Garnet-structured fluoride phosphors are attractive for phosphor-converted near-infrared light-emitting diodes (NIR pc-LEDs) owing to their broadband emission and thermal stability. Herein, pure-phase Na$_3$Al$_{2-x}$Cr$_x$Li$_3$F$_{12}$ (x = 0--0.16; NALF:Cr$^{3+}$) phosphors were synthesized hydrothermally, and their structure, morphology, crystal field, and luminescence were systematically investigated. Crystal-field analysis yielded a Dq/B of $\sim$2.18, confirming a weak crystal-field environment for Cr$^{3+}$. Under 430 nm excitation, all samples show a broad NIR band over 650--900 nm with a FWHM of $\sim$101 nm, ascribed to the $^4T_{2g}\rightarrow{}^4A_{2g}$ transition. Fluorescence... More >

The generation of high-brightness white light in laser-illuminated devices is achieved by exciting yellow-green phosphors with a blue laser source. This configuration offers advantages such as high energy density and strong central luminous intensity. Among luminescent materials, LuAG:Ce phosphor ceramics (PCs) are notable for their high thermal stability and luminous output. In this study, LuAG:Ce PCs were produced from co-precipitated monophase nanopowders. The effects of vacuum sintering and air annealing temperatures on their porosity and luminescent properties were investigated. The sample, sintered at 1550°C and subsequently annealed at 1350°C, exhibited 3.5 vol.% porosity, highest r... More >