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

Novel YVO4:Eu3+@YPO4 core/shell heteronanostructures with enhanced photoluminescence (PL) are proposed in this paper. They were readily formed by hydrothermal epitaxial growth Of YPO4 onto YVO4:Eu3+ nanocrystals because YPO4 and YVO4 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 YVO4:Eu3+ and YPO4 nanocrystals or YV1-xPxO4:Eu3+ (0 < x < 1) solid solutions, but YVO4:Eu3+@YPO4 core/shell heteronanostructures. The heteronanostructures exhibited much stronger PL than the YVO4:Eu3+ nanocrystals under the same conditions; the optimal heteronanostructures with a YPO4/YVO4:Eu3+ ratio of 1:6 yield a PL intensity 44% higher than that of the YVO4:Eu3+ nanocrystals: The YVO4:Eu3+@YPO4 heteronanostructures have some distinct advantages such as high degree of lattice matching between YVO4 and YPO4. Finally, we discuss the mechanism of their PL enhancement.