Effects of Sr{sup 2+} substitution on photoluminescence characteristics of Ba{sub 1−x−y}Sr{sub y}ZrSi{sub 3}O{sub 9}:xEu{sup 2+} phosphors

In this work, single-phase Ba{sub 1−x−y}Sr{sub y}ZrSi{sub 3}O{sub 9}:xEu{sup 2+} phosphors were synthesized via the solid-state reaction method. The crystal structure and luminescence properties were investigated using X-ray diffraction and photoluminescence measurements, respectively. An increase of the dopant Sr{sup 2+} increased the emission intensity of the phosphors. The peak intensity of the samples was at y = 0.4 under near-ultraviolet light excitation (397 nm). The wavelength of the emission peaks red-shifts slightly from 477 to 483 nm due to the splitting of the 5d energy level. Sr{sup 2+} ions have a smaller ionic radius than that of Ba{sup 2+} ions, and thus the dopant changes the crystal structure, improving the energy transfer efficiency between luminescence centers. More Eu{sup 2+} solid solubility was found in Ba{sub 0.6−x}Sr{sub 0.4}ZrSi{sub 3}O{sub 9}:xEu{sup 2+} phosphors (10 mol. %) than in the host BaZrSi{sub 3}O{sub 9} (6 mol. %), which enhanced the emission intensity. In addition, the thermal reliability of the phosphors was studied.