Narrow‐Band Green‐Emitting Sr₂MgAl₂₂O₃₆:Mn²⁺ Phosphors with Superior Thermal Stability and Wide Color Gamut for Backlighting Display Applications

Abstract The narrow‐band emitting phosphors have been extensively investigated in recent years, with the expectation that a wide color gamut of phosphor‐converted backlighting device could be fabricated. Due to the weak electric–phonon interaction and low structural relaxation caused by the high rigid crystal structure and symmetric coordination environment, Sr₂MgAl₂₂O₃₆:Mn²⁺ (SMAO:Mn²⁺) shows a narrow full‐width at half‐maximum of 26 nm, a high color purity of 81.5%, and a low thermal quenching (82% at 473 K of the initial intensity at 298 K). Using K₂SiF₆:Mn⁴⁺ as the red phosphor, SMAO:Mn²⁺ as the green one, and GaN‐based chip as the blue component, the white light‐emitting diode exhibits a National Television Standard Committee value of 127%. All the results demonstrate that the SMAO:Mn²⁺ phosphor has a promising application in the field of advanced wide‐color‐gamut backlight display, and the establishment of the relationships between the narrow‐band emission and crystal structure can also be applied to design other novel narrow‐band phosphors for backlighting technologies.