LED Wavelength Conversion via Group III Nitride Doping
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Solution Overview
Problem
Conventional light emitting diodes face challenges in achieving uniform color reproduction due to phosphor particle settlement and additional manufacturing processes required for wavelength conversion, leading to unstable colors and increased costs, especially in miniaturized devices.
Innovation Solution
A light emitting diode with a wavelength conversion layer formed using Group III nitride semiconductors doped with rare earth elements, which can be integrated into the existing semiconductor process, allowing for uniform wavelength conversion and simplifying manufacturing without additional steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If phosphor powder is mixed with epoxy for wavelength conversion, then wavelength conversion can be achieved, but phosphor particles settle during curing causing non-uniform light emission and poor color reproducibility
Solution Approach 1:
The patent extracts the phosphor material from the epoxy resin matrix and applies it directly to the light emitting chip surface. This separation eliminates the settlement problem that occurs when phosphor particles are suspended in liquid epoxy during curing, while still achieving effective wavelength conversion for producing uniform colored light.
2Ease of manufacture
If additional receptors, reflectors or protrusions are formed to prevent epoxy flow, then liquid epoxy can be contained, but manufacturing process time and cost increase
Solution Approach 1:
The patent removes the epoxy resin component entirely from the wavelength conversion structure, applying phosphor material directly to the chip. This eliminates the need for additional containment structures like receptors, reflectors, or protrusions, thereby simplifying the manufacturing process and reducing production time and costs.
3Productivity
If phosphor amount is not uniform during manufacturing, then production is faster, but unstable colors are produced due to yield problems
Solution Approach 1:
The patent applies phosphor material directly to the light emitting chip surface in a localized manner, allowing precise control of phosphor distribution. This direct application method ensures uniform phosphor coverage and consistent color output while maintaining efficient production, resolving the trade-off between manufacturing speed and color stability.
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
This approach enables stable and uniform color emission, reduces manufacturing costs and time, and facilitates the production of compact, high-quality light emitting diodes suitable for display and backlight applications in portable electronic devices.
Implementation Method 1
a wavelength conversion layer formed on the light emitting layer... capable of uniformly emitting light of a desired color by converting wavelength of an intrinsic emission color of a light emitting diode chip
Data Source
AI summary
The present invention provides a light emitting diode which comprises a substrate, a light emitting layer including an N-type semiconductor layer and a P-type semiconductor layer formed on the substrate, and a wavelength conversion layer formed on the light emitting layer or on the back of the substrate. The wavelength conversion layer is formed of a Group III nitride semiconductor doped with rare earth elements. The rare earth elements include at least one of Tm, Er and Eu. According to a light emitting diode of the present invention, a desired color can be implemented in various ways by converting the wavelength of primary light emitted from a light emitting chip. Thus, the reliability and quality of products can be improved due to the uniform emission of light with a desired color. Further, since the existing semiconductor process can be utilized in the present invention, its fabrication process can be simplified, process cost and time can be reduced, and the compact products can be obtained.