Effect of concentration on the photoluminescence properties of Sm3+ and Dy3+: cadmium lithium boro tellurite glasses

Rare-earth (Sm3+ or Dy3+) ions doped cadmium lithium boro tellurite glasses have been prepared by melt quenching method for their spectral studies. From X-ray diffraction (XRD) patterns the glass amorphous nature has been confirmed. Vis-NIR absorption, excitation and emission spectra of these glasses have been analyzed systematically and also rare earth ion concentration is optimised Sm3+: CLiBT glasses have shown strong orange-reddish emission at 598 nm (4G5/2-->6H7/2) with an excitation wavelength lambda(exci) = 401 nm and Dy3+: CLiBT glasses have shown strong yellow emission at 574 nm (6F9/2-->6H13/2) with lambda(exci) = 451 nm.     

Emission Properties of Yb3+/Er3+ Doped TeO2-WO3-ZnO Glasses for Broadband Optical Amplifiers

The YbS /Er3 doped TeO2-WO3-ZnO glasses were prepared. The absorption spectra, emission spectra and fluorescence lifetime of Era at 1.5μm, excited by 970 nm were measured. The influence of Er2Oa, Yb2Oa and Ohcontents on emission properties of Era at 1.5 μm was investigated. The optimum doping concentrations for Era and Yba is around 3.34× 1020 ions/cma and 6.63×1020 ions/cma, respectively. The peak emission cross section is 0.83～0.87 pm2. With the increasing concentration of Yba , the FWHM of Era emission at 1.5 μm in the glass increases from 77 nm to 83 nm. The results show that Yba /Era doped meO2-Woa-ZnO glasses are promising candidate for Era -doped broadband optical amplifier.     

P2O3-B2O3-Al2O3-SrO-BaO玻璃中Yb3+非辐射能量转移下Er3+离子的增强发射

本文研究了共掺Er3 +/Yb3 +P2 O3 -B2 O3 -Al2 O3 -SrO -BaO玻璃的能量转移过程。实验中制备了高掺杂Yb3 +离子的双掺Er3 +/Yb3 +的磷酸盐玻璃样品。在Er3 +/Yb3 +掺杂比率 >1 :1 8(mol% )时 ,观测到了基于Yb3 +离子至Er3 +离子能量转移下Er3 +( 4 I13 / 2 →4I15 / 2 )的增强发射和Yb3 +( 2 F7/ 2 →2 F5 / 2 )发射的减弱 ,当Yb3 +离子掺杂浓度超过 2 .1× 1 0 2 1ions/cm3 时 (Er3 +/Yb3 +≤ 1 :1 8,mol% ) ,由于Yb3 +离子的自淬灭效应 ,Er3 +离子的发射强度降低。实验中得到了Yb3 +离子的最佳掺杂浓度为1 .74× 1 0 2 1ions/cm3     

掺镝的氟锆酸盐玻璃的光谱

测量了氟锆酸盐玻璃中Dy3+离子的吸收光谱和荧光光谱,得到了Dy3+离子的J-O参量Ωt,Ω2=3.29×10 20cm2,Ω4=1.56×10 20cm2,Ω6=2.48×10 20cm2.计算了氟锆酸盐玻璃中Dy3+离子的发射特性,Dy3+离子1.3μm发射的6F11/2(6H9/2)→6H15/2跃迁的发射截面σe=0.62×10-20cm2.研究了Dy3+离子浓度对其荧光强度的影响,当Dy3+离子掺杂浓度(摩尔分数)超过1.5%时,发生了浓度淬灭效应.     

Synthesis and luminescence properties of Sr2SiO4: Eu3+, Dy3+ phosphors by the sol-gel method

The Sr2SiO4:Eu3+, Dy3+ phosphors for white light emitting diodes (LEDs) were synthesized by the sol-gel method. The microstructure and luminescent properties of the obtained Sr2SiO4:Eu3+, Dy3+ particles were well characterized. The results demonstrate that the Sr2SiO4:Eu3+, Dy3+ particles, which have spherical morphology, emitted an intensive white light emission under excitation at 386 nm. The phosphors show three emission peaks: the blue emission at 486 nm corresponding to the 4F(9/2)-6H(15/2) transition of Dy3+, the yellow emission at 575 nm corresponding to the 4F(9/2)-6H(13/2) transition of Dy3+, and the red emission at 615 nm corresponding to the 5D0-7F2 transition of Eu3+. At the same time, the effect of Eu3+ concentration on the emission intensities of Sr2SiO4:Eu3+, Dy3+ was investigated in detail. The phosphors used for white LEDs were obtained by combining near ultraviolet (NUV) light (386 nm) with Sr2SiO4:0.04Dy3+, 0.01Eu3+ phosphors with the characteristic of Commission Internationale de l'Eclairage (CIE) chromaticity coordinate (x, y) of (0.33, 0.34), and color temperature Tc of 5,603 K. In addition, the effect of the charge compensators (Li+, Na+, and K+ ions) on the photoluminescence (PL) emission intensities were studied.     

Sm3+/Ce3+/Tb3+共掺CaO-B2O3-SiO2发光玻璃的制备及发光性能研究

采用高温熔融法制备了Sm3+/Ce3+/Tb3+共掺杂的CaO-B2O3-SiO2发光玻璃材料,并用荧光分光光度计和CIE色度坐标对其发光性能进行了研究。发射光谱表明,在374nm激发下,Sm3+/Ce3+/Tb3+共掺杂CaO-B2O3-SiO2发光玻璃的发射光谱中同时观测到了红橙光、蓝光和绿光的发射带,这些发射带的混合实现了白光发射。此外,在Sm2O3和Tb4O7含量不变的情况下,随着CeO2含量的减小,Sm3+/Ce3+/Tb3+共掺杂发光玻璃的发光颜色在白光区逐渐由蓝光区附近过渡到黄光区附近。     

ZrO2和ZrO2:Dy3+纳米晶发光特性

采用液相沉淀法制备了不同掺杂浓度和尺寸的ZrO2和ZrO2:Dy纳米晶,研究了其发光特性.结果表明在纳米ZrO₂中,存在着宽带激发和发射,起源为电子在价带和导带之间的跃迁.在Dy³⁺掺杂的样品中,随着颗粒尺寸的长大,其发光增强.并且共掺杂Li⁺的样品发光强度被极大地提高.随着Dy³⁺浓度的变化,黄发射和蓝发射的强度比(Y/B)发生改变,且浓度猝灭是通过近邻激活剂间的交换作用进行的.     

Yb3+、Er3+和Eu3+共掺杂TiO2纳米带的制备与表征

通过离子交换和水热两步合成过程简单制备了Yb3+、Er3+和Eu3+共掺杂锐钛矿型TiO2纳米带。该3种离子共掺杂未导致TiO2结构和形貌发生变化。光学特性测试结果表明,由于稀土离子掺杂浓度低,Eu3+掺杂未改变由Yb3+和Er3+产生的上转换发射峰位,但可观察到因上转换发光激发的Eu3+荧光发射峰;Eu3+荧光光谱也未受到Yb3+和Er3+掺杂的影响。通过对掺杂样品上转换发光机理的考察证实,上转换发光过程是双光子过程,但TiO2和Eu3+掺杂对此发光过程有明显影响。     

掺铒铋酸盐玻璃光谱性质的混合形成体效应

测得了Er3+离子在铋酸盐玻璃系列(50～75)Bi2O3-(20～45)B2O3-5Na2O,70Bi2O3-(17～25)B2O3-xZrF4-5Na2O,70Bi2O3-(0～25)B2O3-(0～25)SiO2-5Na2O中的吸收光谱、荧光光谱及4I13/2能级荧光寿命.提出并研究了Er3+离子光谱性质的混合形成体效应,结果表明Er3+离子在铋酸盐玻璃中通过混合形成体效应可以获得较大的有效线宽(△λeff＝62～80nm)、较高的受激发射截面(σe＝0.76～0.84×10-20cm2)、较宽的荧光半高宽(FWHM＝55～80nm)以及较长的荧光寿命(τm＝1.6～4.3ms),说明掺Er3+铋酸盐玻璃是光纤放大器实现宽带和高增益放大较为理想的基质材料.     

Dy3+掺杂CaWO4荧光粉体的制备及发光性能

采用固相陶瓷方法制备了Dy3+掺杂的CaWO4∶Dyx3+荧光粉体。采用XRD、SEM和FT-IR对制备粉体的微观结构进行了表征;采用荧光分析法研究了制备的荧光体的室温光致发光性能;探讨了掺杂剂Dy3+浓度对CaWO4∶Dyx3+荧光粉体的微结构和光致发光性能的影响。结果表明,制备的CaWO4∶Dyx3+荧光粉体为白钨矿结构,Dy3+的掺入会抑制CaWO4∶Dy3x+晶粒的生长。当Dy3+的掺入量为1%(摩尔分数)时,其在480nm(蓝)和575nm(黄)的发射强度达到最大;随着Dy3+浓度的增加,其特征发射峰(480nm和575nm)强度反而逐渐下降。     

高声子能量氧化物对掺铒碲酸盐玻璃光谱性质的影响

在研制的Er3+/Ce3+共掺低声子能量碲酸盐玻璃(TeO2-Bi2O3-TiO2)中,分别引入高声子能量WO3、SiO2和B2O3氧化物组分,测试了玻璃样品400~1700 nm范围内的吸收光谱、1.53μm波段荧光谱、Er3+离子荧光寿命和拉曼光谱,结合McCumber理论计算了Er3+离子光谱参数.结果表明:高声子能量氧化物组分的引入,能使声子参与的Er3+/Ce3+离子间能量传递过程变得更为有效,增加了Er3+离子亚稳态能级4I13/2上粒子数积累,从而增强1.53μm波段荧光发射.另外,高声子能量氧化物组分的引入还可以增加荧光半高宽(FWHM)和带宽品质因子(σe×FWHM).研究结果对于获取具有优异光谱特性的掺Er3+光纤放大器(EDFA)的玻璃基质具有实际意义.     

Fabrication and up-conversion luminescence of Er3+:Y2O3 nanoparticles

Y2O3 nanoparticles doped with different concentrations of Er3+ were prepared by the co-precipitation method. X-ray diffraction and transmission electron microscopy results show that Er3+ dissolves completely in the Y2O3 cubic phase. The Er3+:Y2O3 nanoparticles are homogeneous in size and nearly spherical, and the average diameter of the particles after being calcined at 1,000 degrees C for 2 h is in the range of 40-60 nm. When Er3+:Y2O3 nanoparticles are excited under a 980 nm diode laser, there are two main emission bands: green emission centered at 562 nm corresponding to the 4S3/2/2H11/2 --> 4115/2 radiative transitions and red emission centered at 660 nm corresponding to the 4F9/2 --> 4I15/2 radiative transitions. By changing the doping concentration of Er3+ ions, the up-conversion luminescence can be gradually tuned from green to red.     

Microstructure and environment dependence of 2H11/2 --> 4I15/2 upconversion emission in YVO4:Er3+, Yb3+ nanocrystals

Upconversion emission of different nanocrystalline YVO4:Er3+, Yb3+ synthesized by a hydrothermal process at low temperature was studied under 980 nm excitation where green [(2H11/2, 4S3/2) --> 4I15/2] and red (4F9/2 --> 4I15/2) emissions demonstrate sensitivity to the local environments of Er3+. Small particle size, high Yb3+ concentration, or high temperature favors the emission of the 2H11/2 --> 4I15/2 transition. Both XRD patterns and Raman spectra have confirmed that crystal lattice distortion of YVO4:Er3+, Yb3+ nanocrystals is more serious when the nanoparticle size is decreasing or Yb3+ concentration is increasing. This distortion is thought to play a key role in the observed spectral properties, which might lead to a new route to improve the monochromatic upconversion emission efficiency in these nanocrystals.     

网络修饰体对铕-镝共掺铝硼硅酸盐玻璃白光发光影响

采用高温熔融的方法,在空气中制备了一系列添加不同网络修饰体氧化物的Eu2 O3和Dy2 O3共掺杂铝硼硅酸盐玻璃,并测试了其在紫外光激发下的发光性能.从发射谱中可以看到归属于Eu2+、Eu3+和Dy3+离子能级跃迁的蓝、绿、黄、红等多色发射带共存.这些发射带之间的相对强度会随着网络修饰体氧化物的改变而变化,从而导致发光色度的变化.加入适当的网络修饰体氧化物可得到合适的白光发射.此外,在空气中制备过程中发生了Eu3+→Eu3+的还原反应.用Li2O取代ZnO时,该还原反应程度降低,而用CaO取代BaO时该还原反应程度增强,其机制与玻璃组分的光碱度有关.     

掺稀土离子玻璃的光放大效应

光放大材料是光纤放大器的主要组成部分，它决定光纤放大器的光放大功率。本文介绍了掺稀土离子如Er^3 、Nd^3 、Pr^3 及Dy^3 等玻璃的光放大原理以及影响光放大的各种因素。稀土离子本身存在的多种发射跃迁、无辐射跃迁，稀土离子间相互作用以及玻璃基质都影响稀土离子的光放大跃迁效率。上述分析对掺稀土离子玻璃的光放大材料性能的改进和新材料的设计可提供有益的指导。     

White luminescence of Dy3+ ions doped 12CaO 7Al2O3 nanopowders under UV light excitation

12CaO 7Al2O3:Dy3+ nanopowders were successfully synthesized by the chemical co-precipitation method. X-ray diffraction result shows that the single 12CaO 7Al2O3 phase is formed with Dy3+ ions to replace the Ca2+ ions in the host of 12CaO 7Al2O3. The yellow and blue emissions, attributed to the forced electric dipole transition of 4F(9/2) --> 6H(13/2) centered at 571 nm and the magnetic dipole transition of 4F(9/2) --> 6H(15/2) centered at 480 nm, respectively, were observed. The integrated intensity ratios of yellow to blue increase from 1.63 to 1.70 with Dy3+ concentration increasing from 0.8 to 2.0% for the as-prepared 12CaO 7Al2O3:xDy3+ phosphor. The significantly enhanced emission intensities of 12CaO 7Al2O3:1.0% Dy3+ phosphor annealed at 900 degrees C for 2 hours in vacuum ambient could be ascribed to the decrease of OH(-) groups and the change of the surface topography. The thermal stability and the Commission International de l'Eclairage coordinates were also investigated. All the photoluminescence characteristics indicate that Dy3+ ions doped 12CaO 7Al2O3 may be a good candidate for the solid state lighting phosphor as well as white light-emitting diodes.     

Er3+/Yb3+掺杂NaGd(WO4)2粉体的制备与发光性能

采用水热法成功制备了Er~(3+)/Yb~(3+)双掺杂的NaGd(WO_4)_2纳米粉体,研究了不同络合剂、水热温度对样品形貌和结构的影响。测量了不同Er~(3+)掺杂浓度样品的可见上转换和近红外发射光谱。结果表明:在980nm LD激发下,可观测到样品强烈的绿色上转换发光,对应Er~(3+)的~2H_(11/2)→~4I_(15/2)(530nm)和~4S_(3/2)→~4I_(15/2)(552nm)跃迁,以及较弱的红色上转换和近红外发光,分别对应Er~(3+)的~4F_(9/2)→4I15/2(656nm)和~4I_(13/2)→~4I_(15/2)(1 532nm)跃迁。且随着Er~(3+)掺杂浓度的增加,样品的上转换红绿光和1.54μm附近的近红外光均呈现出先增大后减小的趋势。样品的激发和发射光谱显示,在378nm处的激发峰最强,对应Er~(3+)的~4I_(15/2)→~4 G_(11/2)能级跃迁,最强发射峰位于552nm。根据泵浦功率与发光强度的关系可以得出,红光和绿光的发射主要为双光子吸收过程,但红光还包含了一定的单光子吸收成分。     

White up-conversion luminescent property in Re3+:Gd3Ga5O12 nanocrystals

Rare-earth ions doped Gd3Ga5O12 nanocrystals have been prepared by a propellant combustion synthesis method and their up-conversion properties were systematically investigated in this paper. XRD, SEM, TEM, and up-conversion emission spectra were used to characterize the synthesized nanocrystals. Energy transfer from Yb3+ to Er3+ and Tm3+ can occur simultaneously in the as-synthesized Gd3Ga5O12 nanocrystals. The up-conversion mechanisms and relevant energy transfer processes are discussed. A white light generation was observed when the Yb3+, Er3+ and Tm3+ were directly incorporated in the Gd3Ga5O12 lattice. And its calculated color coordinates is (0.35, 0.41) under the excitation at 974.5 nm. The bright white luminescent nanocrystals may have potential application in the field of lighting, displays and photonics.     

Photoluminescence and Optical Transition Dynamics of Er3+ Ions in Porous Si

1.IntroductionThereisagrowinginterestinrare-earthsd0pedSionaccount0fitspotentialapplicati0nsinSi-basedoptoelectronicdevicesandsystems.InparticularEr-dopedSihasattractedmuchattentionbecauseEri0ninitstriva1entstate(Er'+)showssharpphotolumi-nescence(PL)around1.54pm,oneofthestandardwavelengthsinsilicafiber-basedopticalc0mmunica-tiontechnology-Alth0ughal0tofpapersonthed0p-.ingandPLofEr3+havebeenpublished{1],thereisalack0fsufficientunderstanding0ftheluminescencemechanismatpresent.Inthecase0fEr-…     

Tunable luminescence of Dy3+ single-doped and Dy3+/Tm3+ co-doped tungsten borate glasses

RE³⁺ (RE³⁺ = Tm³⁺, Dy³⁺) ion single and co-doped tungsten borate glasses for white light emitting diodes (LEDs) were prepared by melt quenching method. Emission and excitation spectra of the glasses were measured. The color of luminescence can be tuned by changing the composition of glass matrix or the concentrations of Tm³⁺ and Dy³⁺ ions. White light emission can be achieved from 0.5Dy³⁺ single-doped 15WO₃–25La₂O₃–60B₂O₃ and 0.4Tm³⁺/1.5Dy³⁺ co-doped 50WO₃–25La₂O₃–25B₂O₃ glasses. In addition, energy transfers between Tm³⁺ and Dy³⁺ were also analyzed. The Dy³⁺/Tm³⁺ co-doped tungsten borate glasses may be potential candidates for white LED application.