Germanate Luminescence Material for High Color Rendering LED Lighting
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Solution Overview
Problem
Current fluorescent materials used in LED lighting have limitations such as low color rendering and high color temperature, making them unsuitable for achieving white and multicolor lighting effectively, particularly when excited by UV and blue light sources.
Innovation Solution
Development of a germanate luminescence material with specific rare earth ion doping, such as Ce, Tm, Ho, Sm, Tb, Eu, and Dy, in the form of (Y1-xLnx)2GeO5, which is prepared through a high-temperature solid phase method involving sintering of raw materials at 1300-1500°C, allowing for the emission of red, green, and blue light when excited by UV and blue light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If Ce-activated rare earth garnet yellow fluorescent powder (YAG:Ce3+ or TAG:Ce3+) is used in LED lighting, then the yellow light emission is achieved, but the color rendering is poor and color temperature is high
Solution Approach 1:
The patent segments the fluorescent material into multiple rare earth ion components (Ce3+, Tm3+, Ho3+, Sm3+, Tb3+, Eu3+, Dy3+) that emit different colors (yellow, blue, green, red, green, red, yellow) simultaneously within a single host lattice (Y2GeO5). This segmentation of color emission functions resolves the contradiction by providing full-spectrum coverage for better color rendering while maintaining the yellow emission component for LED compatibility.
Solution Approach 2:
The patent creates a composite fluorescent material by doping multiple rare earth ions into the Y2GeO5 host lattice to form (Y1-xLnx)2GeO5 compounds. This composite approach combines the advantages of different rare earth emissions (yellow from Ce, blue from Tm, green from Tb, red from Eu and Sm) to achieve both strong yellow emission for LED excitation and improved color rendering through multi-color emission, directly resolving the technical contradiction.
2Device complexity
If conventional fluorescent materials are used for white light LED, then the structure is simple, but the application range is limited and they will be replaced by UV-LED with tricolor fluorescent powder
Solution Approach 1:
The patent makes the Y2GeO5 host lattice universal by demonstrating its ability to accommodate multiple types of rare earth ions (Ce, Tm, Ho, Sm, Tb, Eu, Dy) simultaneously, enabling a single material system to function for both current yellow LED applications and future UV-LED tricolor applications. This multi-functionality resolves the contradiction by maintaining structural simplicity while dramatically expanding adaptability across different LED architectures.
Solution Approach 2:
The patent utilizes parameter changes by adjusting the doping concentration ratios of different rare earth ions (represented by the parameter x in (Y1-xLnx)2GeO5) to optimize emission characteristics. By varying these compositional parameters, the material can be tuned for different lighting applications (white light, multicolor, UV-LED conversion), thereby expanding application range while maintaining the simple single-phase structure.
3Reliability
If high temperature sintering (1300-1500°C) is used to prepare germanate luminescence material, then the luminescent property is enhanced, but the energy consumption increases
Solution Approach 1:
The patent optimizes the sintering temperature parameter within a specific range (1300-1500°C) to achieve the best balance between luminescent property enhancement and energy consumption. By precisely controlling this thermal parameter along with sintering time (6-24 hours), the material achieves stable and enhanced luminescence without excessive energy waste, resolving the contradiction through parameter optimization.
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 germanate luminescence material exhibits enhanced luminescent properties, improving color rendering and reducing color temperature, enabling the production of high-quality, stable fluorescent powders suitable for industrial applications in multicolor LED lighting.
Implementation Method 1
the germanate luminescence material exhibits enhanced luminescent properties, improving color rendering and reducing color temperature, enabling the production of high-quality, stable fluorescent powders suitable for industrial applications in multicolor LED lighting
Implementation Method 2
grinding the raw material uniformly, and then sintering the raw material at 1300-1500° C. for 6-24 h
Data Source
AI summary
A kind of germanate luminescence material and its preparation. The germanate luminescence material is a compound of following formula: (Y1-xLnx)2GeO5, or Y in the said formula is partly or entirely substituted by at least one of Gd, Lu, Sc and La, and x is 0<x≦0.3, and Ln is one of Ce, Tm, Ho, Sm, Tb, Eu and Dy. The preparation is grinding the raw material, and then sintering at 1300-1500° C. for 6-24 h, and cooling the sintered product to room temperature, and obtaining the germanate luminescence material.