Single matrix white light fluorescent powder for white light LED and preparation method thereof

Abstract

The invention provides single matrix white light fluorescent powder for a white light LED and a preparation method thereof. The chemical composition of the fluorescent powder is Ca2SiO3Cl2: xEu2+, yMn2+, wherein the value ranges of the x and the y are 0.5 to 3 percent. The preparation method comprises the following steps of: dissolving calcium nitrate tetrahydrate and anhydrous calcium chloride into distilled water to obtain solution A; preparing europium nitrate solution B; dissolving the solution B and manganese nitrate tetrahydrate into the solution A together, and stirring the mixture uniformly to obtain solution C; adding anhydrous ethanol into the solution C, stirring the solution uniformly, then adding tetraethoxysilane into the solution, adjusting the pH to between 2 and 3, and stirring the mixture for 1 hour in a 80 DEG C water bath to obtain precursor sol; preparing the precursor sol into wet sol and then preparing the wet sol into dry sol, performing hydrothermal reaction on the dry sol in a reaction kettle, and naturally cooling the reaction product to room temperature after the reaction is finished; and finally, centrifuging and washing the reaction product to obtain a final product. The fluorescent powder prepared by the method emits three bands of 428 nanometers, 500 nanometers and 581 nanometers, and the three bands are superposed to generate white light for emitting; the fluorescent powder has small grain size and uniform distribution, and is like spheroid; and the preparation method is simple and has low energy consumption and low equipment requirement.

Description

【Technical field】 [0001] The invention relates to a fluorescent powder and a preparation method thereof, in particular to a single-matrix white light fluorescent powder for white LEDs and a preparation method thereof. 【Background technique】 [0002] As a new type of solid-state lighting source, white light LED has attracted much attention. Because of its small size, energy saving, long life, no pollution, etc., it has broad application prospects and potential markets, and is regarded as a green lighting source in the 21st century. [0003] At present, there are two main ways to realize white LED through phosphor conversion mechanism: (1) LED+RGB three-color mixed matrix phosphor, the white light produced by this method has high color rendering index and output efficiency, but due to the mixture There are problems of color reabsorption and ratio control, and the lumen efficiency and color reproduction performance are greatly affected. (2) LED + single-matrix phosphor. At pr...

AI Technical Summary

Problems solved by technology

However, due to the lack of red components in the phosphor, the color rendering is poor

At the same time, because the materials that meet the blue light conversion must have strong absorption at 420-470nm, and there are very few materials that meet this condition, which limits the research and development of this type of phosphor

[0004] Recently, a series of single-matrix chlorosilicate phosphors have been synthesized by the solid-state method. This phosphor is a single-matrix white LED phosphor suitable for InGaN tube core excitation. Disadvantages such as large energy consumption, low efficiency, not fine enough powder, easy to mix impurities, and high requirements for equipment

During the preparation of phosphor powder, the particles are easy to agglomerate, and ball milling is required to reduce the particle size, so that the crystal form of the luminous body is destroyed and the luminous performance is reduced.

The particle size of the prepared phosphor is large, there will be component segregation, the particle size distribution is uneven, it is difficult to obtain spherical particles, and there are easy to exist impurity phases, which will reduce the luminous efficiency

If the firing temperature is too high, the sintering will be serious, and the lattice position of the activator will be destroyed during the final grinding, resulting in a decrease in luminous efficiency.

Images