Sulphide red fluorescent material for white-light LED (light-emitting diode) and preparation method for same

Abstract

The invention discloses a sulphide red fluorescent material for a white-light LED (light-emitting diode) and a preparation method for the same, wherein the general formula of the red fluorescent material is Ca<1-x-y>AxByS: 0.05Eu<2+>, wherein x is greater than 0 and not greater than 0.05, y is greater than 0 and not greater than 0.05, A is one or more of Mg, Sr or Ba, and B is one or more of Al, Ga or In. The red fluorescent material has the advantages of being wide in excitation range, stable in chemical and thermal performances, high in light-emitting efficiency and light-emitting brightness, and the like. The invention further provides a preparation method for the red fluorescent material, comprising the following steps of: step 1, weighing a Ca-containing compound, an A-containing compound, a B-containing compound, an Eu-containing compound and sulphur powder according to the general formula as raw materials, adequately mixing and grinding, and drying to form a mixture; and step 2, placing the mixture in an atmosphere furnace, roasting in a protective atmosphere, cooling and then taking out the mixture, grinding and sieving the mixture to obtain the red fluorescent material. The preparation method has the advantages of easily getting the raw materials, being simple to operate, energy-saving and environment-friendly, and beneficial to industrialized mass production.

Description

technical field [0001] The invention belongs to the technical field of rare earth luminescent materials, and in particular relates to a sulfide red fluorescent material used for warm white LEDs and a preparation method thereof. [0002] Background technique [0003] White LED has the advantages of low power consumption, high luminous efficiency, long service life, energy saving and environmental protection, so it is not only widely used in the field of daily lighting, but also enters the field of display equipment. The technologies for obtaining white LEDs can be divided into two categories, namely: (1) using a mixture of three LED chips emitting red, green, and blue light; (2) using monochromatic (blue or ultraviolet) LED chips to excite appropriate fluorescent light Material. [0004] At present, the white light LED mainly uses the blue light emitted by the blue LED chip to excite YAG: Ce 3+ (coated with Ce 3+ Activated yttrium aluminum garnet, Y 3 al 5 o 12 , refer...

AI Technical Summary

Problems solved by technology

[0005] At present, the white light emitted by white LEDs is all cool white light, and the solubility requirements for dopant ions are also very strict. In order to convert this cold white light into warm white light, the existing technology uses a mixture of two or more types of phosphors. However, due to the different attenuation degrees of different phosphors, the color temperature will continue to change, and usually the color temperature will increase, so that this kind of warm white LED does not have the conditions for an excellent light source

[0006] The host cations of the currently used sulfide red phosphors are mainly alkaline earth metals, which are an important inorganic luminescent host material, and the most widely used is CaS:Eu 2+ Luminescent materials, which have the advantages of easy-to-obtain raw materials, simple preparation process, and low price, but they also have the following disadvantages: 1. The sulfide red fluorescent powder has a strong effect on CO in the atmosphere. 2 、H 2 Components such as O are relatively sensitive, and can undergo slow chemical reactions to gradually weaken or even lose the original conversion luminescence characteristics; 2. Its preparation needs to be carried out under H 2 S or H 2 S and H 2 Under the atmosphere of mixed gas, this process is more complicated, the production cost is high, and H 2 S is highly toxic to the human body

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