Li-Solid-Solubilized α-SiAlON Phosphor for High Luminous Efficiency
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Solution Overview
Problem
Li-solid-solubilized α-SiAlON phosphors exhibit a blueshift in fluorescence spectrum, leading to decreased fluorescence intensity compared to Ca-solid-solubilized α-SiAlON phosphors, which limits their luminous efficiency.
Innovation Solution
A Eu-activated Li-solid-solubilized α-SiAlON phosphor with specific lattice constants, oxygen content, and europium content is developed, allowing for emission of orange light with high luminous efficiency by adjusting the composition to optimize fluorescence properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the europium content is increased to enhance fluorescence intensity, then the luminous efficiency improves, but the compositional range for stable structure becomes more restricted
Solution Approach 1:
The patent resolves this contradiction by introducing oxygen content as an additional controllable parameter. By simultaneously optimizing oxygen content (0.1-5 mass%) and europium content (0.1-5 mass%) within defined ranges, the patent expands the stable compositional window, allowing high europium concentrations for high luminous efficiency while maintaining structural stability through the stabilizing effect of oxygen on the α-SiAlON crystal structure
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 phosphor achieves high luminous efficiency with a peak wavelength of 580 to 595 nm when excited by ultraviolet to blue light, surpassing previous luminous efficiency limitations.
Implementation Method 1
a phosphor... that emit orange light, as excited by ultraviolet to blue light
Data Source
Figure 1
AI summary
Provided is a Li-solid-solubilized α-SiAlON phosphor containing Li+ solid-solubilized for stabilization of the structure which is higher in luminous efficiency than any phosphor currently available and a light-emitting element and a lighting device comprising the same. An Eu-activated Li-solid-solubilized a-SiAlON, having a lattice constant a of 0.7820 to 0.7835 nm, a lattice constant c of 0.5645 to 0.5670 nm, an oxygen content of 0.4 to 1.2 mass %, and an europium (Eu) content of 0.3 to 1.2 mass%, and emitting a light having a peak wavelength of 580 to 595 nm in the fluorescence spectrum obtained when it is excited by a monochromatic light having a peak wavelength in the range of 450 to 460 nm.