.1665). The optimal Bi3+ ion concentration was ~0.6 mol% in CaSnO3:Bi3+ phosphor. The emission spectrum of CaSnO3:Bi3+ phosphor showed a blue‐shift with increasing temperature from 50 to 300 K due to the influence of temperature on the electron transition of the Bi3+ ion. The emission intensity of CaSnO3:Bi3+ phosphor may be increased ~1.45 times by co‐doping Li+ ions as a charge compensator and fluxing agent. The luminescence mechanism is explained by a configurational coordinate diagram of Bi3+ ion in CaSnO3:Bi3+ phosphor. 相似文献
3.
Xinyue Liu Yamin Xu Kang Cheng Juling Long Weichao Huang Chaoyong Deng 《Luminescence》2023,38(6):692-701
A novel far-red emitting phosphor Sr2MgWO6: Mn4+ was fabricated using high-temperature solid-state reaction. X-ray diffraction patterns, scanning electron microscopy images, and photoluminescence excitation and photoluminescence spectra for this phosphor were analyzed in detail. The analysis revealed that its emission ranged from 600 to 800 nm and peaked at 699 nm, which was attributed to the 2Eg→4A2g transition of Mn4+ under 314 nm excitation. Moreover, we introduced rare-earth Yb3+ ions into the Sr2MgWO6:Mn4+ to improve its far-red emitting intensity. The photoluminescence (PL) intensity of the Yb3+ co-doped phosphor was three times higher than that of the single-doped phosphor. Therefore charge compensation is an efficient approach to improving PL intensity. The phosphor emitted a far-red light that resembled the pigments essential for plant growth in terms of the absorption spectrum. Therefore, the obtained phosphor, Sr2MgWO6:0.006Mn4+,0.2Yb3+, had the potential to be a new type of far-red luminescent powder for indoor plant growth LEDs. 相似文献
4.
Qiongyu Bai Zhijun Wang Panlai Li Ting Li Shuchao Xu Zhiping Yang 《Luminescence》2016,31(6):1277-1282
Ca3Al2Ge2O10:Cr3+ phosphors were prepared by a high‐temperature solid‐state method, and their luminescence properties were investigated. Under excitation at 550 nm, Ca3Al2Ge2O10:Cr3+ phosphors exhibited a broad red emission band at 697 nm in the range 650–750 nm that was caused by the 2E→4A2 transition of Cr3+. For the 697 nm emission peak, emission intensity reached a maximum at x = 0.07, and there was concentration quenching of Cr3+ in Ca3Al2Ge2O10; the corresponding concentration quenching mechanism was analysed. Under excitation at 262 nm, the Ca3Al2Ge2O10:Cr3+ phosphor showed a weakly broad emission band in the range 350–600 nm that was caused by intrinsic defects (V′′Ca and V′′O). Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
5.
T. Kalpana Y. Gandhi V. Sudarsan M. Piasecki V. Ravi Kumar N. Veeraiah 《Luminescence》2016,31(7):1358-1363
BaO‐B2O3‐P2O5 glasses doped with a fixed concentration of Tb3+ ions and varying concentrations of Al2O3 were synthesized, and the influence of the Al3+ ion concentration on the luminescence efficiency of the green emission of Tb3+ ions was investigated. The optical absorption, excitation, luminescence spectra and fluorescence decay curves of these glasses were recorded at ambient temperature. The emission spectra of terbium ions when excited at 393 nm exhibited two main groups of bands, corresponding to 5D3 → 7Fj (blue region) and 5D4 → 7Fj (green region). From these spectra, the radiative parameters, viz., spontaneous emission probability A, total emission probability AT, radiative lifetime τ and fluorescent branching ratio β, of different transitions originating from the 5D4 level of Tb3+ ions were evaluated based on the Judd‐Ofelt theory. A clear increase in the quantum efficiency and luminescence of the green emission of Tb3+ ions corresponding to 5D4 → 7F5 transition is observed with increases in the concentration of Al2O3 up to 3.0 mol%. The improvement in emission is attributed to the de‐clustering of terbium ions by Al3+ ions and also to the possible admixing of wave functions of opposite parities. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
6.
The structural and optical properties of commercially obtained Y3Al5O12:Ce3+ phosphor were investigated by replacing Al3+ with Ga3+ and Y3+ with Gd3+ in the Y3Al5O12:Ce3+ structure to form Y3(Al,Ga)5O12:Ce3+ and (Y,Gd)3Al5O12:Ce3+. X‐Ray diffraction (XRD) results showed slight 2‐theta peak shifts to lower angles when Ga3+ was used and to higher angles when Gd3+ was used, with respect to peaks from Y3Al5O12:Ce3+ and JCPDS card no. 73–1370. This could be attributed to induced crystal‐field effects due to the different ionic sizes of Ga3+ and Gd3+ compared with Al3+ and Y3+. The photoluminescence (PL) spectra showed broad excitation from 350 to 550 nm with a maximum at 472 nm, and broad emission bands from 500 to 650 nm, centred at 578 nm for Y3Al5O12:Ce3+ arising from the 5d → 4f transition of Ce3+. PL revealed a blue shift for Ga3+ substitution and a red shift for Gd3+ substitution. UV–Vis showed two absorption peaks at 357 and 457 nm for Y3Al5O12:Ce3+, with peaks shifting to 432 nm for Ga3+ and 460 nm for Gd3+ substitutions. Changes in the trap levels or in the depth and number of traps due to Ce3+ were analysed using thermoluminescence (TL) spectroscopy. This revealed the existence of shallow and deep traps. It was observed that Ga3+ substitution contributes to the shallowest traps at 74 °C and fewer deep traps at 163 °C, followed by Gd3+ with shallow traps at 87 °C and deep traps at 146 °C. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
7.
Xin‐Yuan Sun Wen‐Feng Wang Shou‐Qiang Sun Liang‐Wu Lin De‐Yi Li Ling‐Ping Zhou 《Luminescence》2013,28(3):384-391
BaGd2‐xO4:xEu3+ and Ba1‐yGd1.79‐2yEu0.21Na3yO4 phosphors were synthesized at 1300°C in air by conventional solid‐state reaction method. Phosphors were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence excitation (PLE) spectra, photoluminescence (PL) spectra and thermoluminescence (TL) spectra. Optimal PL intensity for BaGd2‐xO4:xEu3+ and Ba1‐yGd1.79‐2yEu0.21Na3yO4 phosphors at 276 nm excitation were found to be x = 0.24 and y = 0.125, respectively. The PL intensity of Eu3+ emission could only be enhanced by 1.3 times with incorporation of Na+ into the BaGd2O4 host. Enhanced luminescence was attributed to the flux effect of Na+ ions. However, when BaGd2O4:Eu3+ phosphors were codoped with Na+ ions, the induced defects confirmed by TL spectra impaired the emission intensity of Eu3+ ions. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
8.
Ca3(PO4)2:Eu3+ phosphor preparation with different morphologies and their fluorescence properties
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Ca3(PO4)2:Eu3+ phosphor was prepared using a facile chemistry method in the presence of surfactants. The effects of surfactants on the morphology and photoluminescence properties of Ca3(PO4)2:Eu3+ phosphor were investigated. The morphology of the phosphor was significantly influenced by the surfactants employed. When nonionic surfactant glyceryl monostearate and anionic surfactant sodium dodecylbenzene sulfonate were employed, the phospor powders are composed of a large number of homogeneous spherical particles with sizes of 0.3–0.6 µm and 2–3 µm, respectively. By contrast, when cationic surfactant cetyltrimethylammonium bromide was used, the morphology of the phosphor is completely different. The product is an excellent cuboid, and the phosphor prepared with 2.5 mmol cetyltrimethylammonium bromide showed higher luminescent intensity than phosphors prepared with the other two types of surfactants. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
9.
A blue CaMgSi2O6:Eu2+ phosphor was prepared by the solid‐state reaction method and the phosphor characterized in terms of crystal structure, particle size, photoluminescence (PL), thermoluminescence (TL) and mechanoluminescence (ML) properties using X‐ray diffraction (XRD), transmission electron microscopy (TEM), PL spectroscopy, TLD reader and ML impact technique. The XRD result shows that phosphor is formed in a single phase and has a monoclinic structure with the space group C2/c. Furthermore, the PL excitation spectra of Eu2+‐doped CaMgSi2O6 phosphor showed a strong band peak at 356 nm and the PL emission spectrum has a peak at 450 nm. The depths and frequency factors of trap centers were calculated using the TL glow curve by deconvolution method in which the trap depths were found to be 0.48 and 0.61 eV. The formation of CaMgSi2O6:Eu2+ phosphor was confirmed by Fourier transform infrared spectroscopy. The ML intensity increased linearly with the impact velocity of the piston used to deform the phosphor. It was shown that the local piezoelectricity‐induced electron bombardment model is responsible for the ML emission. Finally, the optical properties of CaMgSi2O6:Eu2+ phosphors are discussed. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
10.
The BaZrSi3O9:Cr3+ phosphors were prepared by a high temperature solid state method. Their structures were confirmed with XRD and their luminescence properties were investigated. Under excitation at 455 nm, BaZrSi3O9:Cr3+ phosphors exhibited a broad near infrared emission band peaked at 800 nm, which was assigned to the 4T2→4A2 transition of Cr3+. The near infrared emission intensity reached a maximum at Cr3+ concentration of 0.7%. There was a concentration quenching phenomenon of Cr3+ in BaZrSi3O9 matrix and the corresponding concentration quenching mechanism was investigated. With efficient near infrared emission in the range of 700–1000 nm, BaZrSi3O9:Cr3+ phosphors may find applications in solar energy conversion. 相似文献
11.
Concentration dependence of luminescence efficiency of Dy3+ ions in strontium zinc phosphate glasses mixed with Pb3O4
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In this work we synthesized SrO–ZnO–P2O5 glasses mixed with Pb3O4 (heavy metal oxide) and doped with different amounts of Dy2O3 (0.1 to 1.0 mol%). Subsequently their emission and decay characteristics were investigated as a function of Dy2O3 concentration. The emission spectra exhibited three principal emission bands in the visible region corresponding to 4F9/2 → 6H15/2 (482 nm), 6H13/2 (574 nm) and 6H11/2 (663 nm) transitions. With increase in the concentration of Dy2O3 (upto 0.8 mol%) a considerable increase in the intensity of these bands was observed and, for further increase, quenching of photoluminescence (PL) output was observed. Using emission spectra, various radiative parameters were evaluated and all these parameters were found to increase with increase in Dy2O3 concentration. The Y/B integral emission intensity ratio of Dy3+ ions evaluated from these spectra exhibited a decreasing trend with increase in the Dy2O3 concentration up to 0.8 mol%. Quenching of luminescence observed in the case of the glasses doped with 1.0 mol% is attributed to clustering of Dy3+ ions. The quantitative analysis of these results together with infra‐red (IR) spectral studies indicated that 0.8 mol% is the optimum concentration of Dy3+ ions needed to achieve maximum luminescence efficiency. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
12.
An orange‐emitting phosphor, Eu2+‐activated LiSr4(BO3)3, was synthesized using the conventional solid‐state reaction. The photoluminescence excitation and emission spectra, and temperature dependence of the luminescence intensity of the phosphor were investigated. The results showed that LiSr4(BO3)3:Eu2+ could be efficiently excited by incident light of 250–450 nm, and emits a strong orange light. With increasing temperature, the emission bands of LiSr4(BO3)3:Eu2+ show an abnormal blue‐shift with broadening bandwidth and decreasing emission intensity. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
13.
Enhanced photoluminescence of the Ca0.8Zn0.2TiO3:0.05% Pr3+ phosphor by optimized hydrothermal conditions
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Mao Xia Guanhua Wang Zhiqiang Gu Zhongxian Qiu Chunying Rong Jilin Zhang Wenli Zhou Liping Yu Shixun Lian 《Luminescence》2017,32(6):999-1008
The red‐emitting phosphor Ca0.8Zn0.2TiO3:Pr3+ was synthesized using an ethylene glycol (EG)‐assisted hydrothermal method. The effects of additional amounts of and order of adding EG, plus hydrothermal temperature, time, and pH on the composition, morphology and optical properties of the titanate phosphors were studied. The crystalline phases of the titanate phosphors were confirmed to be constituted of a series of co‐existing CaTiO3, Zn2TiO4 and Ca2Zn4Ti16O38 compounds in various proportions that were visualized using an X‐ray diffractometer (XRD). The optical properties of the phosphors were studied using photoluminescence spectra and UV–visible spectroscopy. The results show that the impurities Zn2TiO4:Pr3+ and Ca2Zn4Ti16O38:Pr3+ significantly contributed to the enhancement of an absorption band around 380 nm. The optimum Ca0.8Zn0.2TiO3:Pr3+ phosphor consisting of appropriate amounts of CaTiO3, Ca2Zn4Ti16O38 and Zn2TiO4 in three phases was achieved by controlling the hydrothermal conditions, and the obtained red phosphor exhibited the highest red emission (1D2 → 3H4 transition of Pr3+) with an ideal chromaticity coordinate located at (x = 0.667, y = 0.332) under 380 nm excitation. 相似文献
14.
A novel blue‐emitting phosphor of Eu2+‐activated NaMgPO4 was prepared by combustion‐assisted synthesis. Sodium dihydrogen phosphate and magnesium nitrate were used as the source of Na, P and Mg, respectively. The ratios of magnesium and phosphorus components that were dissolved into the combustion solution were changed from 1:1 to 1:1.3. Their effect on the crystallinities and photoluminescence spectra of the phosphor particles were investigated. The post‐heated phosphor particles had a broad excitation wavelength that ranged from 240 to 410 nm. The phosphor particles prepared from the combustion solution with a 1:1.2 ratio of magnesium to phosphorus had maximum emission intensity under ultraviolet excitation. The effect of doped Eu2+ concentration on the emission intensity of NaMgPO4:Eu2+ was also investigated. 相似文献
15.
Swift heavy ion induced structural and luminescence characterization of Y2O3:Eu3+ phosphor: a comparative study
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We report a comparative study on structural and thermoluminescence modifications of Y2O3:Eu3+ phosphor induced by 150 MeV Ni7+, 120 MeV Ag9+ and 110 MeV Au8+ swift heavy ions (SHI) in the fluence range 1 × 1011 to 1 × 1013 ions/cm2. X‐Ray diffraction and transition electron microscopy studies confirm the loss of crystallinity of the phosphors after ion irradiation, which is greater in the case of Au ion irradiation. Structural refinement using the Rietveld method yields the various structural parameters of ion‐irradiated phosphors. Thermoluminescence glow curves of ion‐irradiated phosphors show a small shift in the position of the peaks, along with an increase in intensity with ion fluence. Stopping range of ions in Matter (SRIM) calculations were performed to correlate the change in thermoluminescence properties of various ion‐irradiated phosphors. It shows that the defects created by 110 MeV Au8+ ions are greater in number. Trapping parameters of ion‐irradiated phosphors were calculated from thermoluminescence data using various glow curve analysis methods. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
16.
Crystal structure and luminescence properties of the blue‐green‐emitting Ba9(Lu,Y)2Si6O24:Ce3+ phosphor
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Huawei Xu Zhi Zhou Yongfu Liu Qunxing Liu Zhiyuan He Shen Wang Linyi Huang Hongbo Zhu 《Luminescence》2017,32(5):812-816
Samples of the Ba9(Lu2‐xYx)Si6O24:Ce3+ (x = 0–2) blue‐green phosphors were synthesized by solid‐state reactions. All the samples exhibited a rhombohedral crystal structure. As the Y3+ concentration increased, the diffraction peaks shifted to the small angle region and the lattice parameters increased due to the larger ionic radius of Y3+ (r = 0.900 Å) compared with that of Lu3+ (r = 0.861 Å). Under 400 nm excitation, samples exhibited strong blue‐green emissions around 490 nm. The emission bands had a slight blue shift that resulted from weak crystal‐field splitting with increasing Y3+ concentration. Luminescence intensity and quantum efficiency (QE) decreased with increasing Y3+ concentration. The internal QE decreased from 74 to 50% and the external QE decreased from 50 to 34% as x increased from 0 to 2. The thermal stability of the Lu series was better than that of the Y‐series. The excitation band peak around 400 nm matched well with the emission light from the efficient near‐ultraviolet (NUV) chip. These results indicate promising applications for these NUV‐based white light‐emitting diodes. 相似文献
17.
The new borate phosphor CaB2O4:Eu3+ was synthesized by solid‐state method and their photoluminescence properties were investigated. The results show that the pure phase of CaB2O4 could be available at 900°C, CaB2O4:Eu3+ phosphor could be effectively excited by the near ultraviolet light (NUV) (392 nm), and the luminescent intensity of CaB2O4:Eu3+ phosphor reached to the highest when the doped‐Eu3+ content was 4 mol%. The emission spectra of CaB2O4:Eu3+ phosphor could exhibit red emission at 612 nm and orange emission at 588 nm, which are ascribed to the 5D0–7F2 and 5D0–7F1 transitions of Eu3+ ions. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
18.
Luminescence properties of Tm3+ ions single‐doped YF3 materials in an unconventional excitation region
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According to the spectral distribution of solar radiation at the earth's surface, under the excitation region of 1150 to 1350 nm, the up‐conversion luminescence of Tm3+ ions was investigated. The emission bands were matched well with the spectral response region of silicon solar cells, achieved by Tm3+ ions single‐doped yttrium fluoride (YF3) phosphor, which was different from the conventional Tm3+/Yb3+ ion couple co‐doped materials. Additionally, the similar emission bands of Tm3+ ions were achieved under excitation in the ultraviolet region. It is expected that via up‐conversion and down‐conversion routes, Tm3+‐sensitized materials could convert photons to the desired wavelengths in order to reduce the energy loss of silicon solar cells, thereby enhancing the photovoltaic efficiency. 相似文献
19.
Dinesh S. Bobade Yatish R. Parauha Sanjay J. Dhoble Prabhakar B. Undre 《Luminescence》2022,37(3):500-513
The present communication is strongly focused on the investigation of synthesis, structural and luminescence properties of cerium (Ce3+)- and europium (Eu3+)-activated Zn4Al22O37 phosphors. Ce3+- and Eu3+-doped Zn4Al22O37 novel phosphors were prepared using a solution combustion synthesis route. Structural properties were studied using powder X-ray diffraction and high-resolution transverse electron microscopy. The optical properties were studied using ultraviolet–visible light spectroscopy and Fourier transform infrared spectroscopy; luminescence properties were studied using a photoluminescence (PL) technique. The crystal structure of the prepared Zn4Al22O37 host and Ce3+- and Eu3+-activated Zn4Al22O37 phosphors was investigated and was found to have a hexagonal structure. The measured PL emission spectrum of the Ce3+-doped Zn4Al22O37 phosphor showed an intense and broad emission band centred at 421 nm under a 298 nm excitation wavelength. By contrast, the Eu3+-doped Zn4Al22O37 phosphor exhibited two strong and intense emission bands at approximately 594 nm (orange) and 614 nm (red), which were monitored under 395 nm excitation. The Commission Internationale de l’Eclairage (CIE) colour coordinates of the Ce3+-doped Zn4Al22O37 were investigated and found to be x = 0.1567, y = 0.0637 (blue) at 421 nm and for Eu3+-doped Zn4Al22O37 were x = 0.6018, y = 0.3976 (orange) at 594 nm and x = 0.6779, y = 0.3219 (red) at 614 nm emission. The luminescence behaviour of the synthesized phosphors suggested that these phosphors may be used in lighting applications. 相似文献
20.
Effect of sintering temperature on the luminescence properties of Ca0.8Ba0.2TiO3:Pr3+ red‐emitting phosphor
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Yannan Mu Min Qiu Xiaoming Zhou Qian Li Meiling Sun Haibin Yang Wuyou Fu Lihua Yang Jinwen Ma 《Luminescence》2015,30(5):503-506
Nanoparticles with the nominal composition Ca0.8Ba0.2Ti03:Pr3+ were prepared using the sol–gel process. Barium nitrate, 4‐hydrated calcium nitrate and praseodymium oxide were used as raw materials. The structural evolution and decomposition processes of the precursors were investigated by powder X‐ray diffraction, differential thermal analysis and thermogravimetric analysis. Crystalline Ca0.8Ba0.2Ti03:Pr3+ could be obtained at 700°C. The photoluminescence properties of the samples were investigated using excitation and emission spectra. Ca0.8Ba0.2Ti03:Pr3+ nanoparticles showed strong red emission, which could be assigned to the typical 1D2→3H4 transition of Pr3+. Furthermore, the study found that sintering temperature and the introduction of Ba2+ influence the decay time of persistent luminescence. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献