Luminescent properties of SrLi₃AlO₄:Eu²⁺ phosphor with two narrow-band emissions discovered by the single-particle-diagnosis approach

Phosphors exhibiting narrow-band emission are key materials for LED backlights in next-generation liquid crystal displays (LCDs) that require high color reproducibility. We successfully realized a hypothetical composition, SrLi3AlO4 (SLAO):Eu2+, which is expected to exhibit narrow-band emission, by inspiring from reported SrLiAl3N4 (SLAN):Eu2+. Using a single-particle-diagnosis approach, SLAO was selectively extracted from calcined powder mixture involving multiple phases, followed by crystal structure analysis and optical property characterization. SLAO:Eu has a similar cubic structure as SLAN, while it shows narrow-band yellow-green emission at 521 nm and 567 nm with full widths at half maximum (FWHM) of 39 nm and 40 nm, respectively. The emission characteristic is comparable with that of quantum dots, demonstrating (i) the feasibility of material design based on the coordination environment similarities and (ii) the resultant SLAO:Eu as a promising phosphor for the next-generation display applications. Discovery of unreported SrLi3AlO4:Eu2+ with two narrow emission bands via single-particle-diagnosis, demonstrating an innovative approach for designing novel high-performance phosphors