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.

Development of a novel Eu2+ activated oxonitridosilicate cyan phosphor for enhancing the color quality of a violet-chip-based white LED

“…3g) indicates that Eu 3d is composed of 3d 3/2 with a binding energy of 1153.18 eV and 3d 5/2 with a binding energy of 1127.88 eV. These two binding energies belong to Eu 2+ 3d 3/2 and Eu 2+ 3d 5/2 , respectively, 55,56 confirming that the valence state of the doped europium ion is +2.…”