Unveiling the Potential of Sunlight‐Driven Multifunctional Blue Long Persistent Luminescent Materials via Cutting‐Edge Trap Modulation Strategies

Abstract Numerous challenges persist in the field of long persistent luminescence (LPL) materials, including the unclear mechanism of persistent luminescence, low efficiency of sunlight excitation, and limited availability of commercial materials. To address these issues, a LPL material, SrAl₂Si₂O₈:x% Eu²⁺,y% Dy³⁺, is synthesized for excitation by UV lamps or sunlight. Dy³⁺ doping remarkably extends the afterglow duration from 2 to 7 h under UV lamp excitation, exhibiting a remarkable enhancement of 350%. Notably, SrAl₂Si₂O₈:4.0% Eu²⁺, 3.0% Dy³⁺ shows 2 h afterglow duration when exposed to sunlight, surpassing other LPL materials and expanding potential applications. XPS and XANES measurements confirm Eu²⁺ as the luminescent and persistent luminescent centers, while Dy³⁺ increases trap diversity. Through meticulous analysis of the EPR and XPS data, it is elucidated that the material encompasses two distinct types of traps, namely oxygen vacancies and may be traps. This provides a basis for subsequent trap analysis in LPL materials. Microstructural analysis examined ion coordination environment changes due to Eu²⁺ and Dy³⁺ doping. The mechanical luminescent properties are characterized, and a plausible afterglow mechanism is proposed based on the experimental results, offering insights for further research into LPL materials.