Preparation, patterning and luminescent properties of oxyapatite La-9.33(SiO6)(4)O-2 : A (A = Eu3+, Tb3+, Ce3+) phosphor films by sol-gel soft lithography

Silicate oxyapatite La-9.33 (SiO6)(4)O-2:A (A = Eu3+, Tb3+ and/or Ce3+) phosphor films and their patterning were fabricated by a sol-gel process combined with soft lithography. X-ray diffraction (XRD), Fourier transform infrared spectroscopy, atomic force microscopy, optical microscopy and photoluminescence spectra, as well as lifetimes, were used to characterize the resulting films. The results of XRD indicated that the films began to crystallize at 800degreesC and the crystallinity increased with the increase in annealing temperatures. Transparent nonpatterned phosphor films were uniform and crack-free, which mainly consisted of rodlike grains with a size between 150 and 210 nm. Patterned thin films with different bandwidths (20, 50 mum) were obtained by the micromoulding in capillaries technique. The doped rare earth ions (Eu3+, Tb3+ and Ce3+) showed their characteristic emission in crystalline La-9.33(SiO6)(4)O-2 phosphor films, i.e. Eu3+ D-5(0)-F-7(J) (J = 0, 1, 2, 3, 4), Tb3+ D-5(3,4)-F-7(J) (J = 3, 4, 5, 6) and Ce3+ 5d (D-2)-4f (F-2(2/5), F-2(2/7)) emissions, respectively. Both the lifetimes and PL intensity of the Eu3+, Tb3+ ions increased with increasing annealing temperature from 800 to 1100 degreesC, and the optimum concentrations for Eu3+, Tb3+ were determined to be 9 and 7 mol% of La3+ in La-9.33(SiO6)(4)O-2 films, respectively. An energy transfer from Ce3+ to Tb3+ was observed in the La-9.33(SiO6)(4)O-2:Ce, Tb phosphor films, and the energy transfer efficiency was estimated as a function of Tb3+ concentration.

Geometries and electronic properties of AunPdm (n=1-4, m =-1, 0, 1) clusters

Possible conformers for AunPdm (n = 1-4, m = -1, 0, 1) clusters have been presented and studied by use of density functional theory. The results indicate that for n = 2, linear conformer with C-infinityv symmetry is the most stable for anion species, while for cation and neutral species, conformer with C-2v symmetry is the most stable. For n = 3, 4, conformers with C-2v symmetry (kite-shape) are energetically favored. The calculated electron affinities (EAs) and vertical detachment energies (VDEs) are in good agreement with experiments for n = 1-4. It is also interesting to note that for even n (n = 2, 4), the most stable conformers do not give the best agreement between calculated and experimental EA and VDE values, while for odd n (n = 3), the lowest energy conformer also gives the best agreement. The ionization potentials (IPs) of AunPd clusters are calculated as well.

A novel way to enhance electroluminescence performance based on soluble binary and ternary europium 1,1,1-trifluoroacetylacetonate

Five rare earth complexes (Gd(acae)(3), Gd(TFacaC)(3), Eu(acaC)(3), Eu(TFacaC)(3) and Eu(TFacaC)(3)bipy; acac, acetylacetone; TFacac, 1,1,1-trifluoroacetylacetone; bipy, 2,2'-bipyridyl) were synthesized. By comparing the phosphorescence spectra of Gd(acac)(3) and Gd(TFacac)(3) the effect of the replacement of hydrogen by fluorine was examined. Organic light-emitting devices (OLEDs) based on the corresponding europium complexes as emissive layers were also fabricated by the spin-coating method. The triple-layer-type device with the structure glass substrate/ITO (indium-tin oxide)/PVK [poly(N-vinylcarbazole)]/(PVKEu)-Eu-.(TFacac)(3)bipy:PBD[2-(4-bibipyyl)-5-(4-t-butylbipyl-1,3,4-oxadiazole)]/PBD/Al (aluminum) exhibits a brighter red luminescence than those devices with Eu(acac)(3) and Eu(TFacac)(3) complexes as emissive centers upon applying a d.c. voltage.

Red electroluminescent device with europium 1,1,1-trifluoroacetylacetonate complex as emissive center

By comparing the phosphorescence spectra of Gd(acac)(3) (acac: acetylacetone) and Gd(TFacac)(3) (TFacac: 1, 1, 1-trifluoro-acetylacetone), the effect of fluorine replacing of hydrogen was discussed. It can lower the triplet state energy of acac and make it more suitable to the D-5(1) energy state of europium. Organic electroluminescent (OEL) devices with corresponding europium complexes as emissive layers were fabricated. A triple laver-type device with a structure of glass substrate/indium-tin oxide (ITO)/poly(N-vinylcarbazole) (PVK)/PVK:Eu(TFacac)(3)phen:2-(4-biphenyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (PBD)/PBD/Al exhibits bright red luminescence upon applying dc voltage, The device has the properties of a diode and the current-bias voltage line was obtained.

La_(4-x)(P_2O_5)_3:Eu_x的合成及光谱性质

磷酸盐是一类十分稳定的晶体化合物 ,易形成 P— O键的多酸根聚合体[1 ] ,以直键或环状排列 ,它们能与稀土离子形成稳定的化合物。作为稀土发光材料的基质 ,具有吸收能力强、转换效率高、物理化学性质稳定、能承受大功率的电子束和高能射线等优点 ,在光致发光 [2 ] 、电致发光[3] 、阴极射线发光 [4 ] 和X射线发光 [5] 等方面获得了广泛的应用。近年来 ,关于稀土焦磷酸盐的合成已有不少的报道。常用的方法是高温固相法 [6 ] ,用此方法合成的样品虽然亮度高 ,但纯度较低 ,粒度不均匀 ,所以探索合成稀土焦磷酸盐的新方法十分有必要。本文采用液相法合成稀土焦磷酸盐 ,通过对产物的 X射线衍射图的分析来探索合成稀土焦磷酸盐的最佳酸度和最佳锻烧温度 ,并对产物的激发光谱和发射光谱作了分析 ,此方法具有纯度高、粒度小和工艺简单等特点。La4 - x(P2 O5) 3:Eux 的合成 :准确称取 1 0 .0 0 0 0 g La2 O3(99.99% )和 2 .0 0 0 0 g Eu2 O3(99.99% ) ,分别用浓 HNO3(优级纯 )溶解完全 ,加蒸馏水配制成 0 .1 mol/ L 的 La(N...

Synthesis and electroluminescent properties of a novel terbium complex

A new carboxylic acid ligand (o-amino-4-hexadecane benzoic acid, AHBA) and a corresponding terbium complex (Tb(AHB)(3)) were synthesized and characterized. A multilayer electroluminescent device with poly(N-vinylcarbazole) (PVK), 2-(4-biphenyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (PBD) and the terbium complex as emissive layer was fabricated: glass substrate/ITO/PPV/PVK:-To(AHB)(3):PBD/Alq(3)/Al. The photoluminescence (PL) and electroluminescence (EL) spectra were discussed. This EL cell exhibited characteristic emission of terbium ions with a maximum luminance of 35 cd/m(2) at 20 V. (C) 2000 Elsevier Science S.A. All rights reserved.

Green electroluminescence generated from the thin film based on a soluble lanthanide complex

Electroluminescent (EL) devices based on a soluble complex Tb(MDP)(3) [Tris-(monododecyl phthalate)Terbium] doped with poly (N-vinylcarbazole) (PVK), (2-(4-biphenyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole) (PBD) were fabricated. The device structures of ITO/PVK/PVK:PBD:Tb(MDp)(2)/Aiq(3)/Al and ITO/PVK:PBD:Tb(MDP)(3)/Alq(3)/Al were employed. The Tb(MDP), as emissive layer was spin-coated. The EL cell exhibited characteristic emission of terbium ion. (C) 2000 Elsevier Science S.A. All rights reserved.

Stimulated emission in the blue wavelength region from a copolymer containing PPV segment

The lasing properties of a soluble conjugated polymer, Poly[1,8-octanedioxy-2,6-dimethoxy-1,4-phenylene-1,2-ethenylene-1,2-phenylene-1,2-ethenylene-3,5-dimethoxy-1,4-phenylene] (CNMBC-Ph) in chloroform solution were investigated. The third harmonic radiation of a Nd:YAG laser was used as the pump light. The stimulated emission with a linewidth of 15 nm was observed in the blue wavelength region with the peak at 450 nm. The threshold pulse peak power was about 2.8 MW/cm(2). The energy conversion yield of the laser was estimated to be about 3.4%. The maximum peak power of the laser output pulse reached 40 kW. (C) 2000 Published by Elsevier Science S.A. All rights reserved.

Electroluminescence of a novel europium complex

Electroluminescent devices using a ternary europium complex Eu(DBM)(3)(hhpy)(2) (dibenzoylmethane, DBM; hexahydro pyridine, hhpy) as an emitting layer, poly(vinyl-carbazole) (PVK) as a hole-transporting material and tris-(8-hydroxyquinoline) aluminum (Alq(3)) as an electron-transporting material have been fabricated. When only using Eu(DBM)(3)(hhpy)(2) as the emitting layer, luminance of 2.52 cd/m(2) with pure Eu3+ EL emissions from devices is achieved. Introducing a hole transporting material PVK and an electron transporting material 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxidiazole (PBD) in the emitting layer, luminance of 100cd/m(2) is achieved, and the eletroluminescence efficiency is enhanced by about two orders of magnitude. (C) 2001 Elsevier Science B.V. All rights reserved.

A comparative study on the electroluminescence properties of some terbium beta-diketonate complexes

By comparing the phosphorescence spectra of Gd(acac)(3) (acac=acetylacetone), Gd(TFacac)3 (TFacac=1,1,1-trifluoroacetylacetone), the effects of fluorine replacement of hydrogen on the triplet state energy of the ligands were revealed. Fluorine can lower the triplet state energy of Hacac and make it more suitable for energy transfer towards the D-5(4) state of terbium. Organic electroluminescent devices (OELDs) with the corresponding trivalent terbium complexes as emissive layers were fabricated. Triple-layer-type devices with a structure of glass substrate/ITO (indium tin oxide)/PVK [poly(N-vinylcarbazole)]/PVK : Tb complex: PBD [2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole]/PBD/Al exhibit bright green luminescence upon applying a dc voltage. The luminance of a device with Tb(TFacac)(3)phen (1,10-phenanthroline) and Tb( TFacac) 3 as emissive layer is higher than that of the corresponding devices with Tb(acac)(3)(phen) and Tb(acac)(3) as emissive layers. The EL device with Tb(TFacac)(3)(phen) as emitter exhibits characteristic emission of Tb3+ ions with a maximum luminance of 58 cd m(-2) at 25 V.

Study of the conductivity and side chain mobility of a comb-like polymer electrolyte using the dynamic mechanical method

Using poly(styrene-co-maleic anhydride) as a backbone and poly(ethylene glycol) methyl ether (PEGME) with different molecular weights as side chains, three comb-like polymers and their Li salt complexes were synthesized. The dynamic mechanical properties and conductivities were investigated. Results showed that the polymer electrolytes possess two glass transitions: alpha -transition and beta -transition, and the temperature dependence of the ionic conductivity shows WLF (Williams-Landel-Ferry) behavior. Based on the time-temperature equivalence principle, a master curve was constructed by selecting T-beta as reference temperature. The values of the WLF parameters (C-1 and C-2) were obtained and were found to be almost independent of the length of the PEGME side chain and the content of Li salt. By reference to T-0 = 50 degreesC. the relation between log tau (c) and c was found to be linear. The master curves are displaced progressively to higher frequencies as the molecular weight of the side chain is increased. The relation between log tau (n) and the molecular weight of the side chain is also linear. (C) 2001 Elsevier Science B.V. All rights reserved.

Stimulated emission in blue wavelength region from a copolymer

A dye laser based on the soluble conjugated polymer, Poly[1,8-octanedioxy-2,6-dimethoxy-1,4-phenylene-1,2-ethenylene-1, 4-phenylene-1,2-ethenylene-3,5-dimethoxy-1,4-phenylene], has been fabricated. The laser was pumped by light pulses from the third harmonic radiation of an Nd:YAG laser. The lasing was observed in the blue wavelength region with the peak at 450 nm. The threshold energy is about 19 mu J. The energy conversion yield of the laser is about 3.4%. The maximum peak power of the laser output pulse arrives at about 20 kW.

Bright green organic electroluminescent devices based on a novel thermally stable terbium complex

A navel thermally stable terbium carboxylate complex, Tb(MTP)(3)(phen) (MTP=monotetradecyl phthalate, phen=1,10-phehanthroline), was synthesized and characterized. The device structure of glass substrate/indium-tin-oxide/poly(p-phenylenevinylene) (PPV)/poly (N-vinycarbazole) (PVK):Tb(MTP)(3)(phen): 1,3,4-oxadizole derivative (PBD)/tris(8-hydroxyquinoline) (Alq(3))/aluminum (Al) was employed to study the electroluminescent properties of Tb(MTP)(3)(phen). A green emission with extremely sharp spectral band of less than 10 nm at 544 nm peak wavelength was observed. A maximum luminance of 152 cd/m(2) and an external quantum efficiency of 0.017% were achieved at a drive voltage of 24 V. A possible mechanism of energy transfer based on the polymer doped with lanthanide organic complex was also proposed.

一种蓝色聚合物激光材料

聚合物作为一种有机发光材料，由于在平板显示和光电子器件中的良好应用前景而受到广泛研究［1～2］.近年来，一个重要进展是在聚合物中观测到了受激发射（简称Poly-mer激光）现象［3～6］.Polymer激光最早是在溶液中实现的［3～4］.作为一种新型…

The synthesis of a 1,1'-bi-2-naphthol-based bis(ether anhydride) and aromatic polyimides derived therefrom

2,2'-Bis(3,4-dicarboxyphenoxy)-1,1'-binaphthyl dianhydride was used as a new monomer with various aromatic diamines to obtain polyimides by the usual two-step method. The bis(ether anhydride) was prepared by a nucleophilic substitution of I,1'-bi-2-naphthol with N-phenyl-4-chlorophthalimide, N-methyl-4-nitrophthalimide or 4-nitrophthalonitrile in aprotic polar solvent, and subsequent hydrolysis of the resulting bis(ether imide)s or bis(ether dinitrile), and then dehydration of the corresponding tetracarboxylic acid to afford the dianhydride. Most of the obtained polyimides were soluble in chloroform, pyridine, DMF, etc. The polyimide prepared from p-phenylene diamine was partial crystalline, whereas the others showed amorphous patterns in a WAXD study. These polymers have glass transition temperatures between 255-294 degrees C and 5% weight loss temperatures in the range of 502-541 degrees C in nitrogen and 473-537 degrees C in air. (C) 1997 Elsevier Science Ltd.