Quantum Dot Inorganic Encapsulation for Optoelectronic Thermal Management

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Solution Overview

Problem

Existing optoelectronic components, such as light-emitting diodes, require thick converter elements for full conversion, which limits heat transfer and application temperature due to the use of polymer matrices like silicone, leading to pixel-to-pixel crosstalk and reduced contrast in pixel applications.

Innovation Solution

The use of quantum dots with an inorganic encapsulation that surrounds the wavelength-converting core in a cohesive and form-fitting manner, allowing for a high-density packing without additional matrix material, preventing energy transfer and quenching, and enhancing heat transfer by reducing the layer thickness of the conversion element.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a thick converter element is used for full conversion, then conversion efficiency is improved, but heat transfer capability deteriorates and application temperature is limited

Engineering Contradiction:

Improveconversion efficiencyVSAvoidapplication temperature

Core Design Contradiction:

Use of energy by moving objectVSTemperature

Solution Approach 1:

The patent changes the material parameter from organic polymer matrix to inorganic encapsulation material, which fundamentally alters the thermal conductivity properties while maintaining the wavelength conversion function. This allows the converter element to operate at higher temperatures with improved heat transfer capability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite structure where inorganic encapsulation materials surround the quantum dots or phosphors. This composite approach combines the optical conversion properties of the active material with the superior thermal management properties of the inorganic encapsulation, resolving the contradiction between conversion efficiency and heat transfer.

Inventive Principle:

Principle #40Composite materials

2Use of energy by moving object

If a thick converter element is used for full conversion, then conversion efficiency is improved, but pixel-to-pixel crosstalk increases and contrast deteriorates

Engineering Contradiction:

Improveconversion efficiencyVSAvoidcontrast

Core Design Contradiction:

Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

By changing the material composition to inorganic encapsulation with high thermal conductivity, the patent enables thinner converter elements to achieve full conversion without the need for thick layers. This reduction in thickness directly reduces pixel-to-pixel crosstalk and improves contrast while maintaining conversion efficiency.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If polymer matrix material is used in converter element, then ease of manufacture is improved, but heat transfer capability deteriorates

Engineering Contradiction:

Improveease of manufactureVSAvoidheat transfer capability

Core Design Contradiction:

Ease of manufactureVSTemperature

Solution Approach 1:

The patent creates a composite structure where inorganic encapsulation materials are integrated with the quantum dots or phosphors. This composite approach maintains manufacturability through established deposition techniques while dramatically improving heat transfer capability compared to pure polymer matrices.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent substitutes the organic polymer matrix with inorganic encapsulation materials, replacing a material with poor thermal conductivity with one that has superior thermal management properties. This substitution maintains the structural and functional integrity of the converter element while resolving the heat transfer limitation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 full conversion of radiation with improved thermal management, reduced self-absorption losses, and increased durability against environmental influences, resulting in enhanced efficiency and contrast for optoelectronic components with a thinner conversion layer.

Implementation Method 1

The quantum dots are configured for the wavelength conversion of radiation, in particular the radiation emitted by the semiconductor chip

Methodology Applied

Scientific EffectWavelength conversion: Photoluminescence

Implementation Method 2

The distance is greater than 10 nm to avoid FRET energy transfer and quenching of quantum dot conversion efficiency

Methodology Applied

Scientific EffectFRET energy transfer prevention:

Implementation Method 3

little heat flows from the converter element (stokes energy) through the matrix material, in particular polymers such as silicone, to the semiconductor chip heat sink

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentUS11563154B2Optoelectronic component and method of producing an optoelectronic component

Publication Date: 2023.01.24 OSRAM OLED

AI summary

An optoelectronic component is disclosed. In an embodiment an optoelectronic component includes a semiconductor chip configured to emit radiation and a conversion element including quantum dots, the conversion element configured to convert a wavelength of the radiation, wherein each quantum dot includes a wavelength-converting core and an inorganic encapsulation, wherein inorganic encapsulations form a matrix material of at least adjacent quantum dots, and wherein the adjacent quantum dots have a distance of at least 10 nm.