在Sr_3Ca_2(PO_4)_3Cl基质中Tb~(3+)和Dy~(3+)的发光及Ce~(3+)对它们的敏化作用

本文用高温固相扩散法合成了试样。研究了在Sr_3Ca_2(PO_4)_3Cl基质中,Tb~(3+)和Dy~(3+)离子的发光性质;Ce~(3+)对Tb~(3+)和Dy~(3+)离子发光的敏化作用;计算了Ce~(3+)→Tb~(3+)和Ce~(3+)→Dy~(3+)的能量传递效率;初步探讨了Ce~(3+)→Tb~(2+)和Ce~(3+)→Dy~(3+)之间的能量传递机理。

Luminescence of Tb~3+ and Dy~3+ and the Energy Transfer from Ce~3+ to Them in Sr_3Ca_2(PO_4)_3Cl Phosphors

The luminescence and energy transfer in Sr3Ca2(PO4)Cl activated by Tb3+ or Dy3+ as well as coactivated by Ce3+ and Tb5+ and by Ce3+ and Dy3+ have been studied.In order to improve the luminescence properties of Tb3+ or Dy3+ in Sr3Ca2(PO4),Cl host, we have investigated the sensitization processes of Tb3+ and Dy3+ by the coactivated Ce3+ ions. Excitation spectra show that there appears a strong absorption band of Ce3+, in addition to the original f-f transition sharp lines of Tb3+ or Dy3+. It means that there happens a strong sensitization of Tb3+ and Dy3+ by the prescence of Ce3+ ions.The energy transfer efficiency from Ce3+ to Tb3+ and to Dy3+ in these phosphors have been determined to be 76 and 65% respectively.The mechanism for these energy transfer has been proved to be a process of mul-tipole resonance in nature.