High-thermal-stability SrLaMgSbO6: Cr3+ phosphors for night vision and nondestructive testing

In this study, a novel near-infrared (NIR) emitting double-perovskite phosphor SrLaMgSbO 6 :Cr 3+ (SLMSO: Cr 3+ ) was prepared through a solid-state reaction method. Through systematic investigation of Cr 3+ concentration-dependent photoluminescence properties, we identified SLMSO:0.02Cr 3+ as the optimal concentration composition exhibiting superior optical characteristics . Comprehensive characterization techniques were employed to analyze the crystal structure, morphological features, excitation-emission profiles, and crystal field environment of the developed phosphor. The as-synthesized phosphor demonstrates remarkable broadband NIR emission centered at 850 nm upon 520 nm excitation, which is attributed to the 4 T 2 → 4 A 2 transition of Cr 3+ ions in the weak crystal field environment of the double-perovskite host. A particularly noteworthy finding is the exceptional thermal stability of the material, maintaining 86.7 % of its room-temperature (298 K) emission intensity at 423 K. Finally, we fabricated a NIR pc-LED device by integrating the optimized SLMSO:0.02Cr 3+ phosphor with a commercial 530 nm LED chip, promising applications in night vision technology and penetration imaging systems . The combination of broadband NIR emission, superior thermal stability, and efficient excitation by commercial LED chips positions this novel phosphor as a significant advancement in the field of NIR-emitting materials for practical applications.