Efficient and thermally stable broadband near-infrared emission in a garnet Gd3In2Ga3O12:Cr3+ phosphor. Issue 43 (26th October 2022) - Li, Chaojie
Abstract : A broadband garnet Gd3 In2 Ga3 O12 :Cr 3+ NIR phosphor was successfully developed, and it has an optimized Cr 3+ doping concentration as high as 9 mol%, generating a high quantum yield (85.3%) and ultra-high absorption efficiency (49.1%). Abstract : Compact broadband near-infrared (NIR) light sources generated by phosphor-converted light-emitting diodes (pc-LEDs) have attracted considerable interest in emerging smart NIR spectroscopy applications. However, discovering a highly efficient and thermally stable broadband NIR phosphor still remains a significant challenge. Here, we report a new efficient garnet phosphor, Gd3 In2 Ga3 O12 :Cr 3+, which has a broadband emission peaking at 780 nm with a full-width at half maximum (FWHM) of 124 nm. The optimized Cr 3+ -doping concentration of this material is particularly high (9 mol%), resulting in a high quantum yield and absorption efficiency of 85.3% and 49.1%, respectively. Moreover, 87.7% of the initial emission intensity can be retained when heating up to 150 °C, demonstrating the excellent thermal stability of this material. Fabricating a prototype NIR device by using the as-prepared material in combination with a blue LED chip, an excellent NIR output power (33.7 mW) with a NIR photoelectronic conversion efficiency of 12.0% can be achieved under a 100 mA driving current. These results indicate that the Gd3 In2 Ga3 O12 :Cr 3+ phosphor may have great potential for broadband NIR pc-LED applications.