A Novel Blue Emitting and Green persistent Luminescence in Ca8Mg3AlGaSi7O28:Eu2+,Ce3+ Phosphor for Emergency Lighting

Abstract

A special optical phenomenon called persistent luminescence, or long afterglow, occurs when light emission lasts for hours or even days after the stimulation is turned off. Persistent luminescent materials have attracted significant research attention and have found extensive application in a variety of fields. These include safety signage, security ink, and night-vision monitoring. Nevertheless, the majority of these compounds only glow in one color and need to be excited in the UV region of the spectrum, which restricts their applicability to particular uses. Hence, it is significant to develop long afterglow luminescent materials with color-tunable, chargeable by blue light. In this study, a persistent luminescence material Ca8Mg3AlGaSi7O28:Eu2+,Ce3+ with blue photoluminescence and blue-light excited yellowish-green persistent luminescence, is investigated. Ca8Mg3AlGaSi7O28:Eu2+ exhibits a broadband bright yellowish-green emission centering at 530 nm, which is attributed to the 4f⁷ → 4f⁶5d¹ electron transition of Eu²⁺ ions. Moreover, the color-tunable emission from bright yellowish-green to blue and with yellowish-green persistent luminescence by adjusting the Ce3+ concentration. The integration of photo-stimulated luminescence, persistent luminescence and color-tunable in this integrated luminescent Ca8Mg3AlGaSi7O28:Eu2+,Ce3+ phosphor has potential applications in emergency lighting, optical data storage and anti-counterfeiting.