Cr<3+>-doped aluminum-rich aluminum magnesium spinel fluorescent transparent ceramic and preparation method thereof

Abstract

The invention relates to a Cr<3+>-doped aluminum-rich aluminum magnesium spinel fluorescent transparent ceramic and a preparation method thereof, wherein the Cr<3+>-doped aluminum-rich aluminum magnesium spinel fluorescent transparent ceramic has a single-phase aluminum magnesium spinel structure, the structure formula is Mg8-3yAl16-2x+2yCr2x[square]yO32, x is more than or equal to 0.0005 and is less than or equal to 0.01, y is more than or equal to 0.3 and is less than or equal to 1.5, and the [square] is the vacancy number of the octahedron. The preparation method comprises: preparing MgAl2O4:Cr<3+> single-phase ceramic powder through low-temperature pre-sintering; pre-firing by using the MgAl2O4:Cr<3+> and Al2O3 powder as raw materials to obtain a MgAl2O4:Cr<3+> / Al2O3 composite phase sintering body with compact and closed gas pores, wherein the MgAl2O4:Cr<3+> / Al2O3 composite phase sintering body has the same chemical position as a aluminum-rich aluminum magnesium spinel fluorescenttransparent ceramic; and carrying out hot isostatic pressing treatment at a temperature of more than a single-phase aluminum-rich aluminum magnesium spinel forming temperature, and during the treatment, further carrying out a solid phase reaction on MgAl2O4 and Al2O3 so as to prepare the Cr<3+>-doped aluminum-rich aluminum magnesium spinel fluorescent transparent ceramic. According to the presentinvention, under the premise of the assurance of the transmissivity of the transparent ceramic, the fluorescent property of the material is regulated by changing the base body so as to improve the color rendering property of the material; and by using the fluorescent transparent ceramic block material to replace the organic glue to encapsulate the powder, the heat dissipating and light efficiencyconversion problem can be easily solved, and the stability of LED devices can be expected to be improved.

Description

technical field [0001] The invention relates to a method for preparing ceramic materials, in particular to a method for preparing chromium-doped aluminum-rich magnesium-aluminum spinel fluorescent transparent ceramics, which belongs to the field of fluorescent transparent block material preparation. Background technique [0002] As the application of white light emitting diodes (Light Emitting Diode, LED) in the field of lighting continues to expand, it has been widely used in fields such as display, transportation, and automobiles. However, as the power of LED chips continues to increase and LED light-emitting modules are highly integrated, the reliability and stability of high-power white LED products have become a bottleneck restricting product development. At present, the most widely used packaging method for white light LEDs is to coat the chip with phosphor powder and a layer of transparent adhesive layer (a mixture of epoxy resin and silica gel) with a relatively high...

AI Technical Summary

Problems solved by technology

However, most of these white LEDs use phosphors of different substrates, and the luminous efficiency and stability of red phosphors cannot be compared with yellow and green phosphors, which will still affect the luminous efficiency of white LEDs.

Therefore, no matter what method is currently used, the lack of red fluorescent components restricts white LEDs from obtaining better color temperature and color rendering.

Images