Blue fluorescent powder for white-light LED and preparation method thereof

Abstract

The invention relates to blue florescent powder for a white-light LED, belonging to the technical field of rare earth luminescent materials. The blue florescent powder has a chemical formula of: Ca<1-x>SiO3:xEu2+, wherein x is more than 0 and less than 0.2. The preparation method comprises the following steps of: respectively weighing calcium salts, silicic acid, europium nitrate and an appropriate amount of surfactant and fluxing agent according to the stoichiometric ratio in the chemical formula; fully mixing the weighed reactant, the surfactant and an appropriate amount of ligands and then ball-milling, and adding a lubricating agent when in ball-milling; filtering, washing and drying to obtain a precursor; evenly mixing the precursor with the fluxing agent, and then calcining under the reducing atmosphere to obtain the required florescent powder. In the invention, the blue florescent powder for the LED is prepared by adopting a mechanical force solid-phase chemical reaction method, the specific surface area of the reactant is increased by utilizing the shearing force and the impact force generated in the ball-milling process, the contact face and the diffusion speed of the reactant are improved, and the required time in the chemical reaction is shortened. The prepared fluorescent powder has high luminescent strength as well as good color rendering property and stability, and is suitable for LEDs excited by ultraviolet and near ultraviolet.

Description

1. Technical field [0001] The invention belongs to the technical field of rare earth luminescent materials, and in particular relates to a blue fluorescent powder for white LEDs and a preparation method thereof. 2. Background technology [0002] Due to their special electronic layer structure, rare earth elements make the compounds containing rare earth elements exhibit many unique chemical and physical properties, so they are widely used in the fields of optics, electricity, and magnetism. Rare earth luminescent materials are widely used in display, lighting, imaging, and radiation fields due to their narrow emission spectrum band, high color purity, high light conversion efficiency, fluorescence lifetime spanning from nanoseconds to milliseconds up to 6 orders of magnitude, and stable physical and chemical properties. , medical radiology images, coatings and anti-counterfeiting marks and other fields. [0003] In the field of lighting, white light LED is considered to be ...

AI Technical Summary

Problems solved by technology

However, due to the high cost of the sol-gel method, it is difficult to achieve large-scale production; the phosphor powder prepared by the combustion method has low purity and luminescent performance; the spray pyrolysis method has complicated processes and high equipment requirements, making it difficult to industrialize production

Therefore, high-temperature solid-phase method is often used in industry. Although it has the advantages of simple process and low cost, the prepared phosphor still has problems such as phase impurities, poor luminescent performance, and coarse crystal grains.

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