Nitride Phosphor Composition for Warm Color LED Emission
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Solution Overview
Problem
Conventional nitride phosphors for white LEDs are limited in producing warm colors, particularly red light, and face challenges in high-purity material production, leading to increased costs and limited options for phosphor ingredients, which restricts the development of cost-effective, high-emission intensity light-emitting devices with a large special color rendering index.
Innovation Solution
A novel phosphor composition represented by the formula aM3N2.bAlN.cSi3N4, where M is Mg, Ca, Sr, Ba, or Zn, is developed, allowing for the production of a phosphor host that emits warm colors, particularly red light, through a method involving the reaction of alkaline-earth metal oxides, silicon, aluminum, and carbon in a nitriding gas atmosphere, enabling mass production and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional nitride phosphors are used, then light-emitting devices can be produced, but the emission intensity in warm colors particularly red light is insufficient
Solution Approach 1:
The patent changes the chemical composition parameters of the phosphor by introducing a new formula aM3N2.bAlN.cSi3N4 with specific ratio constraints (0.1≤a/(a+b)≤0.5, 0.3≤b/(b+c)≤0.7, 0.2≤c/(c+a)≤0.6), which optimizes the emission characteristics in warm colors while maintaining structural stability
Solution Approach 2:
The patent creates a composite phosphor material combining multiple nitride compounds (M3N2, AlN, Si3N4) in specific proportions, where M represents alkaline earth metals. This composite structure enables enhanced emission intensity in warm colors while providing flexibility in material selection
2Manufacturing precision
If high-purity phosphor materials are produced using conventional methods, then emission quality improves, but production costs increase
Solution Approach 1:
The patent modifies the production parameters by controlling the molar ratios of starting materials within specific ranges (a/(a+b), b/(b+c), c/(c+a)) during the nitriding process, which enables achieving high purity phosphor products with optimized emission characteristics while maintaining cost-effectiveness through controlled synthesis conditions
3Adaptability or versatility
If conventional phosphor compositions are used, then production processes are simple, but the special color rendering index is limited
Solution Approach 1:
The patent optimizes the compositional parameters of the phosphor material by establishing specific ratio relationships between different nitride components (aM3N2, bAlN, cSi3N4), which enhances the color rendering properties particularly for warm colors while keeping the synthesis process manageable through defined compositional constraints
Solution Approach 2:
The patent develops a composite phosphor system combining multiple nitride phases with complementary emission characteristics. The composite structure aM3N2.bAlN.cSi3N4 provides synergistic effects that improve color rendering index, particularly R9 for red light, while the defined compositional ranges maintain manufacturing feasibility
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 solution provides a phosphor composition with high internal quantum efficiency, enabling the production of low-cost, high-emission intensity light-emitting devices with enhanced color rendering capabilities, specifically in warm colors like red, and expands the range of phosphor ingredients available for white LEDs.
Implementation Method 1
a phosphor composition which contains a phosphor host having as a main component a composition represented by a composition formula: aM3N2.bAlN.cSi3N4... This phosphor composition is excited with near-ultraviolet light, violet light, or blue light to emit light in a warm color such as orange or red
Implementation Method 2
a method for producing the phosphor composition including allowing a material, which contains a compound capable of generating an oxide of at least one element selected from the group consisting of Mg, Ca, Sr, Ba, and Zn by heating, a silicon compound, an aluminum compound, a compound containing an element forming a luminescent center ion, and carbon, to react in a nitriding gas atmosphere
Data Source
AI summary
A light-emitting device is produced using a phosphor composition containing a phosphor host having as a main component a composition represented by a composition formula: aM3N2.bAlN.cSi3N4, where “M” is at least one element selected from the group consisting of Mg, Ca, Sr, Ba, and Zn, and “a”, “b”, and “c” are numerical values satisfying 0.2≦a/(a+b)≦0.95, 0.05≦b/(b+c)≦0.8, and 0.4≦c/(c+a)≦0.95. This enables a light-emitting device emitting white light and satisfying both a high color rendering property and a high luminous flux to be provided.