CaS:Cu^+磷光体的合成及发光性质

PREPARATION AND LUMINESCENCE PROPERTIES OF CaS:Cu PHOSPHORS

本文首先用X光电子能谱分析铜在硫化钙基质中是以一价形式存在的.在掺铜的硫化钙的激发光谱中,有三个吸收峰,峰位分别为268nm、307nm和400nm;在CaS:Cu^+的发射光谱中,产生四个发射峰,峰位分别为430nm、465nm、490nm和610nm.这四个发射峰分别由不同铜离子格位产生的.在Cas:Cu^+的热释发光曲线中,显示单一热释发光峰,峰值温度为120℃,该热释发光峰有可能用作紫外剂量材料.

CaS:Cu phosphors were prepared and their luminescence properties were studied. Copper is proved to be existed as monovalence in calcium sulphide from X-ray photoelectron spectra. In excitation spectra of CaS:Cu phosphors, three peaks have been observed. The peaks locate at 268nm,307nm and 400nm respectively.The peak of 268nm is overlapped between the excited state 1T2 (37700cm-1) of Cu+ ions and the absorption edge of calcium sulphide, The peak of 307nm is caused by the excited state 1E(32500cm-1) of Cu+ ions. The peak of 400nm is produced by the transformation process of Cu+???????????Cu2++ e.In emission spectra, four peaks have been observed. The peaks locate at 430nm, 465nm, 490nm and 610nm respectively. When the excitation wavelength is fixed at 268nm, 307nm and 400nm respectively, the emission spectra of CaS:Cu phosphors are different from each other. When the excitation wavelength is at 268nm, the emission spectra show two peaks at 430nm and 465nm and a shoulder at 490nmf When the excitation wavelength is at 307nm, the peak of 490nm dominates and the other two show shoulders. When the excitation wavelength is at 400nm, a single peak of 490nm exists. The emission spectrum of CaS: Cu phosphors change with copper concentration complicatedly. The peak of 430 migrates to longer wavelength with the increase of copper concentration. It is caused by Cu'ca- V23+centers. The peaks of 465nm and 490nm are separately produced by interstitial and substitutional Cu+ ions. The peak of 610nm only exists with more amount of copper.It is caused by Cu2S.In the TL glow curves of CaS:Cu phosphors, a single peak has been observed. The peak temperature is about 120??CCCCCCCCCC and it is very useful for dosimetry. The TL output of CaS:Cu phosphors is linearly changed with the UV absorb dose. So, the CaS:Cu phosphors are possible to be used in UV radiation dosimeter in the future.