Atmospheric Sintering of Red Phosphor for LED Luminance
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Solution Overview
Problem
Conventional red phosphors used in light-emitting diodes (LEDs) suffer from low luminance, color rendering property, and color saturation due to their short lifespan and high manufacturing costs, with existing methods requiring high pressure and equipment costs, and resulting in narrow wavelength ranges.
Innovation Solution
A method involving a sintering holder with an adhesion agent to produce a phosphor with a precisely controlled element composition, specifically CaaSrbAlcSidOeNf:Eug, under a non-oxidizing gas atmosphere, which enhances luminance and color properties by minimizing chemical composition differences and preventing contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high pressure sintering is used to produce red phosphor, then the phosphor can be manufactured, but the manufacturing cost increases and equipment complexity increases
Solution Approach 1:
The patent changes the sintering parameters from high pressure (>10 atm) to atmospheric pressure conditions, combined with specific temperature ranges and atmosphere control, to achieve the same phosphor production without requiring expensive high-pressure equipment
Solution Approach 2:
The invention replaces expensive, complex high-pressure sintering equipment with simple, inexpensive atmospheric pressure sintering apparatus, significantly reducing manufacturing costs while maintaining phosphor quality
2Reliability
If high pressure sintering is used to produce red phosphor, then the phosphor can be manufactured, but the equipment complexity and manufacturing cost increase
Solution Approach 1:
The patent simplifies the sintering process by changing from high-pressure conditions to atmospheric pressure, eliminating the need for complex pressure control systems while maintaining effective phosphor synthesis through optimized temperature and atmosphere parameters
3Ease of manufacture
If conventional sintering method is used, then the manufacturing process is simple, but the color rendering property and color saturation cannot be greatly increased
Solution Approach 1:
The patent optimizes sintering parameters including temperature ranges, holding times, and atmosphere composition to control phosphor crystal growth and composition, achieving superior color rendering properties while maintaining atmospheric pressure processing simplicity
Solution Approach 2:
The invention applies specific local conditions during sintering, such as controlled oxygen partial pressure and temperature gradients, to enhance the optical properties of the phosphor in specific regions of the sintered product
4Ease of manufacture
If conventional sintering method is used, then the manufacturing process is simple, but the luminance requirement cannot be satisfied
Solution Approach 1:
The patent adjusts sintering parameters including extended holding times at optimized temperatures and controlled atmosphere composition to enhance the luminescent efficiency of the phosphor, achieving high luminance output through atmospheric pressure processing
5Ease of manufacture
If the wavelength range of red phosphor is narrow, then the manufacturing is simpler, but the color rendering property and color saturation cannot be greatly increased
Solution Approach 1:
The patent controls sintering parameters to broaden the emission wavelength range of the red phosphor, achieving improved color saturation and rendering properties while maintaining the simplicity of atmospheric pressure manufacturing processes
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 method achieves higher luminance and color rendering properties, reducing manufacturing costs and preventing contamination, resulting in a phosphor with improved chromaticity and luminance for use in LEDs.
Implementation Method 1
coating an adhesion agent on at least one of the main body and the closure member
Implementation Method 2
heating the sintering holder containing the raw material under a non-oxidizing gas atmosphere to obtain a phosphor
Data Source
AI summary
A method of providing a phosphor with a precisely controlled element composition, a phosphor provided by the same, and a red phosphor represented by the [formula 1] are disclosed, in whichCaaSrbAlcSidOeNf: Eug [formula 1]wherein 0≦a<1, 0<b<1, c=1, 0.8≦d≦1.2, 0≦e≦0.5, 2.5≦f≦3.1, 0.002≦g≦0.020, a and b are not both 0 at the same time; anda CIE1931 chromaticity coordinates (x, y) of a light emitted from the phosphor, which is excited by a wavelength of 455 nm, satisfies the formulae:x=[(−0.1059b3+0.068b2−0.06b)+(2152.8g3−309.2g2+8.2943g)+0.6324]±0.01;y=[(−0.1295b3−0.0968b2+0.0702b)+(−3299.2g3+311.08g2−7.9266g)+0.3621]±0.01.The present invention also provides a light emitting device comprising the said red phosphor.