Abstract
The degradation of a green-emitting phosphor Y_3 (Al, Ga)_5O_<12> : Tb by an electron bombardment was reduced with introducing Yb or Sc. The traps in these samples were evaluated by measuring thermoluminescence data. As for Yb, traps related to Yb increased and the color centers decreased with increasing Yb concentration. It shows that the influence of color centers is suppressed by the traps related to Yb. On the other hand, no new traps related to Sc were observed, and the color centers decreased with increasing Sc concentration. It suggests the formation of color centers is suppressed by adding Sc.
