Insights into luminescence quenching and detecting trap distribution in Ba2Si5N8:Eu2+ phosphor with comprehensive considerations of temperature-dependent luminescence behaviors

Abstract

Probing intrinsic luminescence behaviors in known inorganic hosts is still of great importance to understand corresponding mechanisms and guide their possible applications. Nitride phosphor Ba₂Si₅N₈:Eu²⁺, which shows interesting reddish-orange persistent luminescence but more famous for phosphor-conversion in white-LEDs, lacks adequate inquiries about two-peak emission, the full temperature range of thermal quenching and trap distribution. In this article, temperature-dependent photoluminescence, afterglow decay curves and photo-stimulated persistent luminescence of Ba₂Si₅N₈:Eu²⁺ phosphors were investigated in detail. Evaluation of energy transfer at two emitting sites and luminescence quenching was based on careful investigation of photoluminescence at various temperatures. Furthermore, we proposed an integrated temperature-dependent afterglow decay curve method to estimate the trap density distribution in Ba₂Si₅N₈:Eu²⁺ phosphor, accompanied by thermo-luminescence and photo-stimulated persistent luminescence analysis. Results indicate that integrating afterglow decay curves of various temperatures can be a useful attempt to detect trap distribution in charge carrier trapped materials.