Fluorescent glass with gradient refractive index and preparation method thereof

Abstract

The invention discloses fluorescent glass with a gradient refractive index. The fluorescent glass comprises a glass substrate and a plurality of fluorescent glass coatings on the surface of the glass substrate, wherein the refractive index of the innermost fluorescent glass coating is more than the refractive index of the glass substrate, and the refractive index is increased layer by layer from inside to outside, so as to form the gradient refractive index, wherein modified glass powder and fluorescent powder are taken as raw materials and are prepared into each layer of fluorescent glass coating on the basis of multilayer silk screen printing and low-temperature sintering techniques. The fluorescent glass with the gradient refractive index is mainly used for packaging a high-power white light LED (Light Emitting Diode), and a gradient refractive index structure is adopted for reducing the total reflection and Fresnel reflection of light emitted from an LED chip on a packaging interface because of larger change in refractive index, so that the luminous efficiency can be increased; and the acquired fluorescent glass coatings have excellent luminescent properties of crystal materials and high thermal stability of glass materials, so that the problems of poor durability and color stability of the present white light LED can be effectively solved.

Description

technical field [0001] The invention belongs to the fields of fluorescent glass preparation and LED application materials, and in particular relates to a gradient refractive index fluorescent glass coating for high-power white LED packaging and a preparation method thereof. Background technique [0002] White light LED has the characteristics of high efficiency, energy saving, green environmental protection, small size, and long life, so it has become a general trend to enter the lighting field. It will become the fourth-generation lighting source surpassing incandescent lamps, sodium lamps and fluorescent lamps in the history of human lighting. As the most promising electric light source in the 21st century, the development of white LED lighting technology will have a profound impact on a country's energy strategy and environmental protection strategy. [0003] At present, improving the light extraction efficiency of LEDs has always been a hot issue. For the traditional LE...

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Problems solved by technology

However, it is difficult to prepare such glass flakes due to the poor dispersion uniformity of nanoparticles in the glass powder.

In addition, Sun Yunan et al. used borate glass for ion exchange to obtain gradient refractive index glass, but due to the limitation of the diffusion depth of cations in the glass, it is only suitable for small-sized components, and the obtained refractive index gradient is also very limited.

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