A high efficient and anti-thermal dual-emission blue-green phosphors for warm white LEDs

A series of broadband blue-green phosphors Rb 0.5+ y Na 1.5− y (Li 3 SiO 4 ) 2 : x Eu 2+ (0 ≤  y  ≤ 0.4, 0.01 ≤  x  ≤ 0.08) were synthesized by the high-temperature solid-state reaction. The powder X-ray diffraction was employed to explore the crystal structural evolution from RbNa 3 (Li 3 SiO 4 ) 4 to RbNa(Li 3 SiO 4 ) 2 with the increasing of Rb + . The spectra show the optimized composition was determined as y  = 0.4. The luminescence, lifetime decay curves and thermal steadily spectra of Rb 0.9 Na 1.1 (Li 3 SiO 4 ) 2 : x Eu 2+ phosphors were investigated in detail. The phosphor of Rb 0.9 Na 1.1 (Li 3 SiO 4 ) 2 :Eu 2+ shows suitable visible spectra (450–550 nm, cover the blue and green regions), excellent thermal quenching (104%@150 °C of the initial integrated intensity at room temperature under 396 nm excitation) and broad excitation spectrum (320–450 nm). Finally, a commercial near-UV LED devices (395 nm) were fabricated with the Rb 0.9 Na 1.1 (Li 3 SiO 4 ) 2 :Eu 2+ phosphor as blue-green and commercial red phosphor CaAlSiN 3 :Eu 2+ with a warm color temperature of 3104 K and a color rendering index of 91.8. This result indicated that Rb 0.9 Na 1.1 (Li 3 SiO 4 ) 2 :Eu 2+ may be a promising blue-green phosphor for indoor lighting.