Structure and luminescence properties of La 6 Ba 4 (SiO 4 ) 6 F 2 :Dy 3+ phosphor with apatite structure.

In this study, we investigated the structure, luminescence properties and morphology of La 6 Ba 4 (SiO 4 ) 6 F 2 :Dy 3+ in detail using X-ray diffraction (XRD), photoluminescence spectroscopy, scanning electron microscopy (SEM) and decay kinetics measurements. The results indicate that La 6 Ba 4 (SiO 4 ) 6 F 2 :Dy 3+ was well crystallized, and its structure is of apatite-type and belongs to the hexagonal system. The prepared samples exhibit two intense characteristic bands in the blue (484 nm) and yellow (579 nm) spectral ranges corresponding to the Dy 3+ transitions 4 F 9/2 → 6 H 15/2 and 4 F 9/2 → 6 H 13/2 , respectively. These dominant photoluminescence bands are accompanied by a weak red band (670 nm) due to the 4 F 9/2 → 6 H 11/2 transition. The emission color of La 6 Ba 4 (SiO 4 ) 6 F 2 :Dy 3+ phosphors are found to fall in the white light region. The Dy 3+ optimal dopant concentration in the La 6 Ba 4 (SiO 4 ) 6 F 2 host was found to be 0.12 (mol). In addition, the phosphors have high thermal stability. Hence, La 6 Ba 4 (SiO 4 ) 6 F 2 :Dy 3+ may have an application in white light-emitting diodes.