Nitride Phosphor Particle Morphology for Higher Luminous Flux
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Solution Overview
Problem
Existing nitride phosphors used in light emitting devices do not provide sufficient luminous flux, limiting the efficiency of these devices.
Innovation Solution
A nitride phosphor with a specific composition and particle characteristics, including a range of molar content ratios and shape parameters, is developed to enhance luminous flux by reducing light emission loss through uniform dispersion in a resin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional nitride phosphors are used in light emitting devices, then the device structure is simple, but the luminous flux is insufficient
Solution Approach 1:
The patent applies parameter changes by precisely controlling the molar ratios of elements in the phosphor composition (Eu:Al = 0.002-0.08, Si:Al = 0.8-1.2, (Group 2 element + Eu):Al = 0.8-1.1) and particle morphology parameters (circularity 0.82-0.92, aspect ratio 0.72-0.77) to optimize luminous flux output while managing composition complexity
Solution Approach 2:
The patent uses composite materials by combining multiple elements (Group 2 element, Eu, Si, Al, N) in specific proportions to create a novel nitride phosphor compound that achieves high luminous flux. The composite structure allows synergistic effects among elements to enhance light emission performance
2Loss of energy
If nitride phosphor particles are dispersed in resin, then light emission loss is reduced, but particle aggregation occurs leading to non-uniform dispersion
Solution Approach 1:
The patent applies spheroidality by controlling particle circularity to be 0.82-0.92, making particles nearly spherical. This shape reduces particle aggregation and improves dispersion uniformity in the resin matrix, thereby reducing light emission loss while maintaining stable composition distribution
Solution Approach 2:
The patent uses parameter changes by optimizing the aspect ratio (0.72-0.77) and circularity (0.82-0.92) parameters of phosphor particles to achieve a balance between reducing light emission loss and maintaining uniform dispersion stability in the resin
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 nitride phosphor achieves higher luminous flux by minimizing light reabsorption and emission loss, resulting in improved light emitting device performance.
Implementation Method 1
a nitride phosphor having a composition that includes Eu, Si, Al, N, and a Group 2 element... a ratio of a total molar content of the Group 2 element and Eu is in a range of 0.8 to 1.1... the nitride phosphor has an average value of an aspect ratio, which is a minor-axis-to-major-axis ratio, in a range of 0.72 to 0.77, and an average circularity in a range of 0.82 to 0.92
Data Source
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AI summary
A nitride phosphor, having a composition that contains Eu, Si, Al, N, and a Group 2 element containing at least one selected from the group consisting of Mg, Ca, Sr, and Ba. With respect to a molar content of Al in the composition, a ratio of a total molar content of the Group 2 element and Eu is in a range of 0.8 to 1.1, a ratio of a molar content of Eu is in a range of 0.002 to 0.08, a ratio of a molar content of Si is in a range of 0.8 to 1.2, and a ratio of a total molar content of Si and Al is in a range of 1.8 to 2.2. The nitride phosphor has an average value of an aspect ratio, which is a minor-axis-to-major-axis ratio, in a range of 0.72 to 0.77, and an average circularity in a range of 0.82 to 0.92.