Red Light Emitting Glass Ceramic Cordierite Phase
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Solution Overview
Problem
Current red light emitting glass ceramics and ceramics suffer from decreased light emitting performance due to the erosion of CaAlSiN3:Eu2+ fluorescent powders during the glass melt and sintering processes, making them unsuitable for high power applications.
Innovation Solution
A red light emitting glass ceramic with a cordierite crystal phase, specifically Mg2Al4Si5O18:Eu2+, is developed using a precursor glass matrix with optimized chemical components and a crystallized thermal treatment process, which enhances light emitting brightness and thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If CaAlSiN3:Eu2+ nitride red fluorescent powder is mixed with low melting point glass powder and melted at high temperature to prepare glass ceramic, then the material can be formed into a glass ceramic structure, but the light emitting performance decreases due to erosion of the fluorescent powder by the glass melt
Solution Approach 1:
The patent introduces an inorganic glass matrix as an intermediary carrier that protects the CaAlSiN3:Eu2+ fluorescent powder from direct contact with the glass melt. The glass matrix serves as a protective medium that allows the fluorescent powder to maintain its structural integrity and optical properties while still enabling the formation of a glass ceramic material through controlled crystallization.
Solution Approach 2:
The patent changes the chemical composition parameters of the glass matrix by incorporating specific ratios of Al2O3 (30-70 mol%), SiO2 (10-80 mol%), and MgO (5-70 mol%) to create a glass system that does not erode the fluorescent powder. This parameter optimization allows the glass ceramic to maintain high light emitting performance while achieving proper material formation.
2Strength
If CaAlSiN3:Eu2+ nitride red fluorescent powder undergoes SPS sintering to obtain ceramic, then the material can be densified, but the light emitting performance decreases due to erosion by sintering aids
Solution Approach 1:
The patent extracts and removes the harmful sintering aids (Si3N4 and SiO2) from the sintering process that cause erosion of the fluorescent powder. Instead, the invention uses a glass matrix formation approach where the glass components are specifically selected to avoid interacting negatively with the CaAlSiN3:Eu2+ powder, thereby maintaining light emitting performance while achieving ceramic densification.
Solution Approach 2:
The patent creates a composite material system consisting of the CaAlSiN3:Eu2+ fluorescent powder embedded in a specially designed inorganic glass matrix. This composite structure combines the advantages of both components: the fluorescent powder provides high light emitting efficiency while the glass matrix provides structural support and protection during processing, achieving both densification and maintained optical performance.
3Ease of manufacture
If traditional organic silica gel is used to package fluorescent powder for laser illumination, then the packaging process is simple, but the material undergoes aging in high power usage due to poor physical and chemical stability
Solution Approach 1:
The patent changes the material composition from organic silica gel to an inorganic glass matrix with specific chemical parameters (Al2O3: 30-70 mol%, SiO2: 10-80 mol%, MgO: 5-70 mol%). This parameter change transforms the packaging material into a thermally and chemically stable inorganic material that can withstand high power laser illumination without aging, while maintaining ease of manufacture through a unified glass ceramic formation process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The red light emitting glass ceramic exhibits excellent light emitting stability and thermal quenching resistance, achieving internal/external quantum efficiencies of up to 94.5%/70.6% and providing superior luminous flux and efficiency compared to existing red light LD apparatuses.
Implementation Method 1
red light emission is originated from emission of divalent europium ions in cordierite crystal phases. The material in the present invention can be excited by light in a waveband of 300-500 nanometers to emit broadband red light with a peak wavelength located in 600-650 nanometers
Implementation Method 2
performing crystallized thermal treatment to prepare a cordierite micro/nano crystal inlaid red light emitting transparent glass ceramic
Data Source
AI summary
The present invention provides a red light emitting glass ceramic and a preparation method thereof, and an LED/LD light emitting device. A2Al4Si5O18:Eu2+ cordierite of the red light emitting glass ceramic capable of realizing blue light excited red light emission is a crystal phase material, wherein A is at least one of Mg, Ca, Sr, Ba and Zn and at least comprises Mg. The present invention particularly provides the red light emitting glass ceramic taking a chemical formula A2Al4Si5O18:Eu2+ as a crystal phase. The present invention further provides a preparation method of the transparent glass ceramic. The glass ceramic comprising the crystal phase, with the chemical formula of Mg2Al4Si5O18:Eu2+, is excited by blue light to emit red light, the internal/external quantum efficiencies reaching up to 94.5%/70.6%, respectively.