Narrow-band cyan and green dual-peak emission Rb2KNa(Li3SiO4)4: Eu2+ phosphor for full-spectrum w-LED: Synthesis, structure, and spectrum regulation

Full-spectrum white LED (w-LED) lighting is primarily achieved through the combination of multiple-color phosphors excited by the chip, and making the development of efficient multi-color phosphors based on single matrix is an excellent choice for full-spectrum w-LED. In this paper, a series of Rb2KNa(Li3SiO4)(4): xEu(2+) (0.1 % <= x <= 15 %) phosphors were successfully synthesized via high-temperature solid-state reaction with varied Eu2+ concentration. At low doping concentration, the Eu2+ ions exhibit primarily green emission at 530 nm in the phosphor. However, as the doping concentration of Eu2+ ions increase, the emission spectrum undergoes a significant transformation. A cyan emission occurs at 478 nm, resulting in the spectral conversion from a green single-peak emission to a dual-peak emission of cyan and green. The spectral conversion is attributed to the changes in the positioning of Eu2+ ions within the crystal lattice. The obtained phosphors demonstrate excellent thermal stability and can be utilized in w-LED devices. After encapsulation with a blue LED chip, it achieves a color rendering index of 91.8 and a correlated color temperature of 4085 K, showcasing its significant application value in the field of full-spectrum w-LED.