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1.
In order to effectively improve the afterglow properties of CaAl_2 O_4:Eu~(2+),Nd~(3+) phosphors,a series of Ca_(0.982-x)Al_2 O_4:0.012 Eu~(2+),0.006 Nd~(3+),xGd~(3+)(x=0,0.012,0.024,0.036,0.048,0.060 mol) phosphors were prepared by a high-temperature solid-phase approach.Crystalline composition and microstructure were characterized by XRD,TEM,HRTEM,and XPS,luminescence properties were systematically analyzed by fluorescence spectra,afterglow decay curves and TL glow curve.Results show that all of Ca_(0.982-x)Al_2 O_4:0.012 Eu~(2+),0.006 Nd~(3+),xGd~(3+)phosphors belong to monoclinic CaAl_2 O_4,without other cystalline phase.The blue emission at 442 nm is observed,which is assigned to the 4 f~65 d→4 f~7 transition of Eu~(2+) ions.Doping with appropriate amount of Gd~(3+) ions(x=0.036 mol) significantly improves the afterglow properties of phosphors,but the excessive doping of Gd~(3+) induces the fluorescent quenching.The doping of moderate Gd3+changes the traps states,the trap depth varies from 0.598 to 0.644 eV and the trap concentration is also greatly improved,thus significantly improving afterglow performance. 相似文献
2.
Junzhi Che Bin Deng Qinyang Song Jianxu Wang Tao Wang Shoucheng Zhao Ruijin Yu 《中国稀土学报(英文版)》2021,39(6):634-642
Novel yellow-emitting phosphors of Dy~(3+)-doped double perovskite Ca_2 MgTeO_6 were synthesized by using a conventional high-temperature solid-state reaction.The phase purity,particle morphology,size distribution,elemental composition,luminescence properties,and luminescence decay curves of the resulting products were then analyzed in detail.The Ca2 MgTeO_6:Dy~(3+),Na~+ phosphors show three emission peaks after near-ultraviolet excitation at 350 nm,which correspond to ~4 F_(9/2)→~6 H_(11/2),~4 F_(9/2)→~6 H_(13/2),and ~4 F_(9/2)→~6 H_(13/2) transitions,respectively.Among them,the strongest peak is observed at 573 nm.The best doping content of Dy~(3+)in Ca_2 MgTeO_6:xDy~(3+),xNa~+ phosphors is x=5 mol%.The calculated critical distance of energy transfer between Dy~(3+) ions is 1.6 nm.Luminescence quenching is confirmed to be due to dipole-dipole interactions among Dy~(3+) ions.The phosphors show excellent thermal stability with high activation energy(0.27 eV).The Commission Internationale de l'Eclairage(CIE) chromaticity coordinates of the Ca_2 MgTeO_6 Dy~(3+),Na~+ phosphors are located in the yellow region.White light-emitting diodes(w-LEDs) were fabricated with a high color rendering index(R_a) of 88 and a good correlated color temperature(CCT) of 5440 K.All observed properties indicate that Ca_2 MgTeO_6:Dy~(3+),Na~+ phosphors have potential applications in display and photonic devices. 相似文献
3.
Lin Luo Ronghui Liu Yuanhong Liu Weidong Zhuang Yanfeng Li Shaowei Qin 《中国稀土学报(英文版)》2021,39(4):380-385
A series of non-rare earth Mn4+-activated strontium aluminate phosphors Sr4Al14O25:Mn4+co-doped with Sc3+ions were successfully synthesized by a high-temperature solid-state reaction method.XRD result reveals that there is no introduction of additional phase but expansion of lattice with incorporation of Sc34 ions.Excitation and emission spectrum measurement shows that the synthesized phosphors can be efficiently excited by near-ultraviolet and blue light,and a deep red emission centered at 652 nm with a narrow full width at half maximum(FWHM)can be obtained,which is attributed to the transition2E→4A2of Mn4+ions.In addition,the crystal field strength parameter(Dq)and Racah parameters(B,C)and energies of states were calculated based on experimental data.Moreover,the luminous intensity of Sr4Al14-xSCxO25:Mn4+is enhanced and increased by 60%compared with Mn4+single incorporated sample at x=0.06.A phenomenon of redshift is observed in the excitation spectrum and discussed systematically.Finally,the mechanism of the positive effects with Sc3+ions incorporated into lattice is discussed in detail.All the results suggest that the Sr4Al13.94Sc0.06O25:Mn4+phosphor will become one of the great candidates for backlight of LCD. 相似文献
4.
Sr3-z(Alx,Si1-x)O -5-xFx:zCe3+ phosphors were synthesized by high-temperature solid-state reaction.The structure and luminescence properties of phosphors with various Al/Si ratios and Ce3+ concentrations were characterized using various methods such as X-ray diffraction,photoluminescence excitation and photoluminescence spectra.XRD result displayed that a complete solid solution between Sr3AlO4F and Sr3SiO5 was formed.With the increasing of x value,a broader excitation band and stronger absorption appeared in the blue light region.Moreover,the emission band shifted to a shorter wavelength and the emission intensity reached a maximum at x=0.6.By adjusting the concentration of Ce3+,a widely tunable range of emission wavelength under the excitation of 460 nm was obtained from the green to yellow regions.In addition,the concentration and thermal quenching were also discussed. 相似文献
5.
《中国稀土学报(英文版)》2022,40(12):1827-1836
In this study, novel yellow-emitting fluorophosphate NaCa3Bi(PO4)3F phosphors doped with different concentrations of Dy3+ ions were first obtained via high-temperature solid-state reaction. The crystal structure, phase purity, particle morphology, photoluminescence (PL) properties, thermal stability, and luminescence decay curves of the resulting phosphors were then characterized in detail. Under the excitation of 349 nm, the three dominant peaks of the NaCa3Bi(PO4)3F:Dy3+ are centered at 480 nm (4F9/2-6H15/2), 577 nm (4F9/2-6H13/2), and 662 nm (4F9/2-6H11/2). The optimal doping concentration of Dy3+ ions in the NaCa3Bi(PO4)3F:xDy3+ phosphors is x = 5 mol%. The phosphors show excellent thermal stability with high activation energy (Ea = 0.32 eV). Eventually, the synthesized white light-emitting diode (w-LED) demonstrates the Commission International de L'Eclairage (CIE) chromaticity coordinates of (0.341, 0.334), a good correlated color temperature (CCT) of 5083 K, and a high color rendering index (Ra) of 92. Revealing its potential as yellow-emitting phosphors, the feasibility of the fabricated apatite-type NaCa3Bi(PO4)3F:Dy3+ fluorophosphate phosphors was confirmed for w-LEDs. 相似文献
6.
Yaru Yang Yiting Lin Yue Han Zhongxian Qiu Wenli Zhou Jilin Zhang Chengzhi Li Liping Yu Shixun Lian 《中国稀土学报(英文版)》2018,36(11):1150-1156
The designed Ce~(3+)-doped alkaline-earth silicate phosphors Ca_mSr_(2-m-n)Ba_nSiO_4:Ce~(3+),Li~+(CSBS:Ce~(3+))were synthesized by a high temperature solid-state reaction. The crystal field splitting and the centroid shift from the free ion energy of 5 d configuration were approximated from the spectrum for Ca_2SiO_4,Sr_2SiO_4 and Ba_2SiO_4 phosphors. The single-phase purity was checked by means of X-ray diffraction. Here,when the doped concentration of Ca~(2+) is less than 80%(m ≤1.6), we report the structural phase transformation from monoclinic system β-Ca_2SiO_4 to orthorhombic system α-Ca_2SiO_4. The phosphors excited by near-ultraviolet(NUV) light at wavelengths ranging from 200 to 400 nm demonstrate a broad asymmetric blue emission band. The emission peak wavelength redshifts firstly from 417 nm of Ca_2SiO_4 to 438 nm of Sr_(0.3)Ca_(1.6)SiO_4, and then blueshifts to 411 nm of Sr_2SiO_4, and the end of 401 nm of Ba_2SiO_4.These results indicate that the tunable blue-emission of the phosphors can be realized through changing the solid solution components, which has a potential use as a blue component for fabricated precision modulation LEDs light sources and auxiliaries of SSC plastics films for different plant growths.We discuss in detail the possible mechanism and energy diagram of the tunable blue luminescence in Ca_mSr_(2-m-n)Ba_nSiO_4:Ce~(3+),Li~+ phosphors. 相似文献
7.
Tri-doped Ca_9 LiY_(2/3)(PO_4)_7:Ce~(3+),Tb~(3+),Mn~(2+)phosphors were prepared by a high-temperature solid state method.Under UV light excitation,Ca_9 LiY_(2/3)(PO_4)_7:Ce~(3+)samples exhibit a broad band ranging from 320 to 500 nm.At 77 K,the emission spectra of Ca_9 LiY_(2/3)(PO_4)7:Ce~(3+)samples present two obvious emission peaks,indicating that Ce~(3+)ions occupy two different kinds of lattice sites(Ca(1/2) and Ca(3)),As a good sensitizer for Tb~(3+),Ce~(3+)ions in Ca_9 LiY_(2/3)(PO_4)_7 lattice can effectively transfer part of energy to Tb~(3+),and the energy trans fer mechanism is determined to be dipole-dipole interaction.Consequently,the emitting color for Ce~(3+) and Tb~(3+) co-doped Ca_9 LiY_(2/3)(PO_4)_7 samples can be tuned from bluish violet to green.In order to further enlarge the emission gamut,Mn~(2+)ions as red emission components were added,forming tri-doped single-phase Ca_9 LiY_(2/3)(PO_4)_7:Ce~(3+),Tb~(3+),Mn~(2+)phosphors.The Ca_9 LiY_(2/3)(PO_4)_7:Ce~(3+),Tb~(3+),Mn~(2+)phosphors exhibit tunable emission properties through controlling the relative doping concentration of Ce~(3+),Tb~(3+)and Mn~(2+).Especially,Ca_9 LiY_(2/3)(PO_4)_7:0.09 Ce~(3+),0.12 Tb~(3+),0.30 Mn~(2+)can emit warm white light.The sample shows good thermal stability.At 150℃,the emission intensity for Ce~(3+)(360 nm),Tb~(3+)(545 nm) and Mn~(2+)(655 nm) decreases to 63%,69%,and 72% of its initial intensity,respectively.Moreover,the sample obtains good stability after 10 cycles between room temperature and150℃. 相似文献
8.
In the present computational study,we found that Er:Lu2O3materials have promise for application in laser applications.The crystal structure and the electronic and optical properties of Er:Lu2O3materials were studied using first-principle calculations under the framework of density functional theory.Based on the experimental and calculated results,the structure of Lu2O3was established.The calculated results show that doping by Er3+can effectively improve its absorption coefficient in the ultraviolet region and improve the static dielectric constant of Lu2O3.As the doping concentration of Er3+increases,the energy of the valence band electrons excited to the conduction band decreases,and the transition is more likely to occur.The absorption coefficient,reflectance,and electron energy loss spectroscopy are bathochromic shifted.The Lu2-xErxO3(02O3. 相似文献
9.
Ka Ding Siru A Shuo Pang Leyan Shan Yaqi Zhang Pengfei Sun Bin Deng Ruijin Yu 《中国稀土学报(英文版)》2021,39(7):749-756
A novel red-emitting phosphor tantalate Ca_2 YTaO_6:Eu~(3+)was synthesized by a solid-state reaction.The purity and surface morphology of the phosphors were characterized.The Ca_2 YTaO_6:Eu~(3+)phosphors show a sharp emission peak at 612 nm under near-ultraviolet(n-UV) at 395 nm because of the ~5 D_0→~7 F_2 transition of Eu3+.The optimal Eu3+doping concentration in Ca2 YTaO_6 is 40 mol% and the critical energy-transfer distance of Eu3+ions was calculated to be 0.9 nm.The emission spectra of Ca_2 YTaO_6:Eu3+from 300 to 480 K were investigated.The thermal-quenching temperature(T_(0.5)) of Ca_2 YTaO_6:Eu~(3+)is above 480 K.The color purity of Ca_2 YTaO_6:40 mol%Eu3+is as high as 99.8%.The luminescence lifetime of Ca_2 YTaO_6:40 mol%Eu~(3+)was also discussed.The high color purity and high thermal stability of Eu~(3+)-doped Ca2 YTaO6 phosphors contribute to its application value in white lightemitting diodes(w-LEDs). 相似文献
10.
《中国稀土学报(英文版)》2022,40(4):526-533
With narrow red photoluminescence (PL) bands, tetravalent Mn4+ doped phosphors show promising prospect in commercial application to effectively expand color gamut of phosphor converted LED displays. Here, we report a type of Sr2–zMg1+yYzAl22–xO36:xMn4+ phosphors with regular cage-like micro-spherical morphologies. The micron size spherical precursors were synthesized with a propylene oxide (PO) driven fast sol–gel method. The cage -like spherical morphology is beneficial to efficiently trapping much incident light to enhance the PL of the phosphors. Being calcined at 1300 °C, Sr2MgAl21.978O36:0.022Mn4+ only exhibits the internal quantum efficiency (IQE) of 24.91%. With the Mg2+-Mn4+ codoping and Y3+/Sr2+ substituting strategies, to fulfill charge balance and produce John-Teller distortion, IQE of Sr2–zMg1+yYzAl22–xO36:xMn4+ can be further improved up to 36.45%. The CIE color coordinates of Sr2–zMg1+yYzAl22–xO36:xMn4+ under near ultraviolet excitation can be stably fixed to (0.723, 0.227) at deep red region. It thus finds a potential application as pc-LED display with much broader color gamut than that of the NTSC standard. Therefore, Sr2–zMg1+yYzAl22–xO36:xMn4+ micron size spheres can be employed as promising red phosphors for high performance LED displays. 相似文献
11.
《中国稀土学报(英文版)》2020,38(2):113-123
In this paper,luminescence thermal quenching of M_2SiO_4:Eu~(2+)(M=Sr,Ba) orthosilicate phosphors and mechanisms for thermal quenching proposed by different authors are briefly reviewed.Depending on preparation conditions and/or Eu~(2+)-doping concentrations,the quenching temperature(T_(1/2)) and activation energy for thermal quenching of the same orthosilicate phosphor reported by different authors are inconsistent.The common conclusion is that T_(1/2) of the intermediate compound(Ba_(1-x)Sr_x)_2 SiO_4:Eu~(2+)(x≈0.5) is higher than that of either Sr_2So_4;Eu~(2+)or Ba_2SiO_4;Eu~(2+)end-member.Moreover,T_(1/2) of the best-performing SrBaSiO_4:Eu~(2+)is evidently lower than that of YAG:Ce~(3+)and some Eu~(2+)-doped nitride phosphors.Rega rding the quenching mechanism,most of the investigators attributed thermal quenching to a thermally assisted 4f-5d cross-over in the configuration coordinate diagram.Only a few authors ascribed thermal quenching to a thermally assisted photoionization of 5 d electron to conduction band of the host.Nonetheless,a close inspection of T_(1/2) and Stokes shift derived from the vibrational spectra of the intermediate compound and end-member phosphors indicates that the 5d electron photo ionization model instead of the 4f-5d crossing decay model should be the genuine mechanism for the thermal quenching of M_2 SiO_4:Eu~(2+)(M=Sr,Ba) phosphors.Since the relationship between T_(1/2) and Stokes shift of the phosphors does not support the 4 f-5 d crossing decay model.The ionization probability of the 5 d electron depends on the energy gap(E_(dC)) between 5 d_1 level of the Eu~(2+)and conduction band minimum(CBM) of the host at higher temperatures.Lattice thermal expansion would result in an elevating 5 d_1 level of the Eu~(2+)along with a diminishing CBM of the host and as a consequence a reduction in E_(dC) and an enhanced photo ionization probability at elevated temperatures.A less rigid lattice and hence a larger coefficient of thermal expansion of M_2SiO_4 hosts should be the physical origin of poorer thermal quenching properties of the orthosilicate phosphors. 相似文献
12.
Haiyan Wu Huimin Li Lihong Jiang Ran Pang Su Zhang Da Li Guanyu Liu Chengyu Li Jing Feng Hongjie Zhang 《中国稀土学报(英文版)》2021,39(3):277-283
The powder samples of Ca9Sc(PO4)7:xDy^(3+)white emitting phosphors were prepared via a solid state reaction technique.The Ca9Sc(PO4)7:Dy3+samples were researched by using the GSAS Rietveld refinement and X-ray diffraction(XRD) methods,and SEM images and elemental maps were recorded.Under 350 nm excitatio n,the emission spectra of Ca9Sc(PO4)7:xDy3+samples have two obvious peaks and one weak peak at 484,572 and660 nm,corresponding to the characteristic electron transitions of(4F9/2→ 6H15/2,blue),(4F9/2→ 6H13/2,yellow) and(4F9/2→ 6 H11/2,red),respectively.The concentration quenching effect,decay lifetime and thermal quenching of the as-synthesized Ca9Sc(PO4)7:Dy3+samples were researched systematically.The Ca9Sc(PO4)7:0.02 Dy3+phosphor possesses a good thermal stability,of which the emission intensity at 423 K can maintain 79% of the initial value(273 K).In addition,through the study of the chro maticity coordinates of the Ca9Sc(PO4)7:0.02 Dy3+phosphor,it is found that it is located in the white region,and the Commission Internationalede L’Eclairage(CIE) chromaticity coordinates are(0.339,0.389),The above results show that Ca9Sc(PO4)7:xDy3+phosphors can be excellent candidate material for applications in NUV-excited white LEDs. 相似文献
13.
Ba0.9-ySryAl12O19:Eu0.1 phosphors were prepared by sol-gel technique, the crystalline structures of samples characterized by XRD, and the luminescence properties were investigated. The influence of crystallographic positions on the luminescent properties of Sr2+-doped BaAl12O19:Eu was investigated in detail. The results indicated that the crystal lattice of BaAl12O19:Eu was not influenced by the Sr2+ and doping Sr2+ in BaAl12O19:Eu enhanced the luminescent properties of the phosphors at the proper concentration of Sr2+. With the increasing of concentration of Sr2+ doped in BaAl12O19:Eu, the relative luminescent intensity of Ba0.9-ySryAl12O19:Eu0.1 strengthened and blue-shifted. 相似文献
14.
《中国稀土学报(英文版)》2020,38(1):1-12
Wide color gamut(WCG) backlight for liquid crystal display(LCD) utilizing white light-emitting diodes(LED) has attracted considerable attention for their high efficiency and color reduction.In this review,recent developments in crystal structure,luminescence and applications of phosphors for wide color gamut LED backlight are introduced.As novel red phosphors,Mn~(4+)activate fluoride and aluminate phosphors are advanced in quantum efficiency,thermal quenching and color saturation for their characteristic spectrum with broad excitation band and linear emission.The crystal structure and fluorescence properties of Mn~(4+)doped fluosilicate,fluorogermanate,fluotitanate,as well as Sr_4 Al_(14)O_(25),CaAl_(12)O_(19) and BaMgAl_(10)O_(17) phosphors are discussed in detail.A serial of narrow-band red-emitting Eu~(2+),Eu~(3+)and Pr~(3+)-doped nitride silicates and molybdate phosphors are also introduced.Rare-earth-doped oxynitride and silicate green-emitting phosphors have attracted more and more attention because of the wide excitation,narrow emission,high quenching temperature,high quantum efficiency,such as β-sialon:Eu~(2+),Ba_3Si_6O_(12)N_2:Eu~(2+),MSi_2O_2N_2:Eu~(2+)(M=Ca,Sr,Ba),y-AlON:Mn~(2+)and Ca_3Sc_2Si_3O_(12):Ce~(3+).All above phosphors demonstrate their adaptability in wide color gamut LCD display.Especially for Mn~(4+)doped fluosilicate red phosphor and β-sialon:Eu~(2+)green phosphor.To achieve an ultra-high color gamut in white LED backlight and against the OLED,innovative narrow-band-emission red and green phosphor materials with independent intellectual property rights are continuously pursed. 相似文献
15.
The Bi3+ doped molybdate-based red-emitting phosphors, LiEu1-xBix(MoO4)2, were successfully synthesized with a sol-gel method. The prepared LiEu1-xBix(MoO4)2 phosphors exhibited pure and intense red emission at 613 nm under the excitation of near-UV 394 nm. It was discussed in detail that the influence of the synthesis conditions such as the doping concentration of Bi3+, the dose of citric acid, pH of the precursor solution and the sintering temperature on the emission intensity of the phosphors. According to the results, the optimal condition was obtained: the doping concentration of Bi3+ was 15 mol.%, molar ratio of citric acid to metal ions was 1.5:1, pH of the precursor solution was 1.0 and the sintering temperature was 800 ?C. The X-ray diffraction (XRD) patterns of the LiEu0.85Bi0.15(MoO4)2 phosphor prepared under the optimal condition indicated that the phosphor was single phase with tetragonal scheelite structure. The Commission Internationale de l’E-clairage (CIE) chromaticity coordinates of LiEu0.85Bi0.15(MoO4)2 were (x=0.655, y=0.345), which were closer to the national television stan-dard committee (NTSC) standard values (x=0.670, y=0.330) than that of a commercial red phosphor of Y2O2S:Eu3+(x=0.630, y=0.350). This LiEu0.85Bi0.15(MoO4)2 red phosphor is a promising candidate for the fabrication of white light-emitting diode (W-LED) with near-UV chips. 相似文献
16.
Eu2+ and (or) Eu3+ doped Sr2SiO4 phosphors particles were synthesized by a conventional solid-state reaction technique, and their structural and optical properties were investigated. The X-ray diffraction (XRD) results showed that the obtained phosphors were composed of orthorhombic α'-Sr2SiO4 and monoclinic β-Sr2SiO4 phase. When excited under 256 nm, Sr2SiO4:Eu3+ phosphors showed intense emission in the red region. Sr2SiO4:Eu3+ phosphors exhibited white emissions (x=0.30, y=0.40, TC=6500 K) ranging from 425 to 650 nm when it was excited by near-ultraviolet (near-UV) light, indicating that Sr2SiO4:Eu2+ was a good light-conversion phosphor candidate for near-UV chip. 相似文献
17.
《中国稀土学报(英文版)》2020,38(3):227-233
Blue-violet light can not only enhance the total content of biomass and glucoside but also enrich the taste of the fruit. Thus, it is meaningful to study the blue-violet luminescent materials for plant cultivation. In this study, titanium (IV) -activated CaYAlO4 (CYAO) phosphors were synthesized by conventional high-temperature solid–state reaction. X-ray powder diffraction was employed to analyze the crystal-structure of CYAO. It is found that the doped Ti4+ ions do not change obviously the crystal structure of phosphors. Upon 246 nm excitation, CaYAl1-xO4:xTi4+ phosphors exhibit broad blue-violet emission band peaking at 395 nm, which can be attributed to the charge transfer of Ti4+–O2–. Moreover, this phosphor exhibits strong thermal stability. The luminescence emission intensity at 150 °C maintained about 91 mol% of its initial value at room temperature. Additionally, the electron transition process and concentration quenching mechanism of CaYAl1–xO4:xTi4+ are discussed in detail. The excellent luminescent properties indicate that CaYAl1-xO4:xTi4+ phosphor may have promising application in indoor plant cultivation. 相似文献
18.
Guantong CHEN Weidong ZHUANG Ronghui LIU Yuanhong LIU Yunsheng HU Huaqiang HE 《中国稀土学报(英文版)》2013,31(10):944-949
Green emitting Eu2+-doped (Ba3_xSrx)Si6012N2 solid solutions were synthesized through solid state reaction at 1350 ℃ for 10 h under a N2/H2 atmosphere. The XRD patterns revealed that the solid solution series of (Ba3 x-ySrx)Si6Ol2N2:yEu2+ with x value ranging from 0-0.6 were established. An efficient and intense tunable green light was observed by varying the cation Sr/Ba ratio. The emission spectra exhibited an entire shift towards long wavelength with increasing ofx value, which was caused by large crystal field splitting and Stokes shift. The x value dependence of emission intensity was discovered and explained by the enhanced probability of electron from excited 4f state to 5d ground state via nonradioactive transition. Highly thermal stability and feasible color coordinates were verified. White LEDs with excellent photochromic properties were fabricated by packing GaN based blue chips and (Ba Sr)3Si6012N2:Eu2+ phosphors. All results indicated that the (Ba3_xSrx)SirO12N2:Eu2+ phosphors were confirmed to be a promising candidate for pc-white LEDs in solid state lighting. 相似文献
19.
Qing Lin Tongyu Gao Yuanhong Liu Ronghui Liu Siwei Chen Xiaole Ma Chunlei Zhao 《中国稀土学报(英文版)》2023,41(8):1127-1134
Red phosphor,with longer wavelength,is highly desirable for full-spectrum WLEDs.Targeted deep red phosphors(Sr,Gd)Li(AI,Mg)3N4:Eu2+ were designed from the initial model of SrLiAl3N4:Eu2+ by structural modification.The correlations among structural evolution,crystal-field environment,and luminescence properties were elucidated.Replacing Sr2+ with Gd3+in(Sr,Gd)LiAl3N4:Eu2+ leads... 相似文献
20.
A. K. Sharma S. J. Dhoble Jatin Bhatt D. R. Peshwe 《Transactions of the Indian Institute of Metals》2011,64(1-2):213-215
Eu2+ activated phosphors with the composition of Ca013Sr0.87Al2Si2O8 were synthesized by combustion technique. The luminescent properties of these phosphors have been explored by analyzing their excitation and emission spectra with the help of photoluminescence (PL) spectroscopy. The phase-forming processes and presence of associated mode of vibrations of the phosphors were studied by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) respectively. Under ultra-violet (UV) excitation, Ca013Sr0.87Al2Si2O8 phosphors had broad emission spectrum between 418 and 550 nm in the blue-green region of spectra corresponding to 4f65d→4f7 transition of Eu2+ ion. The results show Ca013Sr0.87Al2Si2O8: Eu2+ is a promising host candidate for the phosphors and can be used for improving the efficiency and quality of phosphor-converted white light-emitting diodes. 相似文献