Crystal structure and photo-luminescence of Gd3Ga2(Al3-Si )(O12-N ):Ce3+ phosphors for AC-warm LEDS

Solid solution phosphors Gd3Ga2(Al3-ySiy)(O12-yNy):Ce3+ were synthesized by introducing [Si4++N3–]/[Al3++O2–] co-substitution into the lattice of Gd3Ga2Al3O12:Ce3+. Gd3Ga2Al3O12:Ce3+, characteristic as outstanding light yield (about 50–60 kPh/ MeV), and has been applied in computer tomography (CT), positron emission tomography (PET) nuclear medical detector, et al. With the increase of y value, the coordination environment around Gd3+(Ce3+) shrinked, which were confirmed by combining techniques of structure refinement, energy- dispersive spectrum, elements distribution mapping. As a result, stronger 5d orbital nephelauxetic effect (εc) and bigger 5d energy level splitting (εcfs) were induced. Thus resulting in longer wavelength of excitation and emission from Ce3+, and broadening of emission spectra. The typical sample Gd2.95Ga2Al2.5Si0.5O11.5N0.5:0.05Ce3+ (GGASON0.5:Ce3+) exhibits sufficient red component and persistent luminescence(>10 ms), enables fabrication of warm white light suited for alternating-current (AC) when combined with blue light chip (460 nm).