Low-concentration Ce3+-activated ScCaO(BO3) blue-cyan phosphor with high efficiency toward full-spectrum white LED applications

Near-ultraviolet-pumped white light-emitting diodes (LEDs) based on the combination strategy of traditional RGB phosphors (blue/green/red) or blue/yellow phosphors have the drawback of inadequate color rendering index due to the cyan-gap (480–500 nm) in the emission spectrum. It is quite promising to find efficient cyan-emitting phosphors that can offset the cyan-gap to produce white LEDs with full-spectrum emission. In our work, we synthesized a Ce3+-activated ScCaO(BO3) (SCB:Ce3+) phosphor with a broadband blue-cyan emission. Under near-ultraviolet 396 nm excitation, the optimum SCB:0.005Ce3+ sample shows a blue-cyan emission band with a peak of 473 nm, which is competent for filling the cyan-gap. Meanwhile, the SCB:0.005Ce3+ blue-cyan phosphor possesses a high quantum efficiency (internal quantum efficiency = 66.5%, external quantum efficiency = 38.5%) and weak chromaticity shift (ΔEs = 1.29 × 10−2). We produce white LED devices based on 395 nm LED chips and RGB or blue/yellow/red phosphors strategies. By comparing the performance parameters of white LED devices with or without blue-cyan SCB:0.005Ce3+ phosphor, it is proved that SCB phosphor can offset the cyan gap of commercial RGB phosphors and the cyan emission lack of commercial Y3Al5O12:Ce3+ phosphor. Furthermore, SCB:0.005Ce3+ phosphor can substitute for commercial BaMgAl10O17:Eu2+ phosphor in RGB or blue/yellow/red phosphors combinations. The prepared white LEDs based on SCB:0.005Ce3+ blue-cyan phosphor, green/red or yellow/red phosphors show a lower proportion of high-energy blue light and are suitable for healthy lighting applications.