Effect of Crystallite Size and Crystallinity on Photoluminescence Properties and Energy Transfer of Y 6 MoO 12 :Eu

The phosphors Y 6 MoO 12 :Eu 3+ have been synthesized via citrate complexation method at different calcination temperatures. The evolutions of the crystal structure and the photoluminescence ( PL ) properties were characterized by means of powder X‐ray diffraction ( XRD ), Raman and PL spectra, respectively. It was revealed that a red emission could be obtained via three excitation channels, namely f – f transition of Eu 3+ ions, charge‐transfer transition from O 2 to Eu 3+ , and interband transition ( IBT ) of MoO 6 groups. The PL spectra and their temporal decay character of Eu 3+ ions depended on both crystal structure and excitation channel. The emission reduced with the crystallite size when Eu 3+ ions were excited directly, but the emission evolved in a different model with the host lattices were excited. The effect of grain boundary and other lattice defect on the energy transfer and dissipation within the phosphors were discussed.