A Study on thermal quenching mechanism in Sr_2Si_5N_8 :Eu red phosphors with different Eu concentration

摘要

Eu doped Sr_2Si_5N_8 red phosphors with different Eu concentration were synthesized by high-temperature solid phase method. The crystal structure, luminescence and the thermal quenching properties were investigated in detail. It was found that the thermal quenching property was largely dependent on the Eu concentration. Interestingly, the thermal quenching property for low concentration Eu doped Sr_2Si_5N_8 was greatly improved as increasing Eu concentration. In order to understand the relevant mechanism, we examined the change of relative intensity and fluorescence lifetime for the two-peak emission in Sr_2Si_5N_8: Eu. The result revealed that Eu distribution changed with increasing Eu concentration, which should be the mainly mechanism of the thermal quenching behavior for low concentration Eu doped Sr_2Si_5N_8 phosphors.