Ultra-efficient broadband NIR garnet phosphor via Ca2+-Sn4+/In3+-Al3+ double ion pair synergistical-substitution for multifunctional pc-LED applications in plant growth and night vision biological detection and information encryption

Near-infrared phosphor conversion light emitting diode (NIR pc-LED) has important application value in plant growth, night vision imaging and biological detection. Its performance depends on the optimized design of fluorescent materials. Based on gadolinium gallium garnet (Gd 3 Ga 5 O 12 ), the near-infrared phosphors of Gd 2.5 (CaSn) 0.5 (InAl) 0.5 Ga 3.5-x O 12 : xCr 3+ (x = 0.01–0.09) were prepared by Ca 2+ -Sn 4+ /In 3+ -Al 3+ double ion pair synergistic substitution strategy. Under excitation of 450 nm blue light, the material exhibits broadband near-infrared emission covering the range of 650–1150 nm, with a quantum yield of 96.29 %. The material exhibits excellent thermal stability of luminescence and can maintain 82.4 % of the initial emission intensity at room temperature at 423K. The NIR pc-LED device based on this phosphor package achieved 67.37 mW output power and 16.68 % photoelectric conversion efficiency at 100 mA driving current. Application verification shows that the NIR pc-LED light source shows excellent performance in plant supplementary light, night vision security, information encryption and nondestructive testing applications. It fully proves that the broadband near-infrared emission of this series of phosphors can take into account multi-functional application scenarios and has broad development prospects.