Wavelength Conversion Device Reflective Layer Thermal Management

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Solution Overview

Problem

Conventional wavelength conversion devices using metal reflective layers suffer from reduced reflectivity and thermal stability due to air penetration and chemical reactions, leading to inefficiencies in light utilization and heat dissipation, particularly under high power and high brightness conditions.

Innovation Solution

A wavelength conversion device with a thin reflective layer composed of aluminum oxide and titanium oxide particles, along with a binder, which achieves high reflectivity (>95%) and improved thermal conductivity by filling voids between reflective particles, thereby enhancing light utilization efficiency and heat dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a micro LED array is used to achieve high resolution and low power consumption, then display quality and energy efficiency are improved, but the requirement for precise wavelength conversion increases device complexity

Engineering Contradiction:
Improvedisplay qualityVSAvoidwavelength conversion structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The wavelength conversion layer is segmented into multiple distinct layers, each containing quantum dots with specific bandgap energies tailored to convert specific blue LED wavelengths to desired colors. This segmentation enables precise wavelength control while maintaining the simplicity of a single blue LED source, resolving the contradiction between display quality and device complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the parameter of quantum dot bandgap energy across different layers to achieve wavelength conversion. By adjusting the composition and structure of quantum dots in each layer, the system converts a single blue wavelength into multiple precise color wavelengths, improving display quality without adding complex multi-LED structures.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If multiple quantum dot layers are stacked to achieve precise wavelength conversion, then color accuracy is improved, but light absorption by upper layers reduces overall efficiency

Engineering Contradiction:
Improvecolor accuracyVSAvoidlight absorption loss
Core Design Contradiction:
Manufacturing precisionVSLoss of energy

Solution Approach 1:

Each quantum dot layer is designed with local quality optimized for its specific wavelength conversion function. The quantum dots in each layer have precisely controlled bandgap energies that match the conversion needs of that specific layer, ensuring efficient conversion while minimizing unnecessary absorption. This local optimization reduces energy loss while maintaining color accuracy.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If quantum dots with different bandgap energies are used in different layers, then wavelength precision is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvewavelength precisionVSAvoidlayer fabrication
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent systematically changes the bandgap energy parameter of quantum dots across layers by adjusting their composition and structure. This parameter change approach enables precise wavelength control while using a consistent manufacturing methodology for each layer, making the complex multi-layer structure more manufacturable through standardized processes.

Inventive Principle:
Principle #35Parameter changes

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 results in a high reflectivity and thin reflective layer that maintains thermal stability, improving light emission efficiency and reducing material costs while preventing heat accumulation, thus addressing the limitations of conventional technologies.

Implementation Method 1

a first quantum dot layer including first quantum dots having a first bandgap energy to convert a first wavelength of the micro LED to a first wavelength in a green portion of the visible spectrum; a second quantum dot layer including second quantum dots having a second bandgap energy to convert the first wavelength of the micro LED to a second wavelength in a red portion of the visible spectrum

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

Each of the plurality of quantum dot layers includes quantum dots having different bandgap energies, such that each of the quantum dot layers converts the blue LED's wavelength to a different wavelength

Methodology Applied
Scientific EffectPhotonic bandgap conversion: Absorption (EM radiation)

Data Source

PatentEP3150909B1Wavelength conversion device and related light-emitting device thereof
Publication Date: 2020.11.04 APPOTRONICS CORP LTD
  • EP3150909B1 patent drawingFigure 1~2
  • EP3150909B1 patent drawingFigure 3

AI summary

Provided is a wavelength conversion device (100), comprising a substrate (130), a reflecting layer (120), and a light-emitting layer (110) superimposed successively. The light-emitting layer (110) contains a wavelength conversion material and a second binder, and the reflecting layer (120) contains reflecting particles, auxiliary particles, and a first binder. The reflecting particles are used for reflecting light, and the auxiliary particles are used for filling voids between the reflecting particles. The first binder is used for binding the reflecting particles and auxiliary particles into a layer. The reflecting layer (120) not only ensures a higher reflectivity, but also achieves a lower thickness, such that the heat produced by the light-emitting layer (110) can be better transmitted to the substrate through the reflecting layer (120), which avoids a decrease in the light conversion efficiency caused by an excessively high temperature of the light-emitting layer (110). Also disclosed is a light-emitting device comprising such a wavelength conversion device (100).