Abstract

New white-light-emitting SrSnO₃:Dy³⁺ phosphors were prepared using different concentrations of Dy³⁺ ions via a solid-state reaction. The phase structure, luminescence, and morphological properties of the synthesized phosphors were investigated using X-ray diffraction analysis, fluorescence spectrophotometry, and scanning electron microscopy, respectively. All the synthesized phosphors crystallized in an orthorhombic phase with a major (020) diffraction peak, irrespective of the concentration of Dy³⁺ ions. The excitation spectra were composed of a broad band centered at 298 nm, ascribed to the O^2--Dy³⁺ charge transfer band and five weak bands in the range of 350~500 nm. The emission spectra of SrSnO₃:Dy³⁺ phosphors consisted of three bands centered at 485, 577, and 665 nm, corresponding to the ⁴F_9/2→⁶H_15/2, ⁴F_9/2→⁶H_13/2, and ⁴F_9/2→⁶H_11/2 transitions of Dy³⁺, respectively. As the Dy³⁺ concentration increased from 1 to 15 mol%, the intensities of all the emission bands gradually increased, reached maxima at 15 mol% of Dy³⁺ ions, and then decreased rapidly at 20 mol% due to concentration quenching. The critical distance between neighboring Dy³⁺ ions for concentration quenching was calculated to be 9.4 Å. The optimal white light emission by the SrSnO₃:Dy³⁺ phosphors was obtained when the Dy³⁺ concentration was 15 mol%.

• Keywords: Phosphor, Photoluminescence, Quenching