热释光和光释光发光谱的测量

介绍了自行研制的计算机化热释光和光释光三维光谱测量装置的系统结构及其工作原理.在计算机的控制下,通过精密加热器或激发光源以热激发或光激发的方式使样品发光.从样品发出的光经过光路和光栅分光系统后,形成光谱,被高灵敏度的CCD采集,再将光谱图像模拟信号变为可以直接用计算机进行数据处理的数据信号.波长范围200~800nm,波长分辨率优于2nm,人机界面友好,操作方便.利用热释光和光释光三维光谱测量装置测量了SrSO₄:Eu(0.1%,摩尔分数)和CaSO₄:Eu(0.1%,摩尔分数)的光释光发光谱和热释光发光谱,得到SrSO₄:Eu的光释光发光波长与热释光发光波长均为375nm,而CaSO₄:Eu的光释光发光波长与热释光发光波长均为385nm,说明热释光和光释光具有相同的发光中心,均来自于Eu²⁺的能级跃迁.同时在CaSO₄:Eu的热释光发光谱中还观察到了Eu³⁺的发光.与二维发光曲线相比较,通过对三维热释光和光释光发光谱的研究,可以得到更丰富的信息,这有助于对热释光和光释光发光机制进行更深入的研究.

Measurement of Thermoluminescence Spectra and Optically Stimulated Luminescence Spectra

A computerized system used for measuring three dimensional emission spectra of thermoluminesence(TL)and optically stimulated luminescence(OSL)is introduced.The system is composed of heating system,optical stimulation sources,optic spectrometer,and computer system.The sample is coupled to the spectro-meter through a fiber optic cable.When the sample is stimulated by heating or light irradiation,the TL or OSL signal will be decomposed into spectrum by a diffraction grating,and the spectrum is collected by a charge coupled device(CCD)with high sensitivity,and then a high speed ADC converts the analog signal of spectrum image to digital signal which can directly be dealt with the computer.The wavelength range of the spectrometer is from 200 nm to 800 nm.All programming was done in VC⁺⁺ 6.0.The man-machine interface is friendly and the operation is easy and efficient.As an example,the TL and OSL emission spectra of SrSO₄:Eu(0.1%,mol fraction)and CaSO₄:Eu(0.1%,mol fraction)were measured with satisfying results.Thermoluminescence(TL)and optical stimulated luminescence(OSL)emission spectra of SrSO₄:Eu(0.1%)and CaSO₄:Eu(0.1%)were measured.The results illuminate that the TL and OSL emission wavelengths of SrSO₄:Eu are 375 nm,and those of CaSO₄:Eu are 385 nm.The TL and OSL emission spectra also indicate that TL and OSL have the same luminescence centers,and the luminescence comes from transitions between energy levels of Eu²⁺.The luminescence of Eu³⁺ is observed in the TL emission spectrum of CaSO₄:Eu as well.From the 3-dimensional spectra,more information about luminescence can be used to perform further studies on the kinetics of TL and OSL materials.