CaF_2∶Dy的热释光特性研究

Study on the Thermoluminescence Properties of CaF_2∶Dy

经测量与分析得出 ,CaF2 ∶Dy受X射线辐照后在 2 5～ 2 90K及 30 0～ 670K范围内有 76、84、137、170、34 9、363、388、4 14、4 37、4 65K等热释光 (TL)峰 ,各峰均含 4个窄发光带 ,其中心波长分别为 4 80、575、675及 775nm。由X射线激发导致的辐射致发光 (RL)谱中除上述 4个窄带外在较短波长处还有宽带出现。由对发光曲线的分析中得出的动力学参数值推测 ,窄带发光可能是由较为邻近的空穴 Dy2 +贯穿势垒复合而形成 ,而宽带则可能是激子或自俘激子发光。 380K以下的TL峰在室温下很不稳定 ,可见光对上述各TL发光都有衰减作用。

The 25 290K and 300 670K thermoluminescence(TL) spectra in the X ray irradiated CaF 2∶Dy were measured and analyzed.Thermal peaks were detected at 76、84、137、170、349、363、388、414、437 and 465K with the narrow emission bands centered at 480、575、675 and 775nm.Additional broad emission bands were observed on the shorter wavelength side as well as those narrow bands in the X ray induced radioluminescence(RL)spectra.With the reference of the mechanical parameters obtiained from the analysis of the glow curves,it is suggested that the narrow band emissions were produced by the nearby hole Dy 2+ recombination though the potential barrier and the broad bands were from the exciton or self trapped exciton emissions.The thermal emissions below 380K are not thermally stable at room temperature and the visible light can bleach all those TL peaks.