Preparation And Luminescence Properties Research Of Blue-Green Material Sr₄Al₁₄O₂₅with Long Afterglow

Alkaline earth aluminates have very stable spinel structure, which is superior to the traditional sulfide phosphores as persistent materials. Aluminum alkaline acid salt material is a new type of energy saving, high efficiency, stable, environmental protection luminescent material.Aluminum acid luminescent powders are widely used in the printing industry, plastic industry, coating industry, glass enamel, textile industry, etc. A typical example of which is the green-yellow SrAl2O4:Eu2+, Dy3+long afterglow phosphorescent material developed in the1990s. In recent years, a new type of blue-green long afterglow phosphorescent material Sr4Al14O25: Eu2+, Dy3+is much favour, because of its good light, heat stability, chemical stability, slow afterglow attenuation, strong luminous intensity, no radiation, non-toxic pollution-free advantages. However, the long afterglow phosphorescent powder is still in laboratory studying period, less application. The main reason is that the afterglow time is not long enough, the luminous property and preparation technology also need to be further improved to meet the higher life standard and production requirements. Therefore, it is necessary to do deep research of the Sr4Al14O25:Eu2+, Dy3+luminous powder, looking for and synthesising blue-green long afterglow phosphorescent material which has he best luminous property.In this paper, using high temperature solid phase reaction method makes Sr4Al14O25:Eu2+, Dy3+long afterglow phosphorescent powder. This method has the mature craft, convenient control, and the materials can form good crystal structure. Using carbon powder as reducing agent, replaced the traditional process not safe and not economic mix of reducing gas. After the powder is prepared, we use the X ray diffraction, fluorescence spectrometer, scanning electron microscopy test analysis means to analyse the crystal structure, fluorescence spectrum, persistence characteristic, morphology characteristics and composition characteristics, and study the relationship among synthesis temperature, Eu doping density, Dy doping density, boric acid additives doping density and other effect factors of the Sr4Al14O25:Eu2+, Dy3+luminous property, and then find the best synthetic process parameters.This paper is mainly composed by the following five parts:Chapter1:This chapter briefly introduces the basic concept of luminescence materials, the history of long afterglow phosphorescent materials, development situation, the application, preparation method and the mechanism of long afterglow phosphorescent materials. At last, it introduces the theme ideas and the main research content.Chapter2:This chapter mainly introduces the experiment design and research methods, and the preparation, test instruments.Chapter3:Using carbon powder as reducing agent, the Sr4Al14O25:Eu2+, Dy3+blue-green long afterglow phosphorescent powders are prepared by the high temperature solid phase reaction method, and study the influence such as synthesis temperature, Eu doping density, Dy doping density and boric acid additives doping density on the luminous property of the Sr4Al14O25:Eu2+Dy3+phosphorescent powders. Experiments show that, when the synthesis temperature is1400℃, H3BO3content is10%, Eu2O3content is2%and Dy2O3content is1%, the material has the best luminous property, and afterglow time lasts more than24hours.Chapter4:In this chapter, the long afterglow phosphorescent mechanism of luminous materials is discussed thoroughly, and combined with references and the analysis of the test results, an improved Sr4Al14O25:Eu2+, Dy3+luminous mechanism model is made.Chapter5:This chapter is a brief summary of the whole paper.