Luminescent properties of Eu3+-doped glass ceramics containing BaGdF5 nanocrystals under NUV-excitation for W-LEDs

Eu3+ doped transparent glass ceramics containing BaGdF5 nanocrystals were successfully fabricated by melt-quenching technique, and their structural and luminous properties were investigated. X-ray diffraction (XRD) and transmission electron microscopy(TEM) proved the existence of BaGdF5 nanocrystals in the transparent glass ceramics, which plays an important role in improvement the luminescent properties. The excitation spectra showed that the glass and glass ceramics could be effectively excited by near ultraviolet (NUV) light. Intense red emission located at 611 nm and longer lifetimes observed in glass ceramics are attributed to the incorporation of Eu3+ ions into BaGdF5 nanocrystals with lower phonon energy. The CIE chromaticity coordinates of glass ceramics (GC610) were calculated as (x=0.625, y=0.374), which was close to the NTSC standard values for red (x=0.67, y=0.33). The results suggest that the glass ceramics may be used as potential red phosphors under near ultraviolet (NUV) light excitation for white light-emitting diodes (W-LEDs).