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1.
赖欣  秦丹  李玥  魏艳艳  高道江  毕剑 《材料导报》2011,25(12):49-51,55
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。  相似文献   

2.
孙岚陈朝  林昌健 《功能材料》2004,35(Z1):462-463
用直流电沉积法在多孔氧化铝模板中制备了高度有序的CdS纳米线阵列,SEM和XRD的观察和测量表明,CdS纳米线尺寸均匀、排列规整,具有六方纤锌矿结构,Cd和S的化学计量比为11.CdS纳米线阵列的光致发光测量显示,激发波长为325nm时,CdS纳米线阵列在450nm处有一强的PL峰,在484nm处还有一肩峰.对其光致发光机理进行了分析.  相似文献   

3.
欧阳艳  张晓蓉  王静  王茜  何晓燕 《材料导报》2016,30(10):33-37, 56
采用微波法合成了四方晶系的CaWO4∶Eu~(3+)红色荧光粉。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、光致发光光谱(PL)等分析手段对样品的结构、形貌以及发光性能进行了表征。研究了结构控制剂种类、PEG添加量、Eu~(3+)掺杂浓度、设置温度、反应物浓度等对合成CaWO4∶Eu~(3+)发光材料的发光性能以及形貌的影响。实验结果表明,所合成四方晶系的CaWO4∶Eu~(3+)红色荧光粉在393nm紫外激发下的发射主峰位置在614nm处。当反应条件分别为PEG添加量为1.00g、Eu~(3+)掺杂浓度20%、设置温度为120℃、反应物浓度为0.06mol/L时样品具有最强的发光强度。在紫外灯照射下,样品呈现出明亮的红色。  相似文献   

4.
利用水热法制备出了不同形貌的白钨矿结构的BaMoO4粉体材料,样品的结构、形貌及光致发光性能利用XRD、Raman、FESEM和PL谱进行了表征,探讨了工艺参数对BaMoO4材料形貌的影响。通过调整反应温度、反应pH值和表面活性剂CTAB浓度可以调控BaMoO4材料的形貌,得到了棱锥状、多面体及树枝状等形貌的BaMoO4材料。BaMoO4样品的室温光致发光谱是由发光中心在约540nm处的单一绿光组成,样品的形貌不同发光强度不同。  相似文献   

5.
以制备氧化铝模板为前提,采用电场辅助沉积法制备了纳米针尖阵列、纳米管阵列和纳米线阵列。利用X射线衍射仪、扫描电镜、透射电镜、能谱仪、热重分析等检测手段对制备的样品进行了相应的分析和表征。采用近场光学扫描显微镜和荧光分光光度计研究了样品的发光性能,并分析了发光机理。本实验的研究步骤、内容及得到的结论如下:(1)通过二次阳极氧化法制备了高度有序的氧化铝模板。在草酸溶液中合成了半壁氧化铝纳米管阵列,其阵列在302nm处的发射峰是由1B→1A的电子跃迁引起的,属于F+型发光。最后制备了氧化铝微米树,其树干的形成沿不同方向生长,呈明显的X交叉型生长模式。(2)制备出ZnO纳米针尖阵列。通过X射线衍射分析和高分辨图,可以判断该ZnO为多晶结构,且在[101]方向上有择优生长的趋势。随着退火温度的升高和退火时间的延长,510nm处的绿光发射带减弱,而379nm附近的带边发射增强。(3)合成了ZnO∶Tb3+纳米管阵列。通过对发射光谱图的分析,可以判断344nm处新的紫外发射带是由氧化铝模板本身发光而产生的。(4)合成了ZnO∶Eu3+纳米线阵列。高分辨透射电镜图和傅里叶变换可以断定该ZnO∶Eu3+纳米线是单晶结构,并且沿...  相似文献   

6.
纳米Sr2MgSi2O7:Eu2+,Dy3+的长余辉发光行为   总被引:2,自引:0,他引:2  
使用溶胶-凝胶技术合成纳米尺度的Sr2MgSi2O7Eu2+,Dy3+长余辉发光材料,比较了该方法与固相法获得的长余辉粉体的光致发光行为和长余辉性能.溶胶-凝胶获得的纯相Sr2MgSi2O7Eu2+,Dy3+长余辉粉体是由纳米尺度的微晶形成的团聚颗粒,具有光致发光行为和长余辉发光特性.其发射峰位于465nm.而固相合成的粉体具有两个发射峰,分别位于404nm和459nm.产生这些差别的原因在于Eu2+在基质晶格中的不同配位情况.固相合成的粉体的余辉发光性能高于溶胶-凝胶粉体,其原因在于高温固相合成在基质内部产生了更高浓度的电子陷阱.  相似文献   

7.
采用双离子束溅射法制备了SiOx:C非晶薄膜,在室温下可观察到薄膜样品有强的420nm(紫光)、470nm(蓝绿光)的光致发光(PL).分别对样品在不同温度下退火后,PL测试显示随着退火温度的升高420nm处的峰带逐渐增强变为强的发光峰;470nm处的发光峰位来自于硅基薄膜中富硅引起的中性氧空位缺陷(O3≡Si-Si≡O3),是由与氧原子配位的二价硅的单态-单态之间的跃迁所致;420nm范围的峰带可能来自于薄膜中由C单质、以及Si、O、C三者组成的一个复杂结构.  相似文献   

8.
采用CVD法以金属镓(Ga)和氨气(NH3)为原料,在镀有Al膜的蓝宝石衬底上成功地制备了GaN多晶薄膜。采用高分辨X射线衍射仪(HRXRD)、场发射电子扫描电镜(FESEM)、原子力显微镜(AFM)和光致发光能谱(PL)对样品进行了成分、形貌、表面粗糙度和发光性能分析。结果表明,制备的GaN薄膜为结晶性较好的六方纤锌矿GaN多晶薄膜,用266nm的激光作为激发光源时,光致发光谱中除出现354nm的近带边发射峰外,同时还观察到中心波长位于530nm附近的黄光发光峰及中心波长位于约637nm的红光发光峰。  相似文献   

9.
采用常压化学气相沉积法(APCVD)在玻璃衬底上制备出SnO2薄膜,对薄膜的结构和光致发光性质及退火处理对薄膜结构和发光特性的影响进行了研究.制备SnO2薄膜为六角金红石结构,最大晶粒尺寸约为1000nm.室温光致发光(PL)谱测量表明,在396nm处存在强的发光峰.研究了退火处理对发光性质的影响,并对辐射机理进行了探索.  相似文献   

10.
纳米Sr2MgSi2O7:Eu2+,Dy3+的长余辉发光行为   总被引:20,自引:0,他引:20  
使用溶胶-凝胶技术合成纳米尺度的Sr2MgSi2O7:Eu^2 ,Dy^3 长余辉发光材料,比较了该方法与固相法获得的长余辉粉体的光致发光行为和长余辉性能.溶胶.凝胶获得的纯相Sr2MgSi2O7:Eu^2 ,Dy^3 长余辉粉体是由纳米尺度的微晶形成的团聚颗粒,具有光致发光行为和长余辉发光特性.其发射峰位于465nm.而固相合成的粉体具有两个发射峰,分别位于404nm和459nm.产生这些差别的原因在于Eu^2 抖在基质品格中的不同配位情况.固相合成的粉体的余辉发光性能高于溶胶-凝胶粉体,其原因在于高温固相合成在基质内部产生了更高浓度的电子陷阱.  相似文献   

11.
Nano-submicrostructured CaWO4, CaWO4 : Pb2+ and CaWO4 : Tb3+ particles were prepared by polyol method and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR), thermogravimetry-differential thermal analysis (TG-DTA), photoluminescence (PL), cathodo-luminescence (CL) spectra and PL lifetimes. The results of XRD indicate that the as-prepared samples are well crystallized with the scheelite structure of CaWO4. The FE-SEM images illustrate that CaWO4 and CaWO4 : Pb2+ and CaWO4 : Tb3+ powders are composed of spherical particles with sizes around 260, 290, and 190 nm respectively, which are the aggregates of smaller nanoparticles around 10-20 nm. Under the UV light or electron beam excitation, the CaWO4 powders exhibits a blue emission band with a maximum at about 440 nm. When the CaWO4 particles are doped with Pb2+, the intensity of luminescence is enhanced to some extent and the luminescence band maximum is red shifted to 460 nm. Tb(3+)-doped CaWO4 particles show the characteristic emission of Tb3+ 5D4-7FJ (J = 6 - 3) transitions due to an energy transfer from WO4(2-) groups to Tb3+.  相似文献   

12.
Nanostructured CaWO4, CaWO4:Eu3+, and CaWO4:Tb3+ phosphor particles were synthesized via a facile sonochemical route. X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, photoluminescence, low voltage cathodoluminescence spectra, and photoluminescence lifetimes were used to characterize the as-obtained samples. The X-ray diffraction results indicate that the samples are well crystallized with the scheelite structure of CaWO4. The transmission electron microscopy and field emission scanning electron microscopy images illustrate that the powders consist of spherical particles with sizes from 120 to 160 nm, which are the aggregates of even smaller nanoparticles ranging from 10 to 20 nm. Under UV light or electron beam excitation, the CaWO4 powder exhibited a blue emission band with a maximum at 430 nm originating from the WO4/2- groups, while the CaWO4:Eu3+ powder showed red emission dominated by 613 nm ascribed to the 5D0 --> 7F2 of Eu3+, and the CaWO4:Tb3+ powders showed emission at 544 nm, ascribed to the 5D4 --> 7F5 transition of Tb3+. The PL excitation and emission spectra suggest that the energy is transferred from WO4/2- to Eu3+ CaWO4:Eu3+ and to Tb3+ in CaWO4:Tb3+. Moreover, the energy transfer from WO4/2- to Tb3+ in CaWO4:Tb3+ is more efficient than that from WO4/2- to EU3+ in CaWO4:Eu3+. This novel and efficient pathway could open new opportunities for further investigating the novel properties of tungstate materials.  相似文献   

13.
An environmentally friendly route for the synthesis of hierarchical CaWO4 microspheres with novel morphology at room temperature has been successfully developed. CaCl2 and Na2WO4 were used as reaction regents, and distilled water was used as an environmentally friendly solvent. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence spectroscopy. This green wet-chemical route provides a simple, one-step, low-cost approach for the large-scale synthesis of hierarchical CaWO4 microspheres with relatively uniform diameters of 3-6 microm. The hierarchical microspheres are built up with numerous nanorods with an average diameter of 50 nm, which are radially oriented to the microsphere center. SEM observations of different intermediates indicate the possible growth process, in which the hierarchical structure growth is from nuclei through kayak-like, rod-like, peanut-like, dumbbell-like, and peach-like structures to final microspheres, via "self-assembled preferential end growth" of kayak-like particles in aqueous solution. The hierarchical CaWO4 microspheres exhibit a strong, broad blue emission peak of 412 nm.  相似文献   

14.
The multicolor patterned luminescent films of CaWO(4):Eu(3+) (red), CaWO(4):Tb(3+) (green), and pure CaWO(4) (blue) on quartz substrates were fabricated by the facile and low-cost microcontact printing (μCP) method combining with the Pechini sol-gel route. On the basis of the μCP process, a hydrophobic self-assembled monolayer (SAM) was first created on the hydrophilic surface of quartz substrates by poly(dimethylsiloxane) (PDMS) mold printing, and then, the multicolor patterned luminescent films were selectively deposited on the hydrophilic regions via a spin coating process and heating treatment. The X-ray diffraction, optical microscopy, scanning electron microscopy, and photoluminescence (PL) spectra were used to characterize the structure and fluorescence properties of the corresponding samples. The results demonstrate that the μCP process can be used for patterning the inorganic phosphor materials and have potential for fabricating rare-earth luminescent pixels for the applications of display devices.  相似文献   

15.
Journal of Materials Science: Materials in Electronics - In this paper, CaWO4 nanoparticles were prepared by the hydrothermal method using the temperature of 100 (CaWO4-100), 120 (CaWO4-120), 140...  相似文献   

16.
A fabrication method for one-step anodization of an anodic aluminum oxide (AAO) template with nanopore arrays using pretreated high purity aluminum foil is reported in this article. Morphology of the AAO was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Results showed that porous AAO with ideal nanopore arrays can be fabricated by one-step anodization fabrication technology on high purity aluminum foil which had been anodized at 45?V direct current (DC), in 0°C, 0.5?M H2C2O4 solution for 48 hours. The average pore diameter and the interpore distance were 80?nm and 120?nm, respectively. Nanopores in porous AAO had very narrow size distribution and were arranged into hexagonal array. The formation mechanism of nanopore arrays in porous AAO is discussed. Porous AAO with ideal nanopore arrays provide an ideal template for preparation of many one-dimensional nanomaterials. One-step anodization of AAO is a simpler procedure and more applicable in industrial application than the previous two-step anodization technology.  相似文献   

17.
采用真空灌注结合溶胶-凝胶和氧化铝模板法,在多孔氧化铝模板中制备了平均直径为50 nm的NiFe2O4纳米线阵列.X射线衍射结果显示所制备的纳米线是纯相的NiFe2O4纳米线,透射电镜和电子衍射的结果显示已制备的纳米线是多晶的且表面光滑,场发射扫描电镜图片显示纳米线是大面积且平行有序的、纳米线的长度和所用的氧化铝模板的厚度相当.磁测量的结果显示此纳米线阵列有形状各向异性,同块状材料相比矫顽力有所增强.对纳米线的生长机理做了简单的讨论.  相似文献   

18.
以三氯化铝和叠氮化钠为原料,利用复分解反应法在温度为650℃条件下反应3h,成功地制备出呈灰白色粉末的一维单晶氮化铝纳米材料,通过对样品进行XRD、TEM和SAED测试,结果表明,样品为表面光滑的长直形圆柱状六方结构的氮化铝,直径为50nm左右,长度在几个微米以上,晶格常数分别为a=0.268nm,c=0.498nm;AlN紫外吸收谱的研究表明,AlN样品在202nm处具有一个尖锐吸收峰,其对应禁带宽度值约为6.14eV,并采用气-固(VS)生长机理、择优取向原理对一维单晶纳米线的生长进行了解释。  相似文献   

19.
甘氨酸燃烧法合成Sr2CeO4及其发光性质研究   总被引:2,自引:0,他引:2  
为制备具有优良性能的蓝色荧光粉,首次采用甘氨酸-硝酸盐燃烧法合成了Sr2CeO4,利用热重-差热分析仪、X射线粉末衍射仪、扫描电镜等技术对其形成过程、物相结构、形貌粒度、发光性质进行了研究.结果表明:燃烧后的前驱物经800℃焙烧已有目标产物Sr2CeO4生成,1100℃时可得到较纯正交晶系的Sr2CeO4相.颗粒的形貌为不规则球形,平均粒径在80 nm左右.发光性质研究表明:Sr2CeO4荧光粉的激发光谱是宽带双峰结构,此宽带属于Ce4+的电荷迁移带,两个峰分别位于305 nm和348 nm,后者为主峰.用348 nm紫外光激发样品,发出明亮的蓝光,其发射光谱也是一个宽带,最大峰位于470 nm,此峰属于Ce4+的f→t1g跃迁.发光强度在800~1100℃随温度升高而增强.  相似文献   

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