Ce^3+/Tb^3+双掺杂SrAl2Si2O8荧光粉的发光性能及其在测温领域的应用

Optical Properties of Ce/TbCo-Doped SrAlSiO Phosphor for Temperature Sensing

采用高温固相法在弱还原气氛下制备了系列荧光粉材料Sr1-3(x+y)/2Al2Si2O8:x Ce^3+,y Tb^3+,并通过X射线衍射(XRD)、荧光光谱和荧光强度比(FIR)测温法分析了荧光粉样品的晶体结构、发光性能及其温度传感特性。XRD分析结果表明掺杂离子Ce^3+和Tb^3+均占据Sr^2+格位,并且掺杂少量的稀土离子不会改变基质的晶体结构。荧光光谱分析结果表明在近紫外光激发下,该双掺杂荧光粉的发射光谱显示出Ce^3+和Tb^3+离子的特征发射峰,最佳掺杂浓度的荧光粉化学式为Sr0.865Al2Si2O8:0.05Ce^3+,0.04Tb^3+。此外,在不同波长的监测下,测得的激发光谱形状十分相似,表明在该荧光粉中存在着Ce3+→Tb^3+能量传递过程。FIR测温法计算结果表明该荧光粉的相对灵敏度随温度的升高而升高,在520 K时有最大值为0.022 4 K^-1。研究结果表明该荧光粉具备的优异光学性能和温度传感性能使其成为一种具有应用前景的测温材料。

A series of Sr1-3(x+y)/2Al2Si2O8:xCe^3+,yTb^3+phosphors were prepared by high temperature solid state reaction under a weak reducing atmosphere. The crystal structure,optical properties and temperature sensing performance of the phosphors were analyzed by X-ray diffraction(XRD),fluorescence spectroscopy and fluorescence intensity ratio(FIR)thermometry. The XRD results show that both Ce^3+and Tb^3+occupy the Sr^2+lattices and the crystal structure of all samples do not change with the substitution of rare earth elements. The fluorescence spectra results indicate that the phosphor shows emission peaks of Ce3+and Tb3+ions under the excitation of near-ultraviolet light,and the optimal doping concentration of phosphor is Sr0.865Al2Si2O8:0.05Ce^3+,0.04 Tb^3+. In addition,the excitation spectra of the co-doped phosphor are consistent when monitored at different wavelengths,indicating that there exists Ce^3+→Tb^3+energy transfer process in the phosphor. The calculation results of FIR method show that the relative sensitivity of the phosphor increases with the increase of temperature,and the maximum value achieves 0.022 4 K^-1 at 520 K. The above results show that the excellent optical properties and temperature sensing performance of the phosphor make it become a promising material for temperature sensing.