Facile synthesis and optical properties of Ce:YAG polycrystalline ceramics with different SiO sub(2) content

Ce:YAG polycrystalline ceramics with different SiO sub(2) content were successfully prepared by a single-step melt-quenching method. The characterization of the resulting polycrystalline ceramics was accomplished by using X-ray powder diffraction, field emission scanning electronic microscopy and energy dispersive X-ray spectroscopy. Then, the optical properties were investigated using a fluorescence spectrometer. It is found that the glass matrix becomes a glassy state more easily, the photoluminescence excitation (PLE) and PL intensity decrease obviously and crystallization of YAG is difficult to generate as the SiO sub(2) content increases. What's more, the intensity of the blue LED decreases and that of the yellow emission band instead increases and saturates at a SiO sub(2) content of 32 mol% in the electroluminescent (EL) spectra. Afterwards, the photoelectric performance was studied by an LED spectrometer. As a consequence, the constructed polycrystalline ceramic based WLED exhibits a high luminous efficiency of 74.44 lm W super(-1), and a correlated color temperature of 5351 K as well as a color rendering index of 75.91, which reveals the prominent feasibility of the present polycrystalline ceramic material in WLED applications.