Development of Eu ²⁺ ‐Doped UCr ₄ C ₄ ‐Type Phosphors Toward Advanced Display Applications

Abstract Display technology is an indispensable cornerstone of the modern information era, where phosphors have been playing an important role in the display application. Eu 2+ ‐doped UCr 4 C 4 ‐type phosphors are transformative materials for next‐generation displays, offering narrow emission bands, high quantum efficiency, and thermal stability. Their rigid crystal structure, derived from the UCr 4 C 4 mineral framework, optimizes Eu 2 ⁺ luminescence. Over the past decade, substantial advancements have been achieved in developing nitride, oxide, and oxynitride variants with tunable emissions across the visible spectrum. Solid‐solution approaches enable precise spectral control to meet diverse application demands. However, poor moisture resistance limits practical use due to rapid degradation in humid conditions. Encapsulation methods, including hydrophobic coatings, inorganic layers, hybrid “Soft + Hard” systems, along with intrinsic material modifications (composition substitution) have been explored to enhance stability without compromising luminescent performance. These phosphors show exceptional potential in high‐resolution, low‐power, and high‐brightness displays. This review summarizes their development, structural characteristics, spectral‐tuning strategies, moisture‐resistance improvements, and applications, while outlining future research directions to bridge fundamental studies and practical implementation in advanced display technologies.