Semiconductor LED Wavelength Conversion Void Lattice
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Solution Overview
Problem
Conventional white LEDs face issues with non-uniform light emission and color gamut degradation due to path differences and non-uniform phosphor distribution in the filler material, leading to inefficient light extraction and color accuracy.
Innovation Solution
A semiconductor light emitting device with a wavelength conversion layer made of light-transmissive material containing phosphor particles or quantum dots, featuring a lattice pattern of voids that increase the effective area and refract light for improved external light extraction efficiency, while being exposed or filled with materials like SiO2, TiO2, and Al2O3 to enhance light diffusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If phosphor powder is mixed with molding filler in a package structure, then white light can be produced through wavelength conversion, but light path differences cause non-uniform light emission and color gamut degradation
Solution Approach 1:
The invention extracts the phosphor wavelength conversion function from the package filler material and integrates it directly into the semiconductor light emitting device structure. The phosphor layer is formed as a distinct functional layer on the semiconductor chip, separating the wavelength conversion function from the package structure, thereby eliminating light path differences caused by package geometry and achieving uniform light emission.
Solution Approach 2:
The invention merges the phosphor wavelength conversion layer with the semiconductor light emitting device structure itself, rather than keeping it separate in the package filler. The phosphor layer is integrated onto the semiconductor chip surface, combining the light generation and wavelength conversion functions in a single unified structure, which eliminates the need for complex package arrangements and achieves uniform light output.
2Ease of manufacture
If a simple filler structure is used, then manufacturing is easier, but light extraction efficiency is reduced due to total internal reflection
Solution Approach 1:
The invention introduces a porous or lattice-like microstructure within the phosphor layer or adjacent structures. This porous structure creates multiple light scattering interfaces that reduce total internal reflection and improve light extraction efficiency. The porous structure can be formed through simple fabrication processes such as etching or deposition, maintaining manufacturing ease while significantly enhancing light extraction.
Solution Approach 2:
The invention introduces micro-scale three-dimensional structures (such as protrusions, recesses, or lattice patterns) into the phosphor layer or semiconductor chip surface. These dimensional features create additional light extraction pathways by disrupting total internal reflection, improving light extraction efficiency without adding complex manufacturing steps, as the structures can be formed through standard semiconductor fabrication techniques.
3Measurement precision
If phosphor is distributed in filler material, then wavelength conversion occurs, but non-uniform phosphor distribution degrades color gamut
Solution Approach 1:
The invention segments the phosphor distribution into a controlled layered structure with specific spatial arrangement. Instead of random distribution in filler material, the phosphor is organized in distinct layers or regions with defined thickness and composition gradients. This segmentation enables precise control over phosphor concentration and distribution, ensuring uniform color output and accurate color gamut while maintaining effective wavelength conversion.
4Volume of moving object
If a compact package design is pursued, then device size is reduced, but light extraction efficiency decreases due to increased path differences
Solution Approach 1:
The invention changes the optical parameters of the phosphor layer and surrounding structures to optimize light extraction in compact geometries. By adjusting phosphor concentration, layer thickness, refractive index matching, and introducing micro-scale optical features, the device achieves high light extraction efficiency within a reduced volume. These parameter optimizations allow compact packaging without sacrificing light extraction performance.
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 achieves uniform light emission, reduces light absorption, and enhances external light extraction efficiency, allowing for a more compact package design with reduced color blurs and improved color gamut.
Implementation Method 1
a wavelength conversion layer formed on an upper light emission surface of the light emission structure, made of a light-transmissive material including phosphor particles or quantum dots
Implementation Method 2
performing wavelength conversion by using a yellow phosphor in a blue LED to combine blue light and yellow light to thus implement a white light source
Implementation Method 3
having a plurality of voids formed therein... the plurality of voids forming lattice patterns... to enhance light diffusion
Implementation Method 4
At least some of the voids may be filled with a material having a refractive index different from that of the wavelength conversion layer... to enhance light diffusion
Data Source
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AI summary
A semiconductor light emitting device includes: a light emission structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; and a wavelength conversion layer formed on at least a portion of a light emission surface of the light emission structure, made of a light-transmissive material including phosphor particles, and having a void therein. A semiconductor light emitting device includes: a light emission structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; and a wavelength conversion layer formed on at least a portion of a light emission surface of the light emission structure, made of a light-transmissive material including phosphor particles or quantum dots, and having a void therein.