Enhanced thermal stability of broadband NIR phosphors Ca3.3Mg0.7ZrGe3O12:Cr3+ for pc-LEDs

Near-infrared phosphor-converted light-emitting diodes (NIR pc-LEDs) are playing an increasingly important role in the spectroscopy technology fields. Developing high-performance NIR-emitting phosphors is of immense significance for advancing NIR pc-LEDs. Herein, the approach of cationic substitution of Ca2+ by Mg2+ was designed in Ca4ZrGe3O12:Cr3+. Remarkably enhanced NIR emission and strikingly improved thermal stability are realized. The luminescence intensity at 423 K compared with that of room temperature ascends from 45.67 % to 72.81 %. Moreover, the representative sample was assembled to a NIR pc-LED with favorable output power and photoelectric conversion efficiency by combining a commercial 470 nm blue chip. The packaged LED demonstrates the feasibility of practical applications in night vision, biological imaging, and fruit detection. The above findings verify the potential prospect of Ca4-xMgxZrGe3O12:Cr3+ phosphor for the utilizations in NIR light sources.