A broadband cyan-emitting NaBa2Al(P2O7)2: Eu2+ phosphor for white light-emitting diodes

White light-emitting diodes (WLEDs) play a crucial role in solid-state lighting technologies. Among the key factors contributing to their performance, the development of high-quality cyan phosphors is critical in achieving excellent color rendering index (CRI) and stable long-term operation. In this study, a cyan-emitting phosphor, NaBa 2 Al(P 2 O 7 ) 2 : x Eu 2+ ( x  = 0.01-0.06), was explored. The material's structures, morphology, optical behavior, and thermal stability were analyzed. Rietveld refinement reveals that the phosphor exhibits high crystallinity and confirms the successful substitution of Eu 2+ ions into Ba 2+ sites within the crystal lattice. Upon excitation at 320 nm, the phosphor emits broad, asymmetric cyan light, with peak intensity occurring at an Eu 2+ concentration of 0.03 achieving internal quantum efficiency (IQE) of 68.9%. Energy transfer and Gaussian fitting analyses show that Eu 2+ ions occupy two distinct crystallographic sites, and concentration quenching is attributed to dipole-dipole interactions. The phosphor retains 77% of its intensity at 425 K, with an activation energy of 0.3173 eV, demonstrating high thermal stability and color consistency. When integrated with a red-emitting phosphor onto a 320 nm UV chip, a white light-emitting diode (WLED) is fabricated, exhibiting a correlated color temperature (CCT) of 5727 K and a color rendering index (CRI) of 95.6. These results highlight this phosphor for applications in advanced white light-emitting diode (WLED) technologies across diverse lighting systems.