Broadband deep‐red‐to‐near‐infrared emission from Mn 2+ in strong crystal‐field of nitride MgAlSiN 3

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 Cr 3+ in weak crystal field environments. Herein, we report a luminescent material, MgAlSiN 3 :Mn 2+ with CaAlSiN 3 ‐type structure, demonstrating that broadband deep‐red‐to‐NIR emission can be achieved via doping Mn 2+ into crystallographic sites with strong crystal field in inorganic solids. This phosphor is synthesized via easy‐handle solid‐state reaction, and the optimized sample, (Mg 0.93 Mn 0.07 ) AlSiN 3 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 Eu 2+ as sensitizer. This work provides a new strategy for discovering new broadband NIR phosphors using Mn 2+ in strong crystal field as luminescence center.