稀土掺杂荧光粉的光学性能及其测温应用研究

Optical Properties of Rare Earth Doped Phosphors and Its Application in Temperature Sensing

为研究Ca_(3)La_(3)(BO_(3))_(5):Dy^(3+)(CLBD)荧光粉的温度传感特性,采用传统高温固相法在还原气氛下制备了系列镝离子掺杂的硼酸镧钙荧光粉材料。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、紫外可见分光光度计和荧光光谱仪表征了CLBD(x=0.12)荧光粉样品的晶体结构、形貌、发光性能和温度传感特性。XRD结果表明,镝离子成功掺杂CLB基质,取代镧离子位点并形成单相。SEM结果表明,样品呈现团聚,粒径0.5~3.0μm。漫反射光谱结果表明:CLBD荧光粉在紫外光范围内具有宽的吸收带。荧光光谱表明:该荧光粉可被紫外光有效激发,发射峰位于454、485、578和668 nm。由于镝离子的^(4)I_(15/2)和^(4)F_(9/2)的能级差为1408 cm^(-1),满足热耦合能级的条件(200~2000 cm^(-1)),可用于光温传感。荧光强度比温度传感分析表明:在298~573 K的温度范围内,CLBD荧光粉的绝对灵敏度随温度升高而增大,相对灵敏度在350 K时达到最大值0.0194 K^(-1)。优异的光学性能、宽的温度测量范围和高的灵敏度表明CLBD荧光粉在温度传感方面具有良好的应用前景。

To study the temperature sensing properties of Ca_(3)La_(3)(BO_(3))_(5):Dy^(3+)(CLBD)phosphors,a series of Dy^(3+)-doped Ca_(3)La_(3)(BO_(3))_(5)phosphor materials were prepared by traditional high temperature solid-phase method in a reducing atmosphere.The crystal structure,topography,luminescence properties and temperature sensing properties of CLBD(x=0.12)phosphor samples were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),ultraviolet-visible spectrophotometer and fluorescence spectroscopy,respectively.XRD results show that dysprosium ions are successfully doped into the Ca_(3)La_(3)(BO_(3))_(5)matrix,and replace the lanthanum ions sites and form a single phase.SEM results show that the samples form some agglomerations and the particle sizes are 0.5-3.0μm.Diffusive reflection spectra results show that CLBD phosphors have a wide absorption band in the ultraviolet range.Fluorescence spectra indicate that the phosphors can be effectively excited by ultraviolet light,with emission peaks at 454,485,578 and 668 nm.The energy level difference between ^(4)I_(15/2) and ^(4)F_(9/2) of dysprosium ions is 1408 cm^(-1),which satisfies the condition of thermal coupled energy levels(200-2000 cm^(-1))and can be used for optical temperature sensing.Fluorescence intensity ratio temperature sensing analysis demonstrates that in the temperature range of 298-573 K,the absolute sensitivity of CLBD phosphors increases with the increase of temperature,and the relative sensitivity reaches the maximum value of 0.0194 K^(-1)at 350 K.Excellent optical properties,wide temperature measurement range and high sensitivity indicate that the CLBD phosphors have a good application prospect in temperature sensing.