用同步辐射研究掺Tb^(3+)氟化物K_2GdF_5的光谱和Gd^(3+)-Tb^(3+)能量传递

对比了不同激发波长下水热法合成的K2GdF5∶Tb3+(摩尔分数0.5%)单晶材料的光致发光谱线;监测了5D3→7F6和5D4→7F5的激发谱,给出了几组窄带吸收和3个宽带吸收;分析表明窄带发射为Gd3+的8S7/2→6FJ、8S7/2→6 GJ、8 S7/2→6 DJ、8 S7/2→6 IJ的跃迁,宽带发射为Gd3+的基态7 F6到4f7(8 S)5d组态中的低自旋态的跃迁;此外,还对Gd3+→Tb3+的能量传递和Tb3+之间的交叉弛豫进行了初步分析。

银颗粒对Lu_2O_3:Eu薄膜光学性质的影响(英文)

采用溶胶凝胶和提拉法制备了含有银颗粒的Lu2O3:Eu薄膜,利用X射线衍射,吸收光谱,光致发光光谱(PL)及荧光衰减光谱对其进行了表征,结果表明:所得材料在800℃下结晶完好,在发射光谱中观察到了银颗粒导致的Eu3+的发光增强效应,讨论了银颗粒对Lu2O3:Eu薄膜发光性质的影响.

Luminescence Properties of Tb^(3+)-Doped LuAG Films Prepared by Pechini Sol-Gel Method

Lu3Al5O12（LuAG） thin films with different Tb^3＋ concentration were prepared on carefully cleaned （111 ） silicon wafer by a Peehini process and dip-coating technique. Heat treatment was performed in the temperature range from 800 to 1100 ℃. The crystal structure was analyzed by XRD. The results show that LuAG film starts to crystallize at about 900 ℃, and the particle size increases with the sintering temperature. Excitation and emission spectra of Tb^3＋ doped LuAG films were measured. The effects of heat-treatment temperature and doping concentration of Th3 ＋ on the luminescent properties were also investigated. For a comparison study, Th^3＋-doped LuAG powders were also prepared by the same sol-gel method.

A white long-lasting phosphor Y_2O_2S:Tb^(3+), Sm^(3+): an improvement of Y_2O_2S:Tb^(3+)

As an improvement of reported Y2O2S：Tb^3＋, a white-light long-lasting phosphor： Y2O2S：Tb^3＋, Sm^3＋ was prepared by the solid-state reaction. The photo-luminescence spectra showed that the position and shape of Tb^3＋ and Sm^3＋ emissions under UV excitation were similar in this host, which ensured a stable white emission color （daylight standard of IEC） under different excitations. The decay curves of co-doped samples indicated that the decay times of emissions of the two ions were close. The thermo-luminescence measurement suggested that the traps created by the doped Sm^3＋ ions were helpful to postpone the white afterglow of co-doped samples. Therefore, the function of co-doped Sm^3＋ ions was confirmed as improving the white emission colors of samples and acting as new trap centers.

Synthesis and Luminescence Properties of Red Phosphors:Mn^(2+) Doped MgSiO_3 and Mg_2SiO_4 Prepared by Sol-Gel Method

Sol-gel method was utilized to synthesize two different series of red silicate phosphors : MgSiO3 and Mg2SiO4 powder samples doped with Mn2+, conducted the investigation of red long-lasting phosphor: MgSiO3 : Eu2 + , Dy3+, Mn2+ . TGA curves of the gel precursor for two series depicted that the loss of residual organic groups and NO3 groups occurs below 450℃. According to the XRD patterns, the major diffraction peaks of the MgSiO3 and Mg2SiO4 series are consistent with a proto-enstatite structure (JCPDS No.11-0273) and a forsterite structure (JCPDS No.85-1364) respectively. With the excitation at 415 nm, the red emission band of Mn2+ ions is peaked at 661 nm for MgSiO3:1%(atom fraction) Mn2+ or 644 nm for MgiSiO4: 1 %(atom fraction) Mn2+ . Compared with Mg2SiO4:Mn2+ samples, MgSiO3:Mn2+ samples exhibit higher luminescence intensity and higher quenching concentration. In addition, the two series co-doped with Eu2+ , Dy3+ , Mn2+ were also prepared. Photo-luminescence and afterglow properties of the two co-doped series were analyzed, which show that MgSiO3: Eu2 + , Dy3+ , Mn2+ is more suitable for a red long-lasting phosphor.

Luminescent properties of β-Lu_2Si_2O_7:RE^(3+)(RE=Ce, Tb) nanoparticles by sol-gel method

Nanoscale RE^3＋ （RE=Ce, Tb） doped and codoped lutetium pyrosilicate Lu2Si2O7（LPS） phosphors were prepared by using the sol-gel method. Heat treatment was performed in the temperature range from 900 to 1100 ℃. The crystal structure was analyzed by X-ray diffraction （XRD）. The results showed that the β-type structure of LPS was obtained at 1100 ℃. The excitation spectra in the UV and VUV ranges and the emission spectra of the samples were measured at room temperature, and their luminescent properties were studied. The energy transfer from Ce^3＋ to Tb^3＋ in the codoped samples were observed and discussed.

Study of cerium ion in (Y_(0.95)La_(0.05))_2O_3:Ce

(Y0.95La0.05)2O3: Ce3+ nano-powder was synthesized by co-precipitation method and sintered at 800 and 900 oC. All the samples were cubic phase characterized by X-ray diffraction (XRD) analysis. The samples sintered at the lower temperature exhibited luminescence. According to the distinguishable structure of Ce 3d peaks and the shift of O 1s lines in the X-ray photoelectron spectroscopy (XPS), luminescence was further confirmed to originate from Ce3+ ions. Effects of introducing La3+ into Y2O3 were discusse...