Structure and luminescence properties of La6Ba4(SiO4)6F2:Dy3+ phosphor with apatite structure

Abstract

In this study, we investigated the structure, luminescence properties and morphology of La₆Ba₄(SiO₄)₆F₂:Dy³⁺ in detail using X-ray diffraction (XRD), photoluminescence spectroscopy, scanning electron microscopy (SEM) and decay kinetics measurements. The results indicate that La₆Ba₄(SiO₄)₆F₂:Dy³⁺ 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 Dy³⁺ transitions ⁴F_9/2 → ⁶H_15/2 and ⁴F_9/2 → ⁶H_13/2, respectively. These dominant photoluminescence bands are accompanied by a weak red band (670 nm) due to the ⁴F_9/2 → ⁶H_11/2 transition. The emission color of La₆Ba₄(SiO₄)₆F₂:Dy³⁺ phosphors are found to fall in the white light region. The Dy³⁺ optimal dopant concentration in the La₆Ba₄(SiO₄)₆F₂ host was found to be 0.12 (mol). In addition, the phosphors have high thermal stability. Hence, La₆Ba₄(SiO₄)₆F₂:Dy³⁺ may have an application in white light-emitting diodes.