Preparation and Upeonversion Lumineseenee ofNanoerystailine Gd2O3： Er^3＋, Yb^3＋

Nanocrystalline Gd1.77Yb0.2Er0.03O3 samples were prepared by combustion and precipitation methods. Structures and upconversion luminescence properties of samples were studied. The results of XRD show that all samples are cubic structure, the average crystallite size could be calculated as 23 nm and 39 nm, respectively. The lattice constants were obtained. The FT-IR spectra were measured to investigate the vibrational feature of the samples. Upconversion luminescence spectra of samples under 980 nm laser excitation were investigated. The strong red emission of samples were observed, and attributed to 4F9/2→4I152 transitions of Er^3＋ ions, the emission intensity for sample synthesized by precipitation method is stronger compared to that of combustion method. The possible upconversion luminescence mechanisms in nanocrystalline Gd1.77Yb0.2Er0.03O3 were discussed.     

Synthesis and luminescence properties of Eu3＋, Sm3＋ doped （YxGd1-x）2O3： Si4＋, Mg2＋ long-lasting phosphor

A novel red long-lasting phosphor,(Y1-xGdx)2O3:Eu3+,Sm3+,Si4+,Mg2+,was synthesized by the co-precipitation method using oxalate precipitation as the precursor.X-ray diffraction(XRD),scanning electronic microscopy(SEM),integrated thermal analyzer(TG),and photoluminescence spectra(PL) as well as the ST-900PM weak light photometer were used to study the synthesis conditions,morphology,luminescence properties,and the decay time of the phosphor.The XRD results show that the products synthesized at 1400°C for 4 h...     

上转换材料LiLa（MoO4）2：Yb^3＋，Er^3＋（Tm^3＋）的制备及其光谱性质测定

采用溶胶-凝胶法制备了上转换材料LiLa（MoO4）2：Yb^3＋,Er^3＋（Tm^3＋）,并对其进行了X射线衍射分析以及荧光光谱测定．在980nm红外激光器激发下,LiLa（MoO4）2：Yb^3＋,Er^3＋发出波长为530nm和550nm的绿色可见光,而LiLa（MoO4）2：Yb^3＋,Tm^3＋发出波长为475nm的蓝色可见光．对Yb^3＋／Er^3＋和Yb^3＋／Tm^3＋双掺体系的上转换发光机理进行了探讨,其中Er^3＋发出绿色上转换光的过程为双光子过程,而Tm^3＋发出蓝色上转换光的过程为三光子过程。     

反应pH值对水热法合成PbF2：Er^3＋,Yb^3＋荧光粉性能的影响

本文以PbF2为基质,Er^3＋为激活剂,Yb^3＋为敏化剂,采用水热法,通过严格控制pH值,成功制备了PbF2：Er^3＋,Yb^3＋上转换发光材料。采用X射线衍射仪和荧光分光光度计分析了样品的结构和发光性能,结果表明,当pH值=4时,产物为立方晶系纯相PbF2,上转换发光性能最佳。在980nm光激发下,样品发射源于Er^3＋离子^2H11/2→^4I15/2、^4S3/2→^4I15/2能级跃迁的绿光（520-570nm）和4F9/2→4I15/2能级跃迁的红光（650-680nm）。     

YF3：Yb^3＋,Er^3＋纳米上转换发光材料的制备与表征

以Y2O3、Er2O3、Yb2O3和不同氟源（NaBF4、NaF和NH4F）为原料,利用PEG-2000辅助的水热法合成出不同形貌的YF3：Yb^3＋,Er^3＋纳米上转换发光材料,考察了不同反应时间和不同氟源对样品形貌和晶相的影响。SEM照片表明：不同的反应时间和不同氟源对YF3：Yb^3＋,Er^3＋纳米粒子的形貌和尺寸影响较大。XRD分析表明：加NaBF4和NaF所得的样品均为正交晶系的YF3,加NH4F所得样品为立方晶系的YF3。上转换发射光谱表明：不同氟源和在不同温度下所得样品的发射光谱均可以观察到在522nm到545nm之间的绿光发射带和位于653nm附近的红光发射峰,分别对应于Er^3＋的2H11/2、4S3/2→4^I15/2跃迁和4H9/2→4^I15/2的跃迁。不同氟源所得样品的红绿光强度有所不同,随着反应时间的增加,发光强度有所增强。     

Upeonversion Luminescence of Er3＋, Tin3＋ and Yb3＋ Co-doped Gd3Ga5O12 Nanocrystals

A series of Er3+,Tm3+ and Yb3+ doped Gd3Ga5O12 nanocrystals were prepared by a combustion method.The X-ray diffraction(XRD),field emission scanning electron microscope(FESEM)and upconversion(UC)emission spectra were used to characterize the samples.The results of XRD indicate that Gd3Ga5O12:Er3+,Tm3+,Yb3+ nanocrystals with cubic phase can be obtained.Under the excitation of a 980 nm laser,the different rare earth ions doped Gd3Ga5O12 nanocrystals show upconversion luminescence involving the green emission attributed to the 2H11/2→4I15/2,4S3/2→4I15/2 transitions of Er3+ ions,respectively,the red emissions assigned to the 4F9/2→4I15/2 transitions of Er3+ ions and the 1G4→3F4 as well as 3F2,3→3H6 transitions of Tm3+ ions,respectively,the blue emission attributed to 1G4→3H6 transitions of Tm3+ions,and the near-infrared assigned to the 3H4→3H6 transitions of Tm3+ ions.The CIE coordinates for the samples are calculated.The dependence of their upconversion luminescence properties on Yb3+ ion concentration is investigated.     

纳米NaYF4：Nd^3＋、Dy^3＋材料的上转换光学特性

制备了Nd^3＋和Dy^3＋掺杂立方相NaYF4上转换发光纳米晶体,用XRD、荧光光谱等测量手段对纳米颗粒的结构和发光性能进行表征,探讨Nd3’和Dy¨的掺杂比例对上转换发光的影响．利用776nm红外光激发样品,NaYF4：Nd^3＋,Dy^3＋实现蓝、绿上转换发光,出现Dy^3＋特征峰：479nm、574nln上转换发射峰．探讨基质NaYF4中Nd^3＋对Dy^3＋的敏化作用及上转换机制．     

Upeonversion Emission and Paramagnctism of Colloid Ba2ErF7 and Ba2ErFT：Yb3＋ Nanoerystals Synthesized with Solvothermal Method

Ultrasmall near-monodisperse Ba2ErF7 nanocrystals with average crystal size 9.6 nm were synthesized with solvothermal method. The X-ray diffraction （XRD） and transmission electron microscopy （TEM） assays reveal that the as-synthesized Ba2ErF7 nanocrystals are of the cubic structure with the cell parameter of 5.943 A, instead of the reported orthorhombic and tetragonal structure. Two emission bands originated from 2Hwj4H3/2 → 4F5/2 and 4F9/2 ----＋ 4115,2 of Er3＋ can be observed under a 980 nm laser excitation. The magnetic mass susceptibility of the as-synthesized BazErF7 nanocrystals reaches 4.293 × 10-5 emu g-1 Oe-1.     

燃烧法制备NaYF_4:Er~(3+),Yb~(3+)纳米发光粉

采用低温燃烧法制备了NaYF4:Er3+,Yb3+上转换纳米发光粉。确定最佳工艺参数为:尿素用量为200%stio,烧结温度为600℃,反应时间为8min。通过X射线衍射和透射电镜分析了晶粒尺寸和粉体粒径,粒径为30～35nm。结构为六方晶相。NaYF4:Er3+,Yb3+样品对980nm附近的波长具有上转换发光效应,上转换发射光谱5个发光峰分别为380、408、522、540和658nm。拟合材料发光强度与泵浦功率之间的关系说明,380、408nm紫光发射属于三光子过程,526、540和652nm发射均属于双光子过程。     

微乳液水热法制备NaYF4:Yb,Er上转换发光材料

采用微乳液水热法制备了NaYF4:Yb3+,Er3+的上转换纳米氟化物,粉末X-射线衍射(XRD)图显示:反应时间在48h以内,NaYF4:Yb3+,Er3+纳米粒子产物并非NaYF4的单一相。水热时间延长到72h时,所得产物与PDF#28-1192相吻合,表明产物转变为单一的β-NaYF4。扫描电镜分析结果表明,NaYF4:Yb3+,Er3+纳米粒子随反应时间增加由立方相过渡为六方相,粒径大约在150-160nm。近红外荧光和上转换荧光光谱研究发现,下转换光谱最强发射峰位于1540 nm(对应于4I13/2—4I15/2);Yb3+(c/mol):Er3+(c/mol)=3:1时上转换发射中心分别在523nm、538nm和655nm(分别对应2H11/2→4I15/2、4S3/2→4I15/2和4F9/2→4I15/2跃迁)。通过分析上转换发光机理,发现无论绿光发射还是红光发射均为双光子过程。     

Er~(3+)、Y~(3+)、Yb~(3+)离子共掺杂的氧化铝发光材料的制备及其表征

随着光通信的发展,人们对于光通信所用的放大器,以及放大器所用的发光材料的要求越来越高,越来越苛刻.在光通信系统中,由于掺稀土光纤放大器的结构使得它不可能被集成,人们开始考虑研制平面掺铒光波导放大器(EDWA),即利用光波导掺入的稀土铒离子在抽运光作用下的受激辐射实现的.光通信器件的小型化集成化是发展的趋势.本文通过Y~(3+),Yb~(3+),与Er~(3+)共掺Al2O3粉末,试图提高Er~(3+)在基体中的分散度和均匀度,降低掺Er~(3+)材料中的光子猝灭中心(—OH)浓度,研究不同浓度Yb~(3+)共掺对材料微结构的调制情况,以及对Al2O3发光特性的影响,以期获得性能优良的Al2O3发光材料.     

Preparation and Upconversion Luminescence of Nanocrystalline Gd2O3:Er3+,Yb3+

Nanocrystalline Gd1.77 Yb0.2Er0.03O3 samples were prepared by combustion and precipitation methods.Structures and upconversion luminescence properties of samples were studied.The results of XRD show that all samples are cubic structure,the average crystallite size could be calculated as 23 nm and 39 nm.respectively.The lattice constants were obtained.The FT-IR spectra were measured to investigate the vibrational feature of the samples.Upconversion luminescence spectra of samples under 980 nm laser excitation were investigated.The strong red emission of samples were observed,and attributed to 4F9/2→4I15/2 transitions of Er3+ ions,the emission intensity for sample synthesized by precipitation method is stronger compared to that of combustion method. The possible upconversion luminescence mechanisms in nanocrystalline Gd1.77Yb0.2Er0.03O3were discussed.     

ZrF2－SiO2基质中Er^3＋在蓝／绿波段的上转换发光

为了进一步探讨稀土Er^3 掺杂材料在蓝／绿可见波段和紫外波段的上转换发光机制，制备了掺杂Er^3 的ZrF2-SiO2材料，测量了样品的吸收谱和在980nmLD激发下的上转换荧光发射谱，研究了上转换发光强度与激光泵浦功率的对数关系．分析了稀土Er^3 中4f电子跃迁的特征．证实了在980nmLD的激发下，ZrF2-SiO2：Er^3 在404nm、445nm和525nm、548nm附近的蓝／绿可见波段上转换发光过程是激发态吸收(ESA)，得到了^2H9／2→^4I15/2,^4F5/2→^4I15/2蓝光三光子过程和^4S3/2→^4I15/2,^2H11/2→^4I15/2绿光双光子过程上转换发光机制。     

Yb~(3+)/Ho~(3+)掺杂纳米氟磷灰石的制备及发光性质研究

利用水热法成功制备了Yb~(3+)/Ho~(3+)掺杂氟磷灰石(FA:Yb~(3+)/Ho~(3+))纳米材料,通过改变稀土离子Yb~(3+)的掺杂比例有效提高了纳米材料的上转换发光强度。利用透射电子显微镜(TEM)、X射线衍射仪(XRD)、傅里叶红外光谱仪(FTIR)、荧光光谱仪等表征手段对Yb~(3+)/Ho~(3+)掺杂纳米氟磷灰石的形貌、结晶程度和物相组成、发光性质进行了研究。结果表明,Yb~(3+)/Ho~(3+)掺杂氟磷灰石纳米材料呈棒状并具有六方相结构。通过对稀土离子Yb~(3+)的掺杂比例进行调节,使得材料的上转换发光效率有了明显的增强,Yb~(3+)的掺杂含量为60%时发光最强。因此,这类具有较好上转换发光性能的FA:Yb~(3+)/Ho~(3+)纳米材料可为细胞标记和成像提供良好的条件,有望促进其在生物医药领域中的广泛应用。     

波导制备用铒镱掺杂磷酸盐玻璃的光学光谱参数

制备了一种具有优异化学稳定性的碱性铝磷酸盐玻璃,将该玻璃样品浸入390℃下的KNO_3熔盐中离子交换2h后得到了平面波导。有效扩散系数为0.11μm~2/min,说明该玻璃实现了高效的离子交换。通过光谱分析可得,~4I_(13/2)→~4I_(15/2)能级跃迁的半高宽和最大发射截面分别为30nm和6.80×10~(-21)cm~2。结果表明,当~4I_(13/2)能级上Er~(3+)的比例达到80%时,计算得到的理论增益可以达到2.97dB/cm。     

纳米发光粉体LaPO_4:Sm~(3+)的制备及表征

以乙二醇为溶剂制备了纳米LaPO4:Sm3+;通过TEM与普通共沉淀法制备的样品形貌对比,讨论了制备方法对样品形貌的影响;对LaPO4:Sm3+发光性能进行了探讨。采用以乙二醇为溶剂法制备纳米LaPO4:Sm3+,与共沉淀法制备的样品形貌对比,颗粒分布较均匀,边界清晰,且无明显团聚。荧光光谱的结果表明,所制备的纳米发光粉体LaPO4:Sm3+在可见光激发下能获得很好的发光效果,发出明亮的橙光。     

Nd:GdVO4的光谱性质及上转换发光实验研究

测量了新型激光晶体Nd:GdVO4的室温吸收光谱和近红外区荧光谱,观察到该晶体在593 nm、754 nm和806 nm附近有3个较强的吸收带,在912.2 nm、1 063.4 nm、1 082.3 nm和1 340.6 nm有4个主要发射峰.实验研究了Nd:GdVO4晶体在不同激发波长下的上转换发光情况,得到该晶体在440 nm、540nm、600 nm和668 nm附近存在的4个上转换发射峰,分析了其产生的能级跃迁机制.