Self-assembly Research And Preparation Of Rare Earth Doped SiO₂ Gel Microspheres

Silica nanometer microspheres doped with rare earth have special optical and electrical properties, and its main properties are closely related to morphology and structure of the light-emitting materials, so the preparation and study of rare-earth doped silica is significant. The base-catalyzed method prepared a good monodispersity silica microspheres, which can be self-assembled silica into three dimensional photonic crystal film. Pure silica has a wide band gap, a low luminous efficiency, the light reduction in catalytic activity and other shortcomings. In order to reduce the defect of materials, the researchers doped nano silica with rare earth and improve the performance of materials. This paper mainly research the preparation of monodisperse pure and doped silica microspheres by base-catalyzed method and the seed growth method and the photonic crystal by self-assembly method and their optical properties.First of all, the pure silica gel microspheres is prepared by the base-catalyzed method, We got good morphology, smooth ball surface, good monodisperse silica microspheres. The effect of experimental conditions on the qualities of microspheres is investigated.Secondly, the rare earth Eu3+ ions doped silica gel microspheres is prepared by the base-catalyzed method and the seed growth method, and optical properties of light-emitting materials and luminescence mechanism is also analyzed. The rare earth doped silica gel microspheres by the base-catalyzed method have many flocculent stuff, is not ideal. The rare earth Eu3+ ion doped silica colloidal microspheres by the seed method have good monodispersity and size uniformity. The result is ideal, its emission spectrum and excitation spectrum is also investigated.Finally, the vertical self-assembled silica crystal film is studied. The effect of experimental conditions including different silica particle size, the concentration of silica microspheres and the angle between slide and liquid surface on the qualities of photonic crystal film is investigated. We got the optimal conditions of self-assembly method.