J Am Ceram Soc., 2020; 103: 6793– 6800. https://doi.org/10.1111/jace.17304

Broadband near‐infrared (NIR) phosphors have received increasing attention for fabricating phosphor‐converted light‐emitting diodes (pc‐LEDs) as NIR light source. Most of the reported broadband NIR phosphors originate from Cr3+ in weak crystal field environments. Herein, we report a luminescent material, MgAlSiN3:Mn2+ with CaAlSiN3‐type structure, demonstrating that broadband deep‐red‐to‐NIR emission can be achieved via doping Mn2+ into crystallographic sites with strong crystal field in inorganic solids. This phosphor is synthesized via easy‐handle solid‐state reaction, and the optimized sample, (Mg0.93Mn0.07) AlSiN3 shows an emission band with peak at ~754 nm, FWHM of 150 nm, and internal quantum efficiency of 70.1%. The photoluminescence intensity can further be enhanced by co‐doping Eu2+ as sensitizer. This work provides a new strategy for discovering new broadband NIR phosphors using Mn2+ in strong crystal field as luminescence center.