Near-Infrared LuCa2ScZrGa2GeO12:Cr3+ Garnet Phosphor with Ultra-broadband Emission for NIR LED Applications

A series of Cr3+-doped LuCa2ScZrGa2GeO12 phosphors with broadbandemissions were synthesizedby the high-temperature solid-state method for NIR pc-LED applications. Near-infrared phosphor-converted light-emitting diodes(NIR pc-LEDs),as a new generation of NIR lighting sources, have wide prospects inthe areas of food analysis and biological and night vision imaging.Nevertheless, NIR phosphors are still limited by short-wave and narrowbandemissions as well as low efficiency. Herein, a series of NIR phosphors,LuCa2ScZrGa2GeO12:Cr3+ (LCSZGG:Cr3+), with broadband emissions have been developedand first reported. At 456 nm excitation, the optimized LCSZGG:0.005Cr(3+) phosphor represents an ultra-broadband emission within therange of 650-1100 nm, peaking near 815 nm with a full widthat half maximum of 166 nm. Furthermore, the LCSZGG:0.005Cr(3+) phosphor possesses good internal quantum efficiency of 68.75%, andits integrated emission intensity at 423 K still retains about 64.17%of that at room temperature. By combining the optimized sample witha blue chip, a NIR pc-LED device is fabricated, which has an excellentNIR output power of 37.88 mW with an NIR photoelectric conversionefficiency of 12.44% under a 100 mA driving current. The aforementionedresults demonstrate that these LCSZGG:Cr3+ broadband NIRphosphors are expected as NIR light sources.