Temperature‐Dependent Emission Spectra of Ca ₂ Si ₅ N ₈ : Eu ²⁺ , Tm ³⁺ Phosphor and its Afterglow Properties

Abstract

The nitrides Ca 2 Si 5 N 8 :0.5% Eu 2+ , x % Tm 3+ ( x = 0, 0.5, 1, 2, 4) ( CSN :0.5E, x T) phosphors were prepared via the high temperature solid‐sintering method using CaH 2 as calcium source. These phosphors exhibited strong orange long‐lasting phosphorescence ( LLP ) after turning off the activating light. Besides, the CSN :0.5E, 1T phosphor with an afterglow time of more than 200 min (0.32 mcd/m 2 ). Furthermore, the temperature‐dependent emission spectra of CSN :0.5E, 1T were investigated from temperature 80–500 K and an anti‐quenching phenomenon that the emission intensities increased then decreased under excitation at increased temperature was found. Ultimate, the proposed mechanism on temperature dependence of luminescence was analyzed. This study provides a new perspective for the impact of temperature‐dependent problem as a consequence of heating processes in luminescent materials.