Transparent ceramic for high brightness white light-emitting diode and preparation method thereof

Abstract

The invention discloses transparent ceramic for the high brightness white light-emitting diode (LED) and a preparation method thereof. The chemical formula of the transparent ceramic is (Y3-x-y-zCexLiyRz)(Al5-nMn)O12, wherein R is at least one of La, Pr, Sm, Gd, Tb and Dy; M is at least one of Sc, Ti, V, Cr and Mn; and x is larger than or equal to 0.003 and less than or equal to 0.06, y is larger than or equal to 0.003 and less than or equal to 0.06, z is larger than or equal to 0 and less than or equal to 0.75, and n is larger than or equal to 0 and less than or equal to 0.75. The raw material powder prepared by the solid-phase ball milling method or wet chemical method is used for preparing the transparent ceramic which has the advantages of fine crystal particle, uniform size and ultralow porosity through moulding, cold isostatic pressing and vacuum sintering. The transparent ceramic has the characteristics of high transmissivity and thermal conductivity, good chemical stability and thermal stability and high fluorescence conversion efficiency.

Description

technical field [0001] The invention relates to transparent ceramics, in particular to a transparent ceramic used for high-brightness white light-emitting diodes (hereinafter referred to as LEDs) and a preparation method thereof, which belongs to the technical field of preparation of special optical functional ceramics. Background technique [0002] Compared with traditional lighting sources, white LEDs have the characteristics of small size, low energy consumption, fast response, long life, and no pollution. The huge market prospect is generally regarded as a new light source to replace traditional lighting devices, and has been highly valued at home and abroad. Especially in the context of increasingly prominent global energy conservation and environmental protection issues, the development of high-efficiency and energy-saving semiconductor solid-state lighting is of great significance. [0003] At present, the most common method of making white LEDs is to use high-efficie...

AI Technical Summary

Problems solved by technology

However, for high-power and high-brightness white LEDs, there are serious problems in using traditional phosphors as conversion materials: the blue LED chip will continue to heat up when it is lit with a large injection current, and the epoxy resin or silicone shell cannot meet the heat dissipation requirements. The temperature of the LED chip will rise and the luminous efficiency will decrease; on the other hand, the conversion efficiency of the phosphor will decrease when the temperature rises, and the epoxy resin or silicone shell will accelerate aging under the accumulation of continuous heat, so that the conversion efficiency of the phosphor will also decrease. Decrease, resulting in thermal-induced light decay of high-brightness white LEDs, affecting its practicability

At present, transparent ceramics using YAG:Ce system (including doped Gd, Pr, Sm, Dy, etc.) can be used as conversion materials for white light LEDs, but their conversion efficiency is still far behind that of traditional YAG:Ce system phosphors.

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