Structural Confinement toward Giant Enhancement of Red Emission in Mn2+‐Based Phosphors

Abstract Structural confinement effect on a pair of Eu 2+ and Mn 2+ optical centers is developed to realize the greatly enhanced red emission attributed to the 4 T 1 ( 4 G)– 6 A 1 ( 6 S) transition of Mn 2+ ions. Sr 9 Mn 1.26(2) Li 0.24(2) (PO 4− δ ) 7 , when it is doped with Eu 2+ , emerges as a new red‐emitting phosphor, and the intensity dependence of such a red emission on the trace amounts of Eu 2+ doping is quantitatively analyzed with a combined experimental and theoretical methods. The modeling result confirms the validity of this proposed design strategy, and the intrinsic high‐efficient Eu 2+ –Mn 2+ energy transfer process can be elucidated by the structural confinement effect featured as some Sr (Eu) close to Mn atoms. The results can initiate the exploration of Mn 2+ ‐based red phosphors for pc‐white light‐emitting diodes applications, and such a strategy can be easily expanded to other systems, thus opening a new perspective for the development of luminescence materials.