Method for preparing alkaline-earth silicate fluorescent powder activated by rare earth elements

Abstract

The invention discloses a method for preparing alkaline-earth silicate fluorescent powder activated by rare earth elements. The chemical expression formula of the alkaline-earth silicate fluorescent powder is M2-xSiO4:xRe, wherein M is any one or combination of Ca, Mg, Zn, Sr and Ba; Re is one or combination of Ce, Tb, Eu, Dy and Sm; and x is less than or equal to 0.4. The method comprises the following steps: weighting soluble salt of the elements according to stoichiometric proportion; introducing Si element by tetraethoxy silane (TEOS), and preparing various compositions into homogeneous solution; and introducing a microwave oven drying method in a gel preparing process to prepare an alkaline-earth silicate fluorescent material. The method disclosed by the invention has low energy consumption and short cycle; and the prepared product has good dispersibility, small grain diameter and concentrated granularity distribution, is similar to a sphere, optimizes the structural performance of the material, provides convenient condition for LED encapsulation to have even and compact coating, and has active promoting function of improving LED performance.

Description

technical field [0001] The invention belongs to the technical field of fluorescent powder for LEDs, and relates to a preparation method of alkaline earth silicate fluorescent powder activated by rare earth elements. Background technique [0002] Alkaline earth silicates activated by rare earth elements, as an important class of luminescent materials, have good chemical and thermal stability. They have a wide excitation spectrum and can be excited by ultraviolet, near ultraviolet, and blue light to exhibit high luminous efficiency. The emission spectrum covers Larger wavelength range, so it becomes an important source of LED phosphor materials. For example, Park et al prepared europium-activated Sr by solid-phase method 2 SiO 4 Matched with an InGaN chip to produce white light. [0003] With the continuous progress and wide application of LED (Light Emitting Diode) technology, high-power and high-efficiency LEDs that may become the next generation of lighting sources have ...

AI Technical Summary

Problems solved by technology

The industry generally adopts the solid-phase method to synthesize phosphors. Although the method is simple and easy, there are many reaction components, the mixing cannot be uniform enough, the reaction temperature is high and energy consumption is high, and the product needs ball milling, which will cause crystal damage and may introduce impurities. luminous intensity etc.

The co-precipitation method is difficult to precipitate at the same time because of the different precipitation conditions of each component, and it is easy to affect the luminescent performance due to uneven doping of the activator

Due to the existence of different temperature zones in the combustion method, there are differences in the synthesis temperature of the product, which may easily cause uneven particle size distribution of the product

The sol-gel method has the advantages of low energy consumption, uniform particle size distribution, small particle size, and good dispersion of the obtained product, but its excessively long production cycle limits its promotion in industrial production

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