Long Wavelength LYSN Phosphor Temperature Quenching
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Solution Overview
Problem
Conventional LYSN phosphors exhibit decreased emission luminance and temperature maintenance under high power conditions, particularly in longer wavelength ranges, and require additional red phosphors for color compensation, while existing ceramic phosphor composites suffer from low internal quantum efficiency and poor heat dissipation.
Innovation Solution
A long wavelength LYSN phosphor with a specific crystal lattice size and constitutional element ratio is developed, eliminating the need for red phosphors and enhancing emission luminance and temperature stability through a tetragonal crystal phase composition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If YAG phosphor is used under high power, then the light emitting device can operate at high power, but the luminance decreases due to temperature quenching
Solution Approach 1:
The patent changes the chemical composition parameters of the phosphor by incorporating multiple rare earth elements (Y, Gd, Tb, Lu) in specific ratios to modify the crystal structure and reduce temperature quenching effects, thereby maintaining luminance at high power operation
Solution Approach 2:
The patent creates a composite phosphor material combining multiple rare earth elements with silicon nitride base, forming a new composite material that exhibits both high power capability and maintained luminance through synergistic effects of the constituent elements
2Illumination intensity
If the emission color wavelength is increased to 550 nm or more, then the color rendering is improved, but the temperature properties are significantly deteriorated
Solution Approach 1:
The patent adjusts the compositional parameters by controlling the ratios of rare earth elements (particularly Gd and Tb content) to shift the emission wavelength to 550 nm or more while simultaneously optimizing the crystal structure to maintain stable temperature properties
3Illumination intensity
If conventional LYSN phosphors are used, then the phosphor can emit yellow light, but the emission luminance decreases and temperature maintenance is poor under high power conditions
Solution Approach 1:
The patent develops a composite phosphor material combining LYSN base with multiple rare earth elements (Y, Gd, Tb, Lu) to create a new composite that maintains yellow light emission while significantly improving emission luminance and temperature maintenance through the synergistic effects of the rare earth elements
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 high emission luminance and temperature maintenance in the 546 to 570 nm range, achieving high color rendering properties without red phosphors, and improves the durability and heat resistance of light emitting devices.
Implementation Method 1
a phosphor is disposed on an LED chip which emits blue light or light having a near-ultraviolet wavelength... excitation light using blue light from the blue light LED chip
Implementation Method 2
as the temperature of the phosphors increases, the luminance decreases, so-called temperature quenching is large
Data Source
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AI summary
The present invention provides an LYSN phosphor having an emission peak in a long wavelength range, and having high emission luminance and a high temperature maintenance rate. The present invention is a phosphor including a tetragonal crystal phase, in which the crystal phase includes M element, La, A element, Si, and N, and satisfies a specific expression, and a lattice constant a is 10.104 Å or more and 10.154 Å or less.