Wavelength Conversion Element With Zinc Oxide C-Axis Orientation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional wavelength conversion elements in LED systems face challenges in adjusting chromaticity due to light emission nonuniformity from LED chips and suffer from light scattering and void formation, which reduces optical output and shifts chromaticity, especially when using zinc oxide as a matrix.
Innovation Solution
A wavelength conversion element comprising a first phosphor layer of crystalline zinc oxide in c-axis orientation and a second phosphor layer with a material having a lower refractive index, allowing for adjustable chromaticity by controlling the thickness ratio between the layers, thereby minimizing light scattering and void formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If zinc oxide is used as a matrix material in the wavelength conversion element, then the refractive index is improved (higher refractive index), but light scattering increases and optical output decreases
Solution Approach 1:
The patent applies local quality by creating distinct regions with different refractive indices within the wavelength conversion element. Specifically, it forms a first wavelength conversion layer with zinc oxide matrix (higher refractive index) and a second wavelength conversion layer with different matrix material (lower refractive index), allowing each region to serve its specific optical function while minimizing overall light scattering
Solution Approach 2:
The patent uses composite materials by combining zinc oxide particles with different matrix materials (resin or glass) to create wavelength conversion layers with optimized optical properties. The composite structure allows the high refractive index zinc oxide to enhance light extraction while the matrix material controls light scattering, achieving a balance between the two opposing requirements
2Manufacturing precision
If the chromaticity is adjusted by changing phosphor amount or type, then the chromaticity uniformity is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent segments the wavelength conversion element into multiple layers, each with specific phosphor compositions and ratios. This segmentation allows independent optimization of each layer's chromaticity characteristics, enabling precise control of overall chromaticity uniformity while simplifying the manufacturing process through modular assembly
Solution Approach 2:
The patent transitions from adjusting chromaticity through a single parameter (phosphor amount in one layer) to a multi-dimensional approach by controlling phosphor composition, layer thickness, and spatial distribution across multiple layers. This dimensional expansion provides more degrees of freedom for achieving uniform chromaticity
3Adaptability or versatility
If a single wavelength conversion layer is used, then the device complexity is reduced, but the chromaticity adjustment range is limited
Solution Approach 1:
The patent implements multi-functionality by designing a layered structure where each layer serves multiple purposes: the first layer with zinc oxide matrix provides both wavelength conversion and high refractive index for light extraction, while the second layer provides chromaticity adjustment and light diffusion. This multi-functional design expands chromaticity adjustment range without proportionally increasing device complexity
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 configuration enables precise adjustment of chromaticity and enhances optical output by reducing light scattering and voids, ensuring consistent light emission with high efficiency.
Implementation Method 1
a first phosphor layer which includes a part of the plurality of phosphor particles and a first matrix that is located among the part of the plurality of phosphor particles and is formed of zinc oxide in a c-axis orientation
Implementation Method 2
a second phosphor layer which includes a remaining part of the plurality of phosphor particles and a second matrix that is located among the remaining part of the plurality of phosphor particles and is formed of a material having a refractive index that is lower than a refractive index of the zinc oxide
Implementation Method 3
zinc oxide in a c-axis orientation
Data Source
AI summary
A wavelength conversion element includes: a plurality of phosphor particles; a first matrix located among a part of the plurality of phosphor particles and formed of zinc oxide in a c-axis orientation; and a second matrix located among a remaining part of the plurality of phosphor particles and formed of a material having a refractive index that is lower than a refractive index of the zinc oxide.