Dy^(3+)/Nd^(3+)掺杂对Sr_4Al_(14)O_(25):Eu^(2+)陷阱能级的影响

Influence of doping of Dy^(3+)/Nd^(3+) on the trap levels of Sr_4Al_(14)O_(25):Eu^(2+)

采用高温固相法合成了Sr4Al14O25:Eu2+,Sr4Al14O25:Eu2+,Dy3+和Sr4Al14O25:Eu2+,Nd3+材料,研究了Dy3+或Nd3+掺杂对Sr4Al14O25:Eu2+陷阱能级的影响.热释光谱对比显示,在Sr4Al14O25:Eu2+的热释光谱中,存在两个不同深度的陷阱能级;Dy3+掺杂提高了原有浅陷阱能级中被束缚电子的密度,从而显著提高了Sr4Al14O25:Eu2+的长余辉特性;Nd3+掺杂增加原有深陷阱能级中被束缚电子的密度.由于深陷阱能级不利于在室温下电子的逃逸,所以Nd3+掺杂不能提高Sr4Al14O25:Eu2+室温下的余辉特性.

The Sr4Al14 O25：Eu^2 ＋ ,Sr4Al14 O25：Eu^2 ＋ ,Dy^3 ＋ and Sr4Al14 O25：Eu^2 ＋ ,Nd^3 ＋ samples were synthesized by the conventional solid state reaction method. The influence of doping of Dy^3 ＋ or Nd^3 ＋ on trap levels of Sr4Al14O25：Eu^2 ＋ were studied. The results indicated that there are two trap levels with different depths,as shown in the thermoluminescence spetra of Sr4Al14O25：Eu^2 ＋ ,and the shallow trap level is suitable for electrons to escape at room temperature. The dopant Dy^3 ＋ enhances the concentration of electrons trapped by the shallow trap levels,leading to the notable increase of afterglow of Sr4Al14O25：Eu^2 ＋. The concentration of electrons trapped by deep trap levels were is by doping with Nd^3 ＋. Since the deep trap level is not appropriate for electron to escape at room temperature,the dopant of Nd3 ＋ does not improve the room temperature afterglow.