Synthesis and luminescent properties of nanoparticles LaSrAl3O7:Eu, Tb

Phosphors of nanoparticles LaSrAl3O7:RE3+(REEu, Tb) have been prepared by a sol–gel method. The structure and luminescent properties of LaSrAl3O7:Eu3+ and LaSrAl3O7:Tb3+ phosphors were characterized by X-ray diffraction and atomic force microscopy (AFM), photoluminescence excitation and emission spectra were utilized. From X-ray diffraction (XRD) patterns, it is indicated that the phosphor LaSrAl3O7 forms without impurity phase at 900 °C. From atomic force microscopy (AFM) images, it is shown that the crystal size of the phosphores are about 60–80 nm. Upon excitation with UV irradiation, it is shown that there is a strong emission at around 617 nm corresponding to the forced electric dipole 5D0–7F2 transition of Eu3+, and at around 545 nm corresponding to the 5D4–7F5 transition of Tb3+. The dependence of photoluminescence intensity on Eu3+(or Tb3+) concentration and annealing temperature were also studied in detail.