Broadband Near-Infrared Sr₃Al_9.8SiO₂₀:0.2Cr Phosphor Realized by Crystallographic Site Engineering

Broadband near-infrared (NIR) phosphor-converted devices play a vital role in emerging applications of imaging, medicine, agriculture, etc. Herein, a series of economical broadband NIR-emitting Sr₃Al_10-SiO₂₀:xCr (SASO:xCr) phosphors with tunable bandwidths and emission peaks were realized by tailoring the Cr³⁺ doping concentration. The optimal Sr₃Al_9.8SiO₂₀:0.2Cr (SASO:0.2Cr) phosphor exhibits a broadband emission with full width at half-maximum ∼ 140 nm, and the internal/external quantum efficiency and thermal stability of the SASO:0.2Cr were measured to be 68%/37% and 77%@380 K, respectively. An NIR phosphor-converted light-emitting diode (NIR pc-LED) device was fabricated by combining a blue LED chip with the SASO:0.2Cr phosphor. The applications of NIR pc-LED on plant growth promotion, night vision, and medical imaging were demonstrated. We reported an economical broadband NIR phosphor with multiple potential applications and highlighted the crystallographic site engineering strategy to explore broadband phosphors based on aluminates.