Citric Gel Synthesis and Luminescent Properties of Ce^3＋-Activated SrGa2O4 Phosphor

Ce^3＋-activated SrGa2O4 phosphor was synthesized by a method of citric gel,wherein citric acid served as a chelate agent,and the as-synthesized powder was calcined in a slightly reduced ambient.The crystallization characteristics of the sample varied with the calcining temperature.Compared with the phosphor prepared by the solid-state reaction,the phosphor synthesized by citric gel was calcined at a relatively lower temperature.Consequently,the volatilization of Ga2O3 during high-temperature calcining process was avoided.The typical double-peak emission of Ce^3＋ originated from 2D（5d）→4F5/2（4f）,and 2D（5d）→4F7/2（4f）was observed,and the intrinsic emission of SrGa2O4 host was much restricted.The emission intensity varied with the calcining temperature because the different crystallinity and the optimal concentration of Ce-dopant was determined at 3%.     

Preparation of Nano Y_2O_2S∶Eu Phosphor by Ethanol Assisted Combustion Synthesis Method

Rareearthoxysulfidematerialsexhibithighlumi nescentefficiencyaswellasexcellentchemicalstabili ty.Thesematerialsarewidelyusedasluminescent hostmaterialsofseveralcommerciallyavailablephos phorssuchasredemittingphosphorsforcolortelevi sionpicturetube,X rayphosphors[1],andlongafter glowpigments[2].Thereexistseveralmethodsinpre paringrareearthoxysulfides:(1)Traditionalsulfide fusionmethod,i.e.sulfurationofrareearthoxidein theflux(Na2CO3K2CO3K3PO4)athighte mperature[3,4],whichiswidelyemployedona…     

Luminescence Properties and Site Substitution of Eu~（3＋）and Bi~（3＋） in Me_2Y_8（SiO_4）_6O_2

ＬｕｍｉｎｅｓｃｅｎｃｅＰｒｏｐｅｒｔｉｅｓａｎｄＳｉｔｅＳｕｂｓｔｉｔｕｔｉｏｎｏｆＥｕ~（３＋）ａｎｄＢｉ~（３＋）ｉｎＭｅ_２Ｙ_８（ＳｉＯ_４）_６Ｏ_２ＬｉｎＪｕｎ（林君）；ＬｉＢｉｎ（李彬）（ＩｎｓｔｉｔｕｔｅｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃ?..     

Luminescent Properties of Y_2O_3∶Eu Nanocrystalls Synthesized by EDTA Complexing Sol-Gel Process

Ｎａｎｏｐａｒｔｉｃｌｅｓａｎｄｎａｎｏｃｌｕｓｔｅｒｍａｔｅｒｉａｌｓａｒｅａｎｅｗｃｌａｓｓｏｆａｄｖａｎｃｅｄｍａｔｅｒｉａｌｓｅｘｈｉｂｉｔ ｉｎｇｕｎｉｑｕｅｃｈｅｍｉｃａｌａｎｄｐｈｙｓｉｃａｌｐｒｏｐｅｒｔｉｅｓｃｏｍｐａｒｅｄｔｏｔｈｏｓｅｏｆｔｈｅｉｒｂｕｌｋｍａｔｅｒｉａｌｓ[1 ] .Ｙ2 Ｏ3 :Ｅｕｉｓａｎｅｆｆｉｃｉｅｎｔｒｅｄ ｅｍｉｓｓｉｏｎｐｈｏｓｐｈｏｒｗｈｉｃｈｈａｓｂｅｅｎｕｓｅｄｉｎｆｌｕｏｒｅｓｃｅｎｔｌｉｇｈｔｓ (ＦＬ)ａｎｄｃａｔｈｏｄｅｒａｙｔｕｂｅ (ＣＲＴｓ…     

Luminescent properties of MMgP_2O_7：Eu~（3＋）（M=Ca,Sr,Ba） phosphor

A series of red phosphors Eu3+-doped MMgP2O7(M=Ca,Sr,Ba) were synthesized by solid-state reaction method.X-ray powder diffraction(XRD) analysis confirmed the formation of pure CaMgP2O7,SrMgP2O7 and BaMgP2O7 phase.Photoluminescence spectra of MMgP2O7(M=Ca,Sr,Ba):Eu3+ phosphors showed a strong excitation peak at around 400 nm,which was coupled with the characteristic emission(350-400 nm) from UV light-emitting diode.The CaMgP2O7:Eu3+,SrMgP2O7:Eu3+ and BaMgP2O7:Eu3+ phosphors showed strong emission bands peaking at 612,593 and 587 nm,respectively.Due to the difference of the ion sizes between Ba2+(0.142 nm),Sr2+(0.126 nm),Ca2+(0.112 nm),Mg2+(0.072 nm) and Eu3+(0.107 nm),Eu3+ ions were expected to substitute for different sites in CaMgP2O7,SrMgP2O7 and BaMgP2O7 lattice.     

Sol-Gel Synthesis and Luminescent Characteristic of Doped Eu^3 ＋ Silicate-Silica Phosphor

Silicagelphosphorsdopedrareearthionshave attractedgreatattentionofmanyresearchersdueto theseadvantages,suchashighersamplehomogeneity,purityandstable,efficientandenvironmentallyfriend lyphotoluminescencematrixmaterials,whichisless toxicleadtonetconversione…     

Synthesis and Luminescent Properties of Novel Red Long-Lasting Phosphor Ca2Zn4Ti15O36：Pr^3＋

A novel red long-lasting phosphor Ca2Zn4Ti15O36:Pr were synthesized by solid state reaction and by sol-gel method. It is a new type of Pr^3 -doped titanate red long lasting phosphor. It is difficult to make pure Ca2Zn4Ti15O36 crystalline by solid state reaction and it must be sintered at 1200℃ for 96 h.The analysis results of thermogravimetric curve and Xray powder diffraction revealed that Ca2Zn4Ti15O36 canbe formed by sintering precursor at 700℃ for 12 h,     

Synthesis and Structural Investigation of （LaO）_3BO_3 with Eu~（3＋） as Luminescent Probe

ＳｙｎｔｈｅｓｉｓａｎｄＳｔｒｕｃｔｕｒａｌＩｎｖｅｓｔｉｇａｔｉｏｎｏｆ（ＬａＯ）_３ＢＯ_３ｗｉｔｈＥｕ~（３＋）ａｓＬｕｍｉｎｅｓｃｅｎｔＰｒｏｂｅＰｅｎｇＹｉ＇ａｎ（彭夷安）；ＬｉＱｉｈｕａ（李其华）（ＨｕｎａｎＭｅｄｉｃａｌＣｏｌｌｅｇｅ，Ｃ?..     

Citrate-Gel Synthesis and Luminescent Properties of α-Zn3 （PO4）2 Doped with Eu^3＋

By using inorganic salts as raw materials and citric acid as complexing agent, α-Zn3(PO4)2 and Eu^3 doped α-Zn3( PO4)2 phosphor powders were prepared by a citrate-gel process. X-ray diffraction (XRD), TG - DTA, FF - IR and luminescence excitation and emission spectra were used to characterize the resulting products. The results of XRD reveal that the powders begin to crystallize at 500℃ and pure α-Zn3(PO4)2 phase is obtained at 800℃. And the results of XRD reveal that Eu^3 exists as EuPO4 in the powder. In the phosphor powders, the Eu^3 shows its characteristic red-orange(592 nm, ^5D0 -^7F1) emission and has no quenching concentration.     

Luminescent Properties of Green Phosphor Ca8Mg（SiO4 ）4 Cl2：EU^2＋ , DY^3＋ for LED Applications

The new phosphor calcium magnesium chlorosilicate, codoped with Eu^2＋ and Dy^3＋, was synthesized with the help of the high temperature solid state reaction in reducing atmosphere. The excitation and emission spectra were very similar to that of Ca8Mg（SiO4）4Cl2 ：Eu^2＋, and the Dy^3＋ concentration influenced the emission intensity of this phosphor. The intensity of Eu^2＋ and Dy^3＋ codoped CMSC was stronger than that of Eu^2＋ singly doped CMSC. The emission spectrum of the Dy^3＋ ion overlapped the absorption band of the Eu^2＋ ion, indicating that an energy transfer from Dy^3＋ to Eu^2＋ took place in CMSC：Eu^2＋, Dy^3＋ phosphor. The mechanism of the energy transfer from Dy^3＋ tO Eu^2＋, in this phosphor, might be resonant energy transfer.     

Synthesis of Long Afterglow Phosphor CaAl_2Si_2O_8∶Eu~ (2 ), Dy~(3 ) via Sol-Gel Technique and Its Optical Properties

Inrecentyears,thelongafterglowphotolumines centmaterialhasbeenwidelyusedinmanyfields[1,2].Therareearthionsactivatedsilicatesbasedphosphor isbelievedasapromisinglongafterglowmaterialin thenearfutureforitshighchemicalandphysicalsta bility,especiallytheirwat…     

Synthesis of CaO-SiO_2-B_2O_3∶Sm_2O_3 Glasses and Luminescent Properties of Sm~(3 )

Synthesis of CaO-SiO_2-B_2O_3∶Sm_2O_3 Glasses and Luminescent Properties of Sm~(3 )     

Synthesis of Long Afterglow Phosphor CaAl2Si2O8 ：Eu^2＋, Dy^3＋ via Sol-Gel Technique and Its Optical Properties

The long afterglow phosphor CaAl2Si2O8：Eu^2＋ , Dy^3＋ was prepared by a sol-gel method. The sol-gel process and the structure of the phosphor were investigated by means of X-ray diffraction analysis （XRD）. It is found that the single anorthite phase formed at about 1000 %, which is 300 % lower than that required for the conventional solid state reaction. The obtained phosphor powders are easier to grind than those of solid state method and the partical size of phosphor has a relative narrow distribution of 200 to 500 nm. The photoluminescence and afterglow properties of the phosphor were also characterized. An obvious blue shift occurs in the excitation and emission spectra of phosphors obtained by sol-gel and solid state reaction methods. The change of the fluorescence spectra can be attributed to the sharp decrease of the crystalline grain size of the phosphor resulted from the sol-gel technique.     

Synthesis and Luminescence Properties of Gd_2O_3∶Eu~(3+) Phosphors

Gd2 O3∶Eu3+ isanefficientredemittinglumines centmaterial ,whichcanbeappliedindisplays[1,2 ] .TheconventionalcommercialGd2 O3∶Eu3+ ismainlysynthesizedbyhightemperaturesolid statereactionandchemicalco precipitationmethods .Anadvancedperformanceofdisplaysrequireshighqualityphospho rssuchashighbrightnessandefficiency ,monodisper sityandfinegrainsize .Muchresearchhasanticipatedthatsubmicrometer sizedandnanometerluminescentmaterialswillhavethesepotentialadvantages[3～ 8] ,sosubmicrometer sizedan…     

Effects of Doping Trace Sm~(3+) and Gd~(3+) on Luminescent Character of Y_2O_2S∶Eu~(3+)

Effects of Doping Trace Sm~(3+) and Gd~(3+) on Luminescent Character of Y_2O_2S∶Eu~(3+)     

Photoluminescence properties and effect of Bi~（3＋） dopant of Eu~（3＋） and Dy~（3＋） co-doped Sr_3V_2O_8

Photoluminescence properties of Sr 2.5 Dy 1/3-x Eu x V 2 O 8(x=0,0.06,0.12,0.18,0.24,0.33) were investigated.The excitation spectra included a broad band in the short wavelength region and several sharp lines in the longer wavelength region,and the spectral origin were discussed.The emission spectra were measured in two different exciting ways,i.e.,exciting the VO 4 group at 270 nm and the Eu 3+ ion at 398 nm,respectively,and the energy transferring process was reasonably suggested.Furthermore,multi-color emission could be achieved in Sr 2.5 Dy 1/3-x Eu x V 2 O 8,indicating that the studied samples had potential applications in the white light emitting diodes.Further investigation showed that reducing the concentration of Eu 3+ and Dy 3+ and introducing Bi 3+ as a sensitizer ion greatly enhanced the emission intensity.     

Synthesis and Luminescence of SrZnO2：Eu^3＋, Li^＋ Phosphor by Long Wavelength UV Excitation

SrZnO2 ： Eu^3 ＋ , Li^＋ phosphor powder by long wavelength UV excitation was synthesized by conventional solid-state reaction method. XRD and PL were employed to characterize their properties. The resuits show that Eu^3＋ ions preferentially occupy Sr^2＋ asymmetry cationic sites, thus emitting 612 nm red light originated from ^5D0 to ^7F2 transition. The luminescent intensity can be greatly enhanced with incorporation of Li^＋ ions. The excitation efficiency in range of 350 - 400 nm also increases greatly due to incorporating Li ^＋ ions. SrZnO2 ： Eu^3 ＋ , Li^＋ is a promising redemitting phosphor by long wavelength UV excitation.     

Luminescence and Defect Properties of Novel Bluish-Green Phosphor β-Zn3（PO4）2： Zr^＋

Luminescence and defect properties of novel phosphor β-Zn3 (PO4) 2 : Zr^4 were systematically investigated. Corresponding to its lowest optical absorption transition at 240 nm, phosphor emits a bluish-green light at 485 nm, which yields the Stokes shift about 20000 cm^-1. The unusual optical properties of Zr^4 ion are ascribed to its uncommon coordination environment. In addition it shows intensive bluish-green long lasting phosphorescence (LLP) due to the existence of electron trap, which is generated by aliovalent substitution of Zr^4 ion for the cation site in the matrix as shown in thermoluminescence (TL) spectrum.