Influence of Rare Earth Elements on Luminescent Properties of Y2SiO5 ： Tb

Photoluminescent （PL） and cathodoluminescent （CL） properties of rare earths （Sc^3＋ , La^3＋ , Gd^3＋ and Lu^3＋ ） doped （Y0.97Tb0.03）2SiO5 were studied. Rare earth doping clearly influences PL and CL properties of Y2SiO5 ： Tb. For La^3＋ doped system, PL intensity increases nearly 10 % at x = 0.05 whereas for Lu^3＋ doped system, the intensity increases about 20% at x = 0.20. Gd^3 ＋ doping and Sc^3＋ doping reduce the intensity; at x = 0.3, it is reduced about 30% for Gd^3＋ doped system and about 15 % for Sc^3＋ doped system, respectively. Quenching concentration of activator became higher in rare earth doped samples, which may be understood by that the rare earth dopants might dilute the concentration of the activator. Additionally, doping also influences the color saturation of Y2SiO5 ： Tb. Sc^3＋ , La^3＋ , and Gd^3 doping improve the color saturation, whereas Lu^3＋ doping decreases the color saturation. CL measurements show that CL intensity increases for all rare earths doped systems. The energy transfer from Gd^3＋ to Tb^3＋ was discussed.     

Thermoluminescence Characteristics of SrB_6O_(10)∶Tb

Thermoluminescence(TL)isakindofcommon phenomenoninnatureandhasbeenextensivelyap pliedinradiationdosimetry,archaeologydatingand geology.TLmaterialsdopedwithrareearthssuchas MgB4O7∶Dy TmandCaSO4∶Dyetc.areutilizedasra diationmeasurementinradiationdosimetryfielddueto theircharacteristicsoftissueequivalenceandhigher sensitivity,respectively.However,anidealTLphos phorwithtissueequivalence,highsensitivity,simple glowcurvestructure,andexcellentstability,etc.has notbeenfoundyet.ThepropertiesofT…     

Emission Characteristics of PVK Doped TbY（o-MBA）6（phen）2 Systems

Since the pioneering work of Tang and VanSlykeon organic light emitting diodes(OLEDs)in1987,OLEDs have been particularlyinterestedin because oftheir potential applications in next-generationflat-pan-el displays and large-area flexible displays[1~3].Rareearth complex materials have been widely used incathodoluminescent display phosphor screens,lasersand lamps because their photoluminescence PL ex-hibits high quantumefficiencies and very sharp spec-tral bands.Inthe1990s,Kido et al[4~6]first…     

Study on Spectra of La2CaB10O19：Eu^3＋ in VUV-VIS Range

Excitation and emission spectra of new borate La2CaB10O19 doped Eu^3 in VUV-VIS range, high resolution emission spectra at room temperature and lifetime of Eu^3 were investigated. The emission line at about 616nm attributed to the ^5D0-^7F2 transition of Eu^3 is the most intense emission of Eu^3 . The broad band at about 244nm is originated from charge transition band (CTB) of O^2→Eu^3 . According to the numbers of spectral lines ^5D0-^7F0 and ^5D0-7F1 in highresolution spectrum, Eu^3 ions occupy two crystallographic sites. The lifetimes of ^5D0-^7F0 transition of Eu^3 of two kinds of lattice sites are individually 2.1 and 2.6ms, and both are exponential decay. In the VUV excitation spectrum, complicated band between 130 and 170nm consists of host absorption and f-d transition of Eu^3 .     

Eu^2＋ Luminescence in BaZnAl10O17 ： Eu Phosphor

Eu^2 -doped BaZnAl10O17 phosphor was successfully obtained by coprecipitation method, in which oxalic acid and ammonia were used as precipitants, and precipitates were calcined at 1400 ℃ for 3 h. Its luminescent intensity was much stronger than the one obtained by solid-state reaction at high temperature. According to XRD, the crystal was identified as BaZnAl10O17 with β-Al2O3 structure.     

Site Selective Spectroscopy of Suffactant－Assembled Y2O3：Eu Nanotubes

Y2O3:Eu nanotubes were synthesized by a surfactant assembly mechanism. Under ultraviolet-light excitation,the nanotubes present luminescence properties different from that of Y2O3:Eu nanoparticles. The peak position of the charge transfer band in excitation spectra varies with the monitoring emission peaks, while the emission spectra are dependent on the excitation wavelength. Laser selective spectroscopy was performed to distinguish the local symmetries of the Eu^3 ions in the nanotubes. The results of laser-selective excitation indicate that the emission centers near the surface of nanotube wails exhibit inhomogeneously broadened spectra without spectral structures while the two sites (site B and site C) inside the nanotube walls present resolved spectral structures. It is concluded by the number and peak positions of the spectral lines that the sites B and C possess different site symmetries.     

Luminescent Properties of BaMgAl10O17： Eu2＋ Phosphors Coated with Y2SiO5

BaMgAl10O17： Eu^2＋ phosphors was prepared by the solid-reaction method. Y2SiO5 was coated uniformly on the surface of phosphor by the surface-coated method, and the luminescent and deterioration properties were discussed. The XRD and SEM results show that Y2SiO5 film is produced on the surface of BAM phosphor. The emission spectrum analysis shows that the peak of the phosphor does not change after coating. The two phosphors were applied to lamps and the deterioration was tested at different ignited time. The keep ratio of luminous flux of the phosphor coated with Y2SiO5 is higher than that of the uncoated phosphor.     

Synthesis and Photoluminescence of BaMgAl10O17 ：Eu^2＋ Phosphor by Oxalate Co-precipitation Process

Single phase of Ba1-x MgAl10O17 ： x Eu^2＋ （0.02≤ x ≤ 0. 14） phosphors was first successfully prepared by coprecipitation in aqueous medium with a “reverse strike” method, using oxalic acid and ammonia together as precipitants. Completely crystallized phosphors were obtained at 1300 ℃, which is 300 ℃ lower than the temperature of solid-state reaction. Their photoluminescence was investigated under UV and VUV region, respectively. The emission spectra of Ba1-x MgAl10O17：xEu^2＋ samples excited by 254 or 147 nm showed a characteristic wide band with the peak centred at about 450 454 nm. Optimum emission intensity reached at x = 0.1 and then concentration quenching occurred. The synthesized phosphor shows 10% higher emission intensity than that prepared by solid-state reaction.     

Synthesis and Luminescent Properties of Ce^3＋ , Tb^3＋ Co-Doped ZH4B6O13

Green-photoluminescence material Zn4B6O13: Ce^3 , Tb^3 was first synthesized by spread method of high temperature and solid state reaction, which is cubic crystal system with lattice parameters : a0 =0. 7472 nm, V = 0.4172 nm^3, and structural properties are investigated by XRD. The excitation and emission band of Ce^3 ion singledoped in Zn4B6O13 transfer longer spectra 2.38 ～4.94 kk than in other matrices. Emission band of Ce^3 ion better overlaps with the ^7F6→^5G2,^5D1 ,^5H7 absorption band of Tb^3 . It shows that emission of Tb^3 ion is sensitized by Ce^3 . In Zn4B6O13:Ce^3 , Tb^3 , it is due to the energy transfer mechanism, resonance transfer of electric muhipolax interaction of the dipole-dipole between Ce^3 →Ce^3 and Ce^3 →Tb^3 . The color coordinates of ZB4B6O13: x =0.281, y =0.619. The mean diameter of the particles is 0.23μm.     

Thermoluminescence Characteristics of SrB6 O10:Tb

SrB6O10:Tb phosphor was synthesized by high-temperature solid state reaction. The influences of Ce or Li as a co-dopant, Tb concentration and irradiation dose exposure on TL of SrB6O10:Tb were investigated. Results show that Ce or Li as a co-dopant can not improve the sensitivity of SrB6O10:Tb phosphor. TL response depends on Tb concentration and 0.02 is the optimum in the concentration range from 0.01 to 0.10. Using the optimum Tb concentration, we calculated the kinetic parameters of SrB6O10:Tb employing the peak shape method, and suggestedthe phosphor obeying the second order kinetics. TL emission intensity is linearly dependent on the irradiation dose withinthe dose range of 50 ～ 200 Gy.The characteristic Tb3 ion emission was observed in TL emission spectrum.     

Synthesis and luminescence characteristics of terbium（III） activated NaSrBO3

The thermoluminescence (TL) and photoluminescence (PL) properties of the phosphor NaSrBO 3 :Tb 3+ were reported and discussed. The combustion technique was used for the synthesis of polycrystalline samples of NaSrBO 3 :Tb 3+ . The TL glow curve of the compound had a simple structure with a single peak at 434 K. TL sensitivity of the phosphor was found to be more than that of (LiF:Mg,Cu,P). The TL glow curve was studied as a function of concentration of dopant and dose of gamma ray irradiation. The kinetic parameters of the thermoluminescence of NaSrBO 3 : Tb 3+ were calculated employing the peak shape method. The photoluminescence (PL) properties of Tb 3+ doped in NaSrBO 3 were studied over the 200-400 nm excitation range. The excitation spectra of NaSrBO 3 :Tb 3+ consisted of single narrow band peaking at about 236 nm. The emission spectra monitored at 236 nm excitation consisted of a series of sharp lines peaking at 489, 544, 586 and 622 nm corresponding to the 5 D 4 → 7 F j (j=3,4,5,6) transitions within the 4f 8 configurations of Tb 3+ .     

Synchrotron radiation investigations of the Sr2MgSi2OT：Eu^2＋,R^3＋ persistent luminescence materials

The electronic and defect energy level structure of polycrystalline Sr₂MgSi₂O₇:Eu²⁺,R³⁺ persistent luminescence materials were studied with thermoluminescence and different synchrotron radiation spectroscopies (UV-VUV emission and excitation, X-ray absorption near-edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS)). Special attention was paid on the effect of the R³⁺ co-dopants on the persistent luminescence properties of the materials. Theoretical calculations using the density functional theory (DFT) were carried out simultaneously with the experimental work. The experimental band gap energy (E_g) value of ca. 7.1 eV agreed very well with the DFT value of 6.7 eV. The variation of the E_g value was attempted to relate with the trap structure as well as with the different properties of the R³⁺ co-dopants. The trap level energy distribution depended strongly on the R³⁺ co-dopant except for the shallowest trap energy above the room temperature remaining practically the same, however. The different processes in the mechanism of persistent luminescence from Sr₂MgSi₂O₇:Eu²⁺,R³⁺ were assembled and their contributions discussed.     

Synthesis, crystal structures and characterization of a pair of TbIII-based enantiomers

A pair of novel Tb^III-based enantiomers, [Tb(dbm)₃·L_SS] (1) and [Tb(dbm)₃·L_RR] (2) (where L_SS=(+)-4,5-pinene bipyridine, L_RR= (-)-4,5-pinene bipyridine, dbm=dibenzoylmethanate), were synthesized and characterized based on single crystal X-ray diffraction, elemental analysis, FT-IR, TG and CD spectra. X-ray diffraction analysis showed that both the complexes crystallized in monoclinic crystal system with P2₁ chiral space group. The Tb^III ion was eight-coordinated by six O atoms of three dbm ligands and two N atoms from one chiral ligand L_SS or L_RR. The CD spectra revealed that complexes 1 and 2 were enantiomers. Thermogravimetric analysis results indicated that 1 and 2 were thermally stable up to 246 °C.     

Novel Terbium Chelate Doped Fluorescent Silica Nanoparticles

Novel terbium chelate doped silica fluorescent nanoparticles were prepared and characterized. The preparation was carried out in water-in-oil （W/O） microemulsion containing monomer precursor （pAB-DTPAA-APTEOS）, Triton X-100, n-hexanol, and cyclohexane by controlling copolymerization of tetraethyl orthosilicate and 3-aminopropyl-triethyloxysilane. The nanoparticles are spherical and uniform in size, about 30 nm in diameter, strongly fluorescent, and highly stable. The amino groups directly introduced to the surface of the nanoparticles using APTEOS during preparation made the surface modification and bioconjugation of the nanoparticles easier. The nanoparticles are expected as an efficient timeresolved luminescence biological label.     

Organic Light Emitting Devices Based on Terbium Complex

Rare earth complex Tb(BA)3phen was synthesized, which is first used as an emitting material in electroluminescence. The properties of monolayer device with the swing film rate of 1000 r·min-1(70 nm) and the weight ratio of 1:5(PVK:Tb(BA)3phen) are the best. And the highest brightness of this device reached 26.8 cd·cm-2 at a fixed bias of 21 V. Bright green emission could be obtained from the optimized double-layer device and the highest EL brightness of the device reached 322 cd·m-2 at the voltage of 22 V.     

Study on Photochemical Fluorescence Enhancement of Terbium-Fleroxacin Complex

Ｆｌｅｒｏｘａｃｉｎ (ＦＬＲＸ)ｉｓｏｎｅｏｆｔｈｅｓｙｎｔｈｅｔｉｃｆｌｕｏｒｏｑｕｉｎｏｌｏｎｅａｎｔｉｂａｃｔｅｒｉａｌａｇｅｎｔｓ ,ｗｈｉｃｈｈａｓｂｅｅｎｕｓｅｄｉｎｃｌｉｎｉｃｔｒｅａｔｍｅｎｔｂｅｃａｕｓｅｏｆｉｔｓｈｉｇｈａｃｔｉｖｉｔｙａｇａｉｎｓｔｖａｒｉｏｕｓｂａｃｔｅｒｉａ[1] .Ｓｏ ,ｉｔｉｓｉｍｐｏｒｔａｎｔｔｏｄｅｔｅｒｍｉｎｅｉｔｓｃｏｎｔｅｎｔｓｉｎｂｏｄｙｆｌｕｉｄｓ .Ａｔｐｒｅｓｅｎｔ,ｔｈｉｓｉｓｕｓｕａｌｌｙｐｅｒｆｏｒｍｅｄｂｙｈｉｇｈ ｐｅｒｆｏｒｍａｎｃ…     

Preparation of Incompact Strontium Aluminate Phosphors

The incompact long afterglow pigment SrAl2O4: Eu, Dy was synthesized by ceramics technology.The agglomerated starting raw material had little effect on the synthesis of SrA12O4 matrix through solid-state reaction method,but the shrinkage and densification was retarded greatly by the agglomerated powder by the formation of large and extensive pore network.The sintering mechanism is surface diffusion ( without flux B2O3 ) and grain boundary diffusion (with B2O3 as flux)respectively, and the as-prepared long afterglow pigment glows in the dark for over 4000 min.