三聚氰胺/Tb~(3+)插层的聚二炔纳米片的制备及其热致变色可逆性研究（英文）

聚二炔(PDA)是一类具有层状结构的共轭聚合物.在插层过程中,客体组分可插入PDA的层间,形成插层结构.在这些结构中,一部分插层复合物具有近乎完美的组装结构,并展现出完全可逆的热致变色特性.迄今为止,已报到的具有近乎完美组装结构的P D A复合物中仅成功插入了单个客体组分.本文选择其一侧的羧基可与Tb~(3+)离子或三聚氰胺(MAs)作用的10,12-二十五烷二炔酸(PCDA)作为单体.当PCDA,MA和Tb~(3+)投料摩尔比为3:267:1时,虽然体系中存在大大过量的MA,仅有Tb~(3+)离子插入了PDA层间,该复合物具有近乎完美插层结构,表现出完全可逆的热致变色特性.当PCDA,MA和Tb3+投料摩尔比为3:267:0.6时,此时Tb~(3+)和MAs都插入了PDA的层间,该复合物存在近乎完美的结构区域和一些不完美的缺陷区域(例如:MA插层区域以及区域-区域边界处).因此,其仅表现出部分可逆的热致变色特性.其近乎完美的结构区域中的共轭主链仍能可逆地恢复至其初始构象,而缺陷区域的共轭主链则很难可逆地恢复至其初始构象.     

窄谱带绿色有机电致发光器件

以Tb³⁺:水杨酸(Tb³⁺:(SA)₃)为空穴传输层兼发光层、高荧光材料Alq₃为电子传输层,得到了窄谱带的绿色有机薄膜电致发光双层结构器件.实验证实,双层器件的电致发光是电荷载流子隧穿内界面(Tb³⁺:(SA)₃/Alq₃)之后分别在两有机层内的复合发光,是两有机层本征发光的叠加.其光谱随着电子传输层厚度而改变,因而减少电子传输层厚度能得到亮度高、稳     

新型光存储材料Sr2SnO4: Tb3+, Li+ 的合成及其红外上转换光激励发光性能的研究

采用高温固相法获得了一种只具有 微弱余辉的新型电子俘获型光存储材料Sr₂SnO₄:Tb^{3 +}, Li ⁺. 发光性能研究结果表明: 该材料对980 nm的红外激光具有很好的上转换光激励信息读出响应, 同时292 nm紫外光为其最佳信息写入光源. 光存储性能研究结果表明: 该材料的浅陷阱较少, 因此其余辉发光很弱, 不到500 s; 另一方面, 该材料中存在大量的深蓄能陷阱. 因此, Sr₂SnO₄: Tb^{3 +}, Li⁺是一种具有较好实际应用价值的新型电子俘获型光存储材料. 此外, 还讨论了Sr₂SnO₄: Tb^{3 +}, Li⁺的光存储发光机理.     

热致可逆变色的聚二炔/稀土离子纳米复合物

将Dy⁺或Sm⁺掺杂到具有层状结构的10,12-二十五碳二炔酸(PCDA)纳米粒子中,得到二炔酸/稀土离子(PCDA-RE)纳米复合物．随后在稍微高于二炔酸熔点的温度下对PCDA-RE纳米复合物进行退火处理,退火后的PCDA-RE纳米复合物发生拓扑聚合反应得到聚二炔酸/稀土离子(PDA-RE)纳米复合物．虽然纯聚二炔酸的热致变色过程是不可逆的,但是PDA-Sm纳米复合物和PDA-Dy纳米复合物分别具有不完全和完全热致可逆变色的性能．研究表明,PDA-RE纳米复合     

Eu2+,Mn2+在BaZnP2O7中的发光及Eu2+→Mn2+能量传递

采用高温固相法合成了BaZnP₂O₇:Eu²⁺,Mn²⁺荧光粉，并对其发光性质及Eu²⁺对Mn²⁺的能量传递机理进行了研究.Eu²⁺和Mn²⁺在380 nm和670nm的发射峰分别由Eu²⁺的5d—4f跃迁和Mn²⁺的⁴T₁(^{4相似文献}   

Tb3+掺杂硅酸盐玻璃发光性能的浓度依赖关系

 利用高温熔融法制备了不同浓度的Tb³⁺掺杂硅酸盐玻璃,并分别测量了紫外和X射线激发时的发射光谱。光谱结果表明,不同浓度Tb³⁺掺杂硅酸盐玻璃在紫外和X射线激发时发光行为具有相似的浓度依赖关系：低浓度Tb₄O₇掺杂时主要以蓝光(5D₃→⁷FJ)发射为主,而高浓度掺杂时以绿光(⁵D₄→⁷FJ)发射为主。Tb³⁺发光强度与掺杂浓度的关系分析表明,⁵D₃的浓度猝灭是电偶极-电偶极相互作用引起的, 而⁵D₄的浓度猝灭是交换相互作用引起的。     

Er3+/Yb3+共掺碲钨酸盐玻璃的光谱性质和热稳定性的研究

制备了Er³⁺和Yb³⁺共掺的碲钨酸盐玻璃样品65TeO₂-25 WO₃-10R_mO_n(R_mO_n=PbO,BaO),(65+x)TeO₂-(25-x)WO ₃-10La₂O₃ (x=0,5,10), (60+x)TeO₂-(30 -x)WO₃-10Bi₂O₃ (x=0,5,10).测试了玻璃样品的吸收光谱、荧光光谱、能级寿命及热稳定性能.结果表明除含Bi ₂O₃的碲钨酸盐玻璃外，其余玻璃样品均没出现析晶开始温度(T_x)，说明碲钨酸盐 是一种适合于光纤拉制的玻璃基质材料.应用Judd-Ofelt理论计算了强度参数Ω_t(t=2, 4,6)，研究表明Ω₂在碲钨酸盐玻璃中主要受到Er-O键的共价性的影响，而Er^{3 +} 离子周围配位场的非对称性影响可以忽略.测得了Er³⁺在15 μm发射谱的荧光 半高宽 (FWHM=71—77nm)和Er³⁺的⁴I_13/2能级寿命 (τ^m=3—34 ms).应用McCumber理论计算了Er³⁺在15 μm处的受激发射截面(σ^peak=068—103×10^-20 cm²).比较了Er³⁺在不同玻璃基质里 的15 μm荧光带宽和发射截面，研究结果表明碲钨酸盐玻璃是一种制备宽带光纤放大器的理想基质材料.     

纳米晶ZrO2:Er3+-Yb3+的制备及其室温上转换发射

用化学共沉淀法制备了ZrO₂:Er³⁺-Yb³⁺纳米晶粉体，所制备的纳米晶粉体具有较强的室温上转换发射和红外发射.研究了样品的晶体结构和上转换发光性质随着Yb³⁺掺杂浓度和煅烧温度的变化关系.通过X射线衍射谱分析发现，经800℃煅烧2h后得到的ZrO₂:Er³⁺-Yb³⁺纳米晶是四方相和单斜相的混合结构，经950℃煅烧2h后得到的样品以单斜相为主，随着Y     

Gd2O3:Eu3+纳米晶的燃烧合成及光致发光性质

采用柠檬酸作燃烧剂用燃烧合成法制备了Gd₂O₃:Eu³⁺纳米晶.用X射线衍射仪(XRD)、高分辨透射电子显微镜(HRTEM)和荧光分光光度计等对Gd₂O₃:Eu³⁺纳米晶的结构、形貌和发光性能进行了分析.结果表明：不同柠檬酸与稀土离子配比(C/M)制备的样品经800℃ 退火1 h后，均得到了纯立方相的Gd₂O₃:Eu³⁺纳米晶，晶粒尺寸约为30 nm，尺寸分布较窄，其中以C/M=1.0时制备的纳米晶结晶性最好，发光强度最大.Gd₂O₃:Eu³⁺纳米晶主发射峰位置均在612 nm处 (⁵D₀→⁷F₂跃迁)，激发光谱中电荷迁移态发生红移，观察到Gd³⁺向Eu³⁺的有效能量传递.对柠檬酸与稀土离子配比(C/M)对结晶度、发光性质等的影响也进行了分析和讨论.     

Al2O3:V3+晶体局域结构及其自旋哈密顿参量研究

提出了解释掺杂离子局域结构畸变的配体平面移动模型，建立了此模型下晶体微观结构与自旋哈密顿参量之间的定量关系.在考虑自旋与自旋、自旋与另一电子轨道和轨道与轨道作用等微小磁相互作用的基础上，采用全组态完全对角化方法，对Al₂O₃晶体中V³⁺的局域结构和自旋哈密顿参量进行了系统的研究.结果表明，V³⁺掺入Al₂O₃晶体后，上下配体氧平面间距离增大了0.0060 nm.从而成功地解释了Al₂O₃:V³⁺晶体的自旋哈密顿参量.在此基础上，研究了三角晶场下3d²离子自旋哈密顿参量的微观起源.研究发现，自旋三重态对自旋哈密顿参量的贡献是主要的，微小磁相互作用对自旋哈密顿参量的贡献只与自旋三重态有关.     

Luminescence of Mn ions in Tb3Al5O12 garnet

The paper is dedicated to investigation of the Mn²⁺ luminescence in Tb₃Al₅O₁₂ (TbAG) garnet, as well as the processes of excitation energy transfer between host cations (Tb³⁺ ions) and activators (Mn²⁺ and Mn²⁺-Ce³⁺ pair ions) in single crystalline films of TbAG:Mn and TbAG:Mn,Ce garnets which can be considered as promising luminescent materials for conversion of LED's radiation. Due to the effective energy transfer between TbAG host and activator, Mn²⁺ ions in TbAG possess the bright orange luminescence in the bands peaked at 595 nm with a lifetime of 0.64 ms which are caused by the ⁴T₁→⁶A₁ radiative transitions. The simultaneous process of energy transfer is realized in TbAG:Mn,Ce: (i) from Tb³⁺ to Mn²⁺ ions; (ii) from Tb³⁺ cations to Ce³⁺ ions and then partly to Mn²⁺ ions through Tb³⁺ ion sublattice and Ce-Mn dipole-dipole interaction.     

Luminescent properties of (Y,Gd)BO3:Bi,RE (RE=Eu, Tb) phosphor under VUV/UV excitation

Bi³⁺- and RE³⁺-co-doped (Y,Gd)BO₃ phosphors were prepared and their luminescent properties under vacuum ultraviolet (VUV)/UV excitation were investigated. Strong red emission for (Y,Gd)BO₃:Bi³⁺,Eu³⁺ and strong green emission for (Y,Gd)BO₃:Bi³⁺,Tb³⁺ are observed under VUV excitation from 147 to 200 nm with a much broader excitation region than that of single Eu³⁺-doped or Tb³⁺-doped (Y,Gd)BO₃ phosphor. Strong emissions are also observed under UV excitation around 265 nm where as nearly no luminescence is observed for single Eu³⁺-doped or Tb³⁺-doped (Y,Gd)BO₃. The luminescence enhancement of Bi³⁺- and RE³⁺-co-doped (Y,Gd)BO₃ phosphors is due to energy transfer from Bi³⁺ ion to Eu³⁺ or Tb³⁺ ion not only in the VUV region but also in the UV region. Besides, host sensitization competition between Bi³⁺ and Eu³⁺ or Tb³⁺ is also observed. The investigated phosphors may be preferable for devices with a VUV light 147-200 nm as an excitation source such as PDP or mercury-free fluorescent lamp.     

Intense ultraviolet upconversion luminescence of Yb and Tb co-doped glass ceramics containing SrF2 nanocrystals

The preparation and upconversion luminescence properties of the Yb³⁺ and Tb³⁺ co-doped glass ceramics containing SrF₂ nanocrystals were investigated. The formation of SrF₂ nanocrystals was confirmed by X-ray diffraction and transmission electron microscopy. Both microstructural and spectral analysis indicated that the Yb³⁺ and Tb³⁺ ions were enriched in the precipitated SrF₂ nanocrystals, which provide much lower phonon vibration energy than the glass matrix. Due to the efficient cooperative sensitization from Yb³⁺ to Tb³⁺ and the relatively low maximum phonon energy of SrF₂ nanocrystals, the Yb³⁺ and Tb³⁺ co-doped glass ceramics exhibited intense upconversion luminescence, including ultraviolet emission at 382 nm.     

Effect of Eu,Tb codoping on the luminescent properties of Y2O3 nanorods

Red-emitting Y₂O₃:Eu³⁺ and green-emitting Y₂O₃:Tb³⁺ and Y₂O₃:Eu³⁺, Tb³⁺ nanorods were synthesized by hydrothermal method. Their structure and micromorphology have been analyzed by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). The photoluminescence (PL) property of Y₂O₃:Eu³⁺,Tb³⁺ phosphor was investigated. In the same host (Y₂O₃), upon excitation with ultraviolet (UV) irradiation, it is shown that there are strong emissions at around 610 and 545 nm corresponding to the forced electric dipole ⁵D₀-⁷F₂ transition of Eu³⁺ and ⁵D₄-⁷F₅ transition of Tb³⁺, respectively. Different qualities of Eu³⁺and Tb³⁺ ions are induced into the Y₂O₃ lattice. From the excitation spectrum, we speculate that there exists energy transfer from Tb³⁺ to Eu³⁺ ions .The emission color of powders reveals regular change in the separation of light emission. These powders can meet with the request of optical display material for different colors or can be potentially used as labels for biological molecules.     

White light generation through the zinc metaphosphate glass activated by Ce, Tb and Mn ions

The photoluminescence of Ce³⁺, Tb³⁺ and Mn²⁺ ions was investigated in the Zn(PO₃)₂ glass. The blue and green emissions of Tb³⁺ ions and the red emission of Mn²⁺ ions are enhanced upon UV excitation through a non-radiative energy transfer from Ce³⁺ to Tb³⁺ and Mn²⁺ ions. The efficiency of this transfer was estimated in at least 62%. It is demonstrated that this glass activated with three ions (Ce³⁺, Tb³⁺ and Mn²⁺) can generate white light emission (x=0.420 and y=0.423 chromaticity coordinates and 3440 K colour temperature) under excitation at 254 nm, i.e., using an AlGaN-based LED as excitation source.     

Preparation and luminescence properties of Tb doped ZrO2 and BaZrO3 phosphors

ZrO₂:Tb³⁺ and BaZrO₃:Tb³⁺ powders are prepared by combustion synthesis method and the samples were further heated to 500, 700 and 1000 °C to improve the crystallinity of the materials. The structure and morphology of materials have been examined by X-ray diffraction, Raman spectra and scanning electron microscopy. It is remarkable that all the samples of ZrO₂:Tb³⁺ and BaZrO₃:Tb³⁺ have similar morphology. These images exhibited homogeneous aggregates of varying shapes and sizes, which are composed of a large number of small cuboids and broken cuboids. The cuboids and broken cuboids size of all the samples are less than 0.5 μm. Photoluminescence for both materials increases with increase of temperature and found maximum for the samples heated to 1000 °C with 5 mole% doping of Tb³⁺ ions. Luminescence is almost double for the zirconia compared to that of barium-zirconate.     

Low temperature quenching and high efficiency Tm, La or Tb co-doped CaSc2O4:Ce phosphors for light-emitting diodes

Low temperature quenching and high efficiency CaSc₂O₄:Ce³⁺ (CSO:Ce³⁺) phosphors co-doped with Tm³⁺, La³⁺ and Tb³⁺ ions were prepared by a solid state method and the phase-forming, morphology, luminescence and application properties of these phosphors were investigated. The results showed that co-doping of Tm³⁺, La³⁺ and Tb³⁺ ions can improve the luminescence properties and decrease temperature quenching of CSO:Ce³⁺ phosphor remarkably. High efficiency green-light-emitting diodes were fabricated with the prepared phosphors and InGaN blue-emitting (∼460 nm) chips. The good performances of the green-light-emitting LEDs made from co-doped CSO:Ce³⁺ phosphors confirm the luminescence enhancement and indicate that Tm³⁺, La³⁺ and Tb³⁺ co-doped CSO:Ce³⁺ phosphors are suitable candidates for the fabrication of high efficiency white LEDs.     

Photoinduced energy transfer from the triplet state of naphthalene moiety in the Tb/Eu complexes of a specially designed naphthalene cryptand

The paper reports time-resolved emission and energy transfer (ET) studies of metal ion complexes of a specially designed rigid macrocyclic naphthalene cryptand (L) under different conditions. Complex formation of L with Li⁺ and H⁺ causes an appreciable increase in singlet state quantum yield and lifetime of L implying photoinduced electron transfer (PET) from the cryptand moiety to naphthalene unit in the free L. The system exhibits photoinduced ET at 77 K in its Tb³⁺ and Eu³⁺ complexes with either NO₃⁻¹ or Cl⁻¹ as counter-anion. The extent of ET is higher for the Tb³⁺ complex as compared to that for the Eu³⁺ complex. In both Tb³⁺ and Eu³⁺ complex, the NO₃⁻¹ ions influence the relative orientation of donor (L) and acceptor (Ln³⁺) more in favour of ET than the Cl⁻¹ ions. The rate constants for the ET from the naphthalene moiety of L to the acceptor (Ln³⁺) have been evaluated at 77 K. The results suggest ET from the triplet state of naphthalene using an exchange mechanism. The ground state geometries of the system L and its complexes with Li⁺, Cs⁺ and Tb³⁺ have been determined using DFT methods to interpret our results.     

Photoluminescence properties of Tb in porous silicon

Terbium (Tb³⁺)/porous silicon (PS) nanocomposites have been formed by impregnation of PS layer in chloride solution of terbium. Complete and uniform penetration of Tb³⁺ into PS layer is confirmed by Rutherford backscattering spectrometry (RBS) study. Photoluminescence (PL) spectrum shows that Tb³⁺ ions emit highly in the green region, while the PL band of PS is quenched. The emission of Tb³⁺ ions depends strongly on the excitation energy and shows a high efficiency at 488 nm corresponding to the maximum absorption band in terbium. A systematic study of the PL versus annealing temperature was performed. It shows an important improvement of the PL intensity for 700°C temperature annealing.