Cyan-emitting Ba3Y2B6O15:Ce3+,Tb3+ phosphor: A potential color converter for near-UV-excited white LEDs

A series of Ce3+ and Tb3+ ions codoped Ba3Y2B6O15 (BYBO) color tunable phosphors were successfully synthesized by high temperature solid state reaction. X-ray diffraction (XRD) patterns, crystal structure, excitation and emission spectra, CIE coordinates, thermal stability and internal quantum efficiency of these phosphors were systematically studied. An efficient cyan light was achieved in BYBO:0.03Ce(3+), 0.3Tb(3+) phosphor, and the energy transfer mechanism from Ce3+ to Tb3+ ions was discussed in detail. Through coating BYBO:0.03Ce(3+), 0.3Tb(3+) cyan-emitting phosphors with commercial CaAlSiN3:Eu2+ red phosphors on a 365 nm near-ultraviolet (NUV) LED chip, a white light-emitting diode (WLED) device with low correlated color temperature (4850 K), good color rendering index (92), and CIE chromaticity coordinates (0.3478, 0.3409) was fabricated. The results identified that BYBO:0.03Ce(3+), 0.3Tb(3+) may be used as a cyan-emitting phosphor for NUV-pumped WLED application.