Correlation of photoluminescence of (La, Ln) PO4:Eu3+ (Ln = Gd and Y) phosphors with their crystal structures

Eu3+-doped (La, Ln) PO4 (Ln = Gd and Y) phosphors were prepared by a facile co-precipitation method. Their structures and luminescent properties under UV excitation were investigated. Structural characterization of the nanostructured luminescence material was carried out with X-ray powder diffraction analysis. Scanning electron microscopy was carried out to understand the surface morphological features and grain sizes with 50-100 nm. It is found that (La, Gd) PO4:Eu3+ phosphors have the same crystal structure as LaPO4:Eu3+, which is monoclinic with a little different lattice parameters. In the case of (La, Y) PO4:Eu3+ phosphors, however, the gradual change from monoclinic to tetragonal structure of host lattice was observed, as the amount of Y ion increased. From the photoluminescence spectra for (La, Ln) PO4:Eu3+ (Ln = Gd and Y), the emission transition D-5(0) -> F-7(1) has been found to be more prominent over the normal red emission transition D-5(0) -> F-7(2). Furthermore, the size influence on the products was discussed. It was observed that the spectral features possess sharp and bright emission for potential applications on the