High color purity aluminate phosphor SryCa1-x-yAl12O19: xEu2+ for lighting and backlight display applications

In the context of the rapid advances in electronic information technology, the advancement of novel high-efficiency narrow-band blue phosphors represents a pivotal step in the advancement of high-quality liquid crystal displays (LCDs), as well as the development of white light-emitting diodes (WLEDs) with a reduced correlated color temperature (CCT). In this study, based on the sensitivity of Eu²⁺ emission to local environment, the alkaline earth aluminate material CaAl₁₂O₁₉ with high structural symmetry was selected as the matrix, and the symmetry of crystal structure was improved by replacing Ca²⁺ with Sr²⁺, the narrow-band emission of the phosphor is realized. The Sr_0.9Ca_0.09Al₁₂O₁₉: 0.01Eu²⁺ (SCAO: Eu²⁺) phosphor exhibited narrow-band emission with the full width at half maximum (FWHM) of 45.76 nm, and the colour purity of up to 95.46 %. Moreover, the internal quantum efficiency (IQE) of SCAO: Eu²⁺ has been demonstrated to reach 81.70 %. In addition, SCAO: Eu²⁺ phosphor, (Ba, Sr)₂SiO₄: Eu²⁺ phosphor, CaAlSiN₃: Eu²⁺ phosphor, and 275 nm UVLED chips were combined to prepare white LED devices exhibiting a low color temperature (3733 K). The three-band LEDs of SCAO: Eu²⁺, β-Sialon: Eu²⁺ and K₂SiF₆: Mn⁴⁺ exhibited a colour gamut covering 84.75 % of the National Television Standards Committee (NTSC) standard. This indicates that the phosphor possesses the characteristics of a highly effective narrow-band blue-light-emitting substance with considerable potential for utilization in lighting and backlighting displays.