Multimodal Luminescence from LaAlO₃:Eu³⁺ via Trap Modulation for High‐Temperature Applications

Persistent phosphors with high charge storage capacity are promising for a wide range of applications, mostly demonstrated at room temperature. Designing such long‐persistent phosphor (LPP) applicable at higher temperature is largely unexplored and challenging. To prevent spontaneous charge release and ensure long‐term data retention, high‐temperature LPPs must feature multilevel traps with sufficient activation energies. In this report, LaAlO 3 :Eu 3+ (LAO:E) phosphor is investigated with multiple traps and four integrated luminescent emissions: down‐conversion photoluminescence and radioluminescence, thermally stimulated luminescence, persistent luminescence (PersL), and optically stimulated luminescence (OSL). Unlike earlier optical storage phosphors, our LAO:E phosphor possesses charge carriers that are released from these traps, ranging from shallow trap 1 to deep trap 4, across various temperatures. The potential for the long‐term storage of charge carriers at both room and elevated temperatures is also examined. Supported by experimental data and density functional theory calculations, we establish a correlation between the various traps and the desired PersL and OSL properties of the LAO:E phosphor. Additionally, a comprehensive trapping–detrapping mechanism for charge carriers is developed. The studies here are expected to pave the way for designing advanced multimode phosphors for a wide range of applications at high temperatures.