Highly Enhanced Photoluminescence from YVO₄:Eu³⁺@YPO₄ Core/Shell Heteronanostructures

Novel YVO 4:Eu 3+ @YPO 4 core/shell heteronanostructures with enhanced photoluminescence (PL) are proposed in this paper. They were readily formed by hydrothermal epitaxial growth of YPO 4 onto YVO 4:Eu 3+ nanocrystals because YPO 4 and YVO 4 have the same crystal structure and similar lattice parameters. Characterizations by means of X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy prove that the as-synthesized products were not a mixture of YVO 4:Eu 3+ and YPO 4 nanocrystals or YV 1− x P x O 4:Eu 3+ (0 < x < 1) solid solutions, but YVO 4:Eu 3+ @YPO 4 core/shell heteronanostructures. The heteronanostructures exhibited much stronger PL than the YVO 4:Eu 3+ nanocrystals under the same conditions; the optimal heteronanostructures with a YPO 4 /YVO 4:Eu 3+ ratio of 1:6 yield a PL intensity 44% higher than that of the YVO 4:Eu 3+ nanocrystals. The YVO 4:Eu 3+ @YPO 4 heteronanostructures have some distinct advantages such as high degree of lattice matching between YVO 4 and YPO 4 . Finally, we discuss the mechanism of their PL enhancement.