Stable near-infrared luminescence from KMgF3:Cr3+ fluoroperovskite phosphor for light-emitting diodes

The growing demand of high-performance near-infrared (NIR) phosphors has sparked significant globe interest. In this study, we present a thermally stable NIR-emitting fluoroperovskite phosphor, KMgF 3 :Cr 3+ , synthesized via a hydrothermal method through substitution of Mg 2+ with Cr 3+ . The physicochemical and spectroscopic properties, including crystal structure, bandgap, morphology, spectral feature, and photoluminescence thermal stability, were systematically investigated. Results reveal that KMgF 3 :Cr 3+ exhibits a broadband NIR emission spanning 600-1000   nm (peaking at 780   nm) under blue light excitation and demonstrates exceptional thermal stability, retaining 86% of its room-temperature emission intensity at 423   K. Leveraging these properties, we fabricated a prototype light-emitting diode by coupling the KMgF 3 :Cr 3+ phosphor with a blue InGaN chip. The resulting device enabled high-contrast night vision imaging and clear visualization of human palm veins, highlighting its potential for advanced spectroscopic applications.