Study On The Preparation And Properties Of Sr₃Al₂O₆ System Red Luminescent Materials

Alkaline earth aluminates long afterglow materials doped with rare earth ions are high luminescence efficiency, long afterglow time, chemical stability and no radiation pollution, etc., are widely used in various fields. In which yellow-green luminescent materials SrAl2O4 : Eu²⁺, Dy³⁺ and blue-green luminescent materials Sr₄Al₁₄O₂₅ : Eu²⁺,Dy³⁺ has reached industrial production standards, but the matching red aluminates luminescent materials are scarcity, the materials' brightness is not high , their afterglow time is short and the study of red aluminates luminescent materials'luminescence mechanism is not mature.Sr3Al₂O₆ system red luminescent materials were prepared by high-temperature solid state reaction method. By changing the calcination temperature, the added amount of boric acid and the activator content, and doping sulfur ions to study the luminescent properties of Sr3Al₂O₆ system red luminescent materials. The crystal structure of the samples was characterized by X-ray diffraction. The luminescent properties of the samples were characterized by excitation spectra, emission spectra and afterglow decay curves. The result showed that the samples doped with sulfur were mixed-substrate. The main crystal phase of samples was Sr3Al₂O₆, and there was a small amount of impurity phase which was SrS. In the mixed substrate, Eu²⁺ luminescence center was still affecting the luminescent properties With the decrease of Eu²⁺ content, the red shift of emission wavelength for samples was drawn. When Eu²⁺ content was under 0.010, the samples'emission spectra formed of the broadband spectrum, and the emission spectrum peak was about at 612nm. The content of auxiliary activator Dy³⁺ was the auxiliary activator, affected the afterglow properties. When the sample without sulfur ions added a certain amount of boric acid, it calcined at 1200℃for 3h could be formed into a single, complete crystallization of Sr3Al₂O₆ crystal. Its emission spectra had two emission peaks, which were in the vicinity of 595nm and 615nm, and its afterglow properties were better. The content of boric acid didn't only affect the samples'calcination temperature, but also affect the samples'afterglow brightness and afterglow time. Different content of the activator Eu²⁺ and auxiliary activator Dy³⁺ didn't affect the crystal structure of samples. The excitation spectrum of the samples was very broad excitation band in the visible region, the wavelength range was 400⁵30nm.