Ce-Doped Phosphor Powder Composition for Stronger Blue-Light Fluorescence
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Solution Overview
Problem
The phosphor disclosed in Patent Document 1 has room for improvement in terms of fluorescence peak intensity when irradiated with blue light.
Innovation Solution
A phosphor powder with a general formula Mx(Si, Al)2(N, O)3±y, where M is Li and one or more alkaline earth metal elements, and part of M is substituted with Ce, with a Si/Al atomic ratio of 1.5 to 6, O/N atomic ratio of 0 to 0.1, 5 to 50 mol % Li, and 0.5 to 10 mol % Ce, and a total content of Cr, Fe, and Ni elements limited to 20 ppm or less, is developed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the phosphor composition is modified to improve fluorescence peak intensity, then the fluorescence performance is enhanced, but the manufacturing precision and composition control become more difficult
Solution Approach 1:
The patent applies parameter changes by precisely controlling the chemical composition parameters of the phosphor material. Specifically, it defines narrow ranges for M content (0.52≤x≤0.9), O/N ratio (0≤O/N≤0.1), Si/Al ratio (1.5≤Si/Al≤6), and restricts impurity levels (Cr+Fe+Ni≤20 ppm). This systematic parameter optimization resolves the contradiction by establishing precise compositional specifications that achieve high fluorescence intensity while providing clear manufacturing control criteria.
2Illumination intensity
If the O/N atomic ratio is increased to improve fluorescence intensity, then the light emission performance is enhanced, but the chemical stability of the phosphor may deteriorate
Solution Approach 1:
The patent resolves this contradiction by optimizing the O/N atomic ratio within a specific range (0≤O/N≤0.1). This parameter control allows the phosphor to achieve high fluorescence intensity through increased O/N ratio while maintaining chemical stability by not exceeding the upper limit of 0.1, thus balancing performance enhancement with material stability.
3Productivity
If the Ce substitution amount is increased to enhance fluorescence, then the light conversion efficiency is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent applies parameter changes by defining a specific range for Ce substitution amount (0.5 to 10 mol % of M). This quantitative specification resolves the contradiction by establishing an optimal Ce content range that achieves high blue light conversion efficiency while providing clear manufacturing guidelines, thereby reducing the complexity of production control.
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 powder achieves high fluorescence peak intensity, internal quantum efficiency, and improved blue light conversion efficiency when irradiated with blue light, suitable for light-emitting devices and image display applications.
Implementation Method 1
a phosphor is used as a wavelength conversion material for obtaining white light from blue light emitted from a blue LED
Implementation Method 2
a phosphor powder which includes phosphor particles which are a phosphor represented by a general formula Mx(Si, Al)2(N, O)3±y... having a high fluorescence peak intensity when the phosphor is irradiated with blue light
Data Source
AI summary
A phosphor powder including phosphor particles which are a phosphor represented by a general formula Mx(Si, Al)2(N, O)3±y (where M is Li and one or more alkaline earth metal elements and 0.52≤x≤0.9 and 0.06≤y≤0.36 are satisfied) and in which a part of M is substituted with a Ce element, wherein a Si/Al atomic ratio is equal to or more than 1.5 and equal to or less than 6, an O/N atomic ratio is equal to or more than 0 and equal to or less than 0.1, 5 to 50 mol % of M is Li, and 0.5 to 10 mol % of M is Ce, and a total content of a Cr element, a Fe element, and a Ni element in the phosphor powder is equal to or less than 20.0 ppm.