Synthesis and luminescent properties of novel Ba2−xEuxZr2−yHfySi3O12 phosphor

A series of Eu²⁺ activated luminescent materials according to the composition of Ba_2−xEu_xZr_2−yHf_ySi₃O₁₂ were synthesized using a high temperature solid-state reaction method starting from metal oxides and carbonates. Single phase powders were obtained using two annealing steps and boric acid as a flux. Firstly, starting materials were sintered at 1450 °C for 5 h under CO atmosphere and subsequently annealed at 1200 °C for 5 h under N₂/H₂ (95%/5%) gas flow. All samples were characterized by powder X-ray diffraction (XRD) analysis, thermal quenching (TQ), fluorescence lifetime measurements and photoluminescence (PL) techniques. Moreover, emission colour points, luminous efficacies and quantum efficiencies (QE) were calculated and discussed as a function of Eu²⁺ concentration and Zr/Hf ratio of the host lattice.     

钒硼酸钇铕荧光粉的真空紫外光谱特性研究

采用高温固相法合成了YBχV1-χO4-χ：Eu^3＋荧光粉,利用XRD变温发射光谱以及真空紫外激发的光谱对其进行研究。结果表明,在147nm的真空紫外光激发下,荧光粉的发射主峰位于619nm,与（Y,Gd）BO3：Eu^3＋相比,色纯度较好,发光亮度达86％,是彩色PDP用红色荧光粉的候选材料。     

共沉淀法制备PDP荧光粉Y0.95Eu0.05AlO3

以氯化物为原料,氨水和碳酸氢铵作复合沉淀剂,采用共沉淀法合成Y0.95Eu0.05AlO3荧光粉.利用电子扫描电镜以及真空紫外激发下的发射光谱对其进行表征.结果表明,共沉淀法合成的Y0.95Eu0.05AlO3荧光粉粒径约为5μm,粒度较均匀,在真空紫外线147 nm激发下的发射主峰位于615 nm处.     

Dy3+激活的几种硼酸盐在VUV-VIS范围的光谱性质

本文报道了SrAl2B2o7:Dy^3 、BaAl2B2O7:Dy^3 、SrAl3BO7:Dy^3 、La2CaB10O19:Dy^3 的紫外－真空紫外（UV－VUV）激发光谱和UV激发下的发射光谱。根据发射光谱讨论了Dy^3 离子在这几种基质中发光的黄蓝比（Y／B）。在VUV激发光谱中推测了Dy^3 的f-d跃迁及电荷迁移态（CTS）和基质吸收的位置。     

Functionalization of Polymer Surfaces Using Excimer VUV Systems and Silent Discharges. Application to Electroless Metallization

New approaches for electroless plating of nonconductive polymers or polymer-based materials are described. In this work, polyimide substrates were surface-functionalized (i) in nitrogenated (ammonia at reduced pressure) and oxygenated (air at atmospheric pressure) atmospheres under assistance of vacuum-ultraviolet (VUV) irradiation (use of a xenon silent discharge excimer source) or (ii) directly in air at atmospheric pressure using a dielectric-barrier discharge (DBD) device. After functionalization, the substrates were “activated” by dipping in a dilute acidic PdCl₂ solution or by spin-coating of a thin metal-organic film (from a solution of palladium acetate (PdAc) in chloroform). The catalytic activity of the so-deposited palladium species toward the electroless deposition of nickel was studied before and after a VUV post-irradiation (in air at atmospheric or reduced pressure) with a view to understanding better the role of the reducer (sodium hypophosphite) within the electroless bath.

This work confirms the specific interest of grafting nitrogenated functionalities onto polymer surfaces for attaching covalently the palladium-based catalyst (in particular in the case of the PdCl₂ route), forming thus strong Pd - N - C bonds at the metal/polymer interface. This results from the strong chemical affinity of palladium toward nitrogen. On the other hand, when oxygenated functionalities are surface-grafted, the conventional two-step procedure using SnCl₂ and PdCl₂ solutions can be proposed due to the strong chemical affinity of tin toward oxygen. The Ni deposits obtained under these different conditions pass the standard Scotch^®-tape test and, therefore, exhibit a good practical adhesion. For this same purpose, it is interesting to note that the DBD treatment operating in air at atmospheric pressure causes an increase of the surface roughness and, therefore, an improvement in adhesion of metallic films when their initiation is catalyzed through the PdAc route. In addition, this work demonstrates that extensive research still has to be performed to understand and improve the Ni/polymer adhesion when the PdAc route associated with a VUV irradiation is considered.     

Synthesis of Spherical （Y, Gd） BO3 ： Eu^3＋ Phosphor Using W/O Emulsion System

Spherical （Y, Gd）BO3：Eu^3＋ phosphor particles with a narrow size distribution（2 -4 μm） was obtained by firing the Y-Gd-Eu-BO3 precursor prepared in a W/O style emulsion system. In the W/O emulsion system, kerosene, used as oil phase, was mixed with Span 80 and Tween 80 compounds which were employed as the emulsifier with an HLB （hydrophile-lipophile balance） value of 5.2- 5.3. Both rare earths （Y, Gd and Eu） nitrate and boric acid solution or ammonia solution were used as aqueous phase. The synthesis conditions, such as emulsion composition, emulsifying style, precipitation reaction process, reaction temperature, morphology control, and so on, were investigated, and the optimum synthesis conditions for preparing spherical （Y, Gd）BO3：Eu^3＋ phosphor was obtained. The phosphor was characterized by XRD, SEM, laser particle size analysis, emission and excitation spectrum under vacuum ultraviolet （VUV）, and so on. The phosphor synthesized using the water-in-oil emulsion method with median diameter （D50） of 2 - 4 μm shows agreeable photoluminescence （PL） property and sphericity. The main emission peak appears at about 593 nm, which corresponds to ^5D0→^7F1 transition （magnetic-dipole transition） of the Eu^3＋ ion. The cell parameters and powder diffraction data were indexed. The structure of the phosphor belongs to the hexagonal system with space group P63/m.     

High and low spin energy states of the Tb 4f5d configuration in BaF2

In this paper we present results of detailed spectroscopic studies of Tb³⁺ luminescence from BaF₂:0.075 mol% Tb performed at Superlumi station of Hasylab, DESY, Hamburg and at Institute of Physics, N. Copernicus University, Torun, Poland (IF UMK Torun).We have measured UV/VUV excitation spectra of the dominant blue Tb³⁺ luminescence and emission spectra under excitation into various bands found from the excitation spectra. The excitation spectra are dominated by the two well known broad bands due to the parity and spin-allowed (SA) 4f⁸ → 4f⁷5d transitions. The higher energy triple t-band and unresolved single e-band at lower energies are widely separated (10 Dq about 16,500 cm⁻¹) reflecting the single d-electron energy in the high symmetry cubic crystal field with a relatively low contribution from the low symmetry component.In addition to these bands we have also detected a number of weaker bands at lower energy sides of both dominant SA bands. While the structured band with components at 252.8, 252.3, 250.4 and 248.4 nm clearly corresponds to the SF (spin-forbidden) band found earlier in LiYF₄:Tb, the bands at 183, 178 and 172 nm have been never, to the best of our knowledge, reported before. We present arguments that these new bands are the SF counterparts of the triple SA t-band at about 158 nm. The d-f exchange energies for d(e) and d(t) electrons are different at 7779 and 8245 cm⁻¹, respectively.Although the energy levels corresponding to the identified high and low spin (HS and LS) states of the 4f⁷5d configuration are, in BaF₂, well separated, there are no SA nor SF transitions generating d-f emission in BaF₂:Tb. This is because the numerous 4f⁸ energy levels intercept the excitation energy from 4f⁷5d levels leading to the well known blue and green Tb³⁺ 4f⁸ emissions.     

VUV spectroscopy and low temperature thermoluminescence of LSO:Ce and YSO:Ce

Radioluminescence and UV-excited photoluminescence spectra, photoluminescence time profiles, thermoluminescence glow curves and gamma-excited energy spectra (determining scintillation light yields) of several Lu₂SiO₅:Ce and Y₂SiO₅:Ce samples were recorded. The results are analyzed with attention focused on possible correlations between trap distributions, VUV responses, and light yields. The aspect of two distinct sites occupied by Ce³⁺ ions is also discussed.     

氟化氪真空紫外辐射的观察

实验观察到一种新的离子准分子──氟化氪离子准分子产生的真空紫外连续谱辐射，其峰值位于１４８ｎｍ处。实验结果与理论计算值符合很好。     

彩色PDP中几种工作气体和荧光粉对提高发光效率的作用

彩色ＰＤＰ的发光效率在很大程度上与工作气体和荧光粉有关。本文比较了三种系列潘宁气体的真空紫外辐射性能和七种真空紫外荧光粉的激发和发射性能，择其应用于ＡＣＰＤＰ。测试表明，当气体以合理配比和充气压放电产生的共振辐射线与三基色荧光粉激发和发射性能匹配时，可获得高的发光效率。文中还根据发光效率公式提出对研制荧光粉的要求。