Cr3+ activated Gd3Sc2Al3O12 garnet phosphor ceramic with broadband emissions and enhanced thermal stability toward high-power near-infrared LED/LD

Abstract

The development of high-quality phosphor ceramics with high photoelectric efficiencies and thermal stabilities is essential for realizing high-power broadband near-infrared light sources. In this study, a series of pure-phase Gd3Sc2Al3O12:Cr3+ near-infrared (NIR) phosphor ceramics (GdScCr NIR-PCs) exhibiting remarkable thermal stability and broadband emission were fabricated for the first time using a vacuum sintering technique. The integrated emission intensity at 423 K is 79.8 % of that at room temperature. The GdSc08Cr exhibits an emission peak at a wavelength of 785 nm, with a full width at half maximum (FWHM) of 116.9 nm under 460 nm excitation. By integrating the GdScCr NIR-PC with a blue light-emitting diode/laser diode (LED/LD) excitation source, the NIR LED prototype achieved a maximum output power of 112.19 mW at 300 mA with a photoelectric conversion efficiency of 13.64 % at 150 mA, and the NIR LD prototype achieved a maximum power output of 484.34 mW at 2.3 A. The operating temperatures of NIR-PCs were 73.1 °C at 300 mA for LED and 90.7 °C at 2.5 A for LD. Moreover, the application of the prepared GdScCr NIR-PCs for fruit and grain detection was performed. These results demonstrate that the prepared GdScCr NIR-PCs possess substantial potential for application in high-power broadband NIR spectroscopy.