Effect of Eu3+ on the thermal degradation and luminescence properties of Sr2Si5N8: Eu phosphors

To be better applied in light emitting diodes (LEDs), phosphors are always required a good thermal stability. As an important factor which influences the thermal stability of the phosphors, thermal degradation is decided by the oxidation of the activated ions or the host. In this paper, the process of oxidation of Sr2Si5N8:Eu2+ were studied, as well as the influence of the production of Eu3+ on the stability of the phosphors. The results suggest that the oxidation process is directly related to the content of activated ions and the treated temperature. At the same time, the production of Eu3+ will promote Eu2+ further oxidation and reduce the thermal stability of the phosphors. On the other hand, an amorphous layer on the surface was found during the holding process, which has an inhibiting effect on the oxidation of the Eu2+.