Theoretical Prediction‐Assisted Synthesis of Narrow‐Band Red‐Emitting Fluoride Phosphors with High Film‐Forming Ability for Mini Light‐Emitting Diode Displays

ABSTRACT Mn 4+ ‐activated narrow‐band red‐emitting fluoride phosphors are crucial for achieving ultra‐wide color gamut displays. However, simultaneously realizing high luminescence efficiency, short fluorescence lifetime, and facile film‐forming capability in such materials remains a significant challenge. Herein, we propose a theoretical crystal structure prediction‐guided synthesis strategy to discover new Mn 4+ ‐doped fluorides with targeted luminescent properties. Guided by theoretical predictions, we achieve the synthesis of a novel organic‐inorganic hybrid fluoride (TMSO) 2 GeF 6 :Mn 4+ (TMSOGFM) incorporating trimethyl sulfoxide (TMSO) + as the organic building block, which exhibits high luminescence efficiency, with high internal and external quantum yields of 83.4% and 51.7%, respectively, and a short fluorescence lifetime of 4.22 ms, as well as high film‐forming ability. Based on the TMSOGFM, a 7‐inch Mini light‐emitting diode (Mini‐LED) display prototype is successfully fabricated, featuring a wide color gamut reaching approximately 119.7% of the National Television System Committee (NTSC) standard, demonstrating the great potential of the theoretically predicted TMSOGFM for display applications. This work represents the first successful case of “prediction‐to‐synthesis” for Mn 4+ ‐activated fluoride phosphors and provides a new pathway for the rational design of luminescent materials.