A novel 410 nm excitable Y3Ga3MgSiO12: Ni2+ garnet phosphor for ultra-wide broadband emission toward NIR III region and its application

Abstract

The performance of near-infrared phosphor-converted light-emitting diodes (NIR pc-LEDs) is largely determined by the applied NIR-emitting phosphors. Phosphors activated by Ni²⁺ show promising luminescence in the NIR-II region but are commonly excited by 365 nm ultraviolet chips. Although Cr³⁺-Ni²⁺ co-doped materials can be efficiently excited by blue chips, this approach imposes strict lattice requirements and necessitates the simultaneous incorporation of both Cr³⁺ and Ni²⁺ ions into the lattice structure. In this study, we present a novel Ni²⁺-activated garnet phosphor, Y₃Ga₃MgSiO₁₂: Ni²⁺ which can be excited by 410 nm light. The Ni²⁺ ions are located in the octahedral sites of [MgO₆] and [Ga₁O₆]. Two significant advancements are made in the Y₃Ga₃MgSiO₁₂: Ni²⁺ phosphors: One is the shift of the ideal excitation wavelength from UV to 410 nm, which can greatly reduce the damage of ultraviolet light to the encapsulated pc-LED and the phosphor. The second is the realization of ultra-wideband and continuous emission of NIR-II-III region (1000–1850 nm, full width at half maximum of 314 nm). The optimal excitation wavelength is identified as 406 nm, and a prominent NIR emission at 1470 nm is achieved. Compared with the Y₃Ga₅O₁₂, the luminescence intensity was 4.5 times enhanced after Mg²⁺/Si⁴⁺ substitution. The effect of Mg²⁺/Si⁴⁺ substitution on the luminescence properties is systematically elucidated. The Y₃Ga₃MgSiO₁₂: 0.03 Ni²⁺ phosphor, when coupled with commercially available 410 nm blue light chips, demonstrates the promising potential for applications in NIR pc-LEDs and night vision. This work paves the way for the future development of highly efficient, ultra-wideband near-infrared emitting phosphors.