Eu2+ co-doped MgAl2O4: Mn2+ green phosphor ceramics: Anti-thermal quenching emission via trap engineering strategy

Abstract

The rapid advancement of high-power solid-state lighting highlights the importance of developing phosphor ceramics with high resistance to thermal quenching of its luminescence. Herein, a series of Eu²⁺ co-doping MgAl₂O₄: Mn²⁺ phosphor ceramics were synthesized by spark plasma sintering. The significant green light enhancement at 516 nm is attributed to Eu²⁺-Mn²⁺ energy transfer. The introduction of Eu²⁺ increases the concentration of electron trap levels and improve the luminescence intensity at 423 K from 80 % to 110 %, compared with the counterparts at room temperature. The strong correlation between trap levels and oxygen vacancies was demonstrated by the X-ray photoelectron spectroscopy and electron paramagnetic resonance analysis. Finally, the application demonstration of the optimized sample was explored through its integration with a 400 nm LED chip. This study proposes a strategy of leveraging trap levels to induce anti-thermal quenching behavior, providing some insights for the development of highly thermally stable phosphor ceramics.