CaAl_2Si_2O_8∶Eu,Ce,Tb单基三元掺杂荧光材料的制备及其光谱学特征研究

采用高温固相法制备了CaAl_2Si_2O_8∶Eu,Ce,Tb单基三元掺杂的荧光材料。使用X射线衍射仪(XRD)、拉曼光谱仪(Raman)和荧光分光光度计(PL)等测试手段对该荧光材料进行表征。采用XRD表征了样品的物相组成,测试结果表明稀土离子Eu~(2+)置换Ca~(2+)并没有引起CaAl_2Si_2O_8基质晶格结构的变化。拉曼光谱分析证实了样品中硅氧四面体和铝氧四面体的存在,表明了Eu~(2+)替代Ca~(2+)的数量与晶体形态畸变程度有关,Eu~(2+)进入基质晶格的数量影响着硅(铝)氧四面体的数量。PL测试结果表明样品在325nm光激发下,其发射峰主要表现为426nm(蓝光区)的强宽带发射峰和541nm(绿光区)的弱发射峰,其中426nm处的宽带发射峰可通过高斯拟合成三个位于393,419和474nm的拟合峰;对比分析荧光性能以及同等合成条件下样品荧光强度的不同,确定了该荧光材料在三掺Eu∶Ce∶Tb的摩尔比为1∶1∶1.5时所发射荧光最强。CIE色度图坐标显示三种掺杂比例下制备的荧光材料均发射蓝色荧光,光显色性好,色温低,是一种适合作为紫外-近紫外激发的LED用蓝色荧光材料。

Preparation and Spectroscopic Characteristics of CaAl2Si2O8∶ Eu,Ce, Tb Fluorescent Material

CaAl2Si2O8 ∶ Eu,Ce,Tb fluorescent material were synthesized with high temperature solid phase method.The fluorescent materials were characterized with fluorescence spectroscopy (PL),Raman spectroscopy (Raman) and X-ray diffraction (XRD).The phase compositions of the samples were studied with XRD.It was shown that the Eu2+ substitution of Ca2+ did not induce the changes of the structure of the matrix.Raman spectroscopy confirmed the presence of silicon-oxygen tetrahedron and aluminum oxygen tetrahedrons.Raman spectra also confirmed that the amount of Eu2+ substitution Ca2+ was related to the degree of crystal morphology distortion.PL spectra of the samples shows that the emission peak at 325 nm wavelength excitation,the emission peak of the sample was shown to be a strong emission peak at 426 nm (blue region) and a weak emission peak at 541 nm (green region).The emission peaks can be fitted with Gaussian to three fitting peaks at 393,419 and 474 nm.After combining the analysis and comparison,and ultimately determine when Eu ∶ Ce ∶ Tb=1 ∶ 1 ∶ 1.5 the sample shows the strongest fluorescence intensity.CIE chromaticity diagram shows that the samples are emitting blue fluorescence.The material has good color rendering,color temperature is low,which is a kind of suitable blue fluorescent LED material with ultraviolet and near ultraviolet excitation.