LED Stability Layer for Nanocrystal Heat Dissipation

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Solution Overview

Problem

Semiconductor nanocrystals in LED devices degrade over time, leading to reduced quantum yield and red shift in light emission, which affects the efficiency and longevity of the devices, especially in applications requiring high-quality white light emission.

Innovation Solution

Incorporating a stability layer made of matrix materials like urethane/acrylate between the LED chip and the semiconductor nanocrystal complex, which dissipates heat and optimizes the distance for maximum light output, while using semiconductor nanocrystal complexes that absorb light from the diode chip and emit at a different wavelength, enhancing the efficiency and longevity of the LED device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If semiconductor nanocrystals are placed directly on the LED chip, then light absorption and emission efficiency is maximized, but the nanocrystals degrade over time due to heat and reduced quantum yield

Engineering Contradiction:

Improvelight emission efficiencyVSAvoiddevice lifespan

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

A stability layer made of matrix material (such as urethane/acrylate) is introduced as an intermediary between the LED chip and semiconductor nanocrystals. This stability layer dissipates heat away from the nanocrystals, preventing degradation while maintaining optimal light absorption and emission efficiency. The layer optimizes the distance for maximum light output without direct contact between the chip and nanocrystals.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If semiconductor nanocrystals are used to convert light wavelength, then color tuning capability is improved, but quantum yield decreases over time due to degradation

Engineering Contradiction:

Improvewavelength conversion capabilityVSAvoidquantum yield stability

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The stability layer acts as a protective cushion placed beforehand between the heat-generating LED chip and the semiconductor nanocrystals. This preemptive measure dissipates heat before it can reach the nanocrystals, preventing degradation and maintaining stable quantum yield and color properties over the device lifetime.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Use of energy by moving object

If the distance between LED chip and nanocrystals is minimized, then light absorption is maximized, but heat transfer to nanocrystals increases causing degradation

Engineering Contradiction:

Improvelight absorption efficiencyVSAvoidheat exposure to nanocrystals

Core Design Contradiction:

Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The stability layer serves as a thermal mediator that allows optical energy transfer while blocking harmful thermal energy. The matrix material in this layer absorbs and dissipates heat away from the nanocrystals while maintaining transparency to light, thus preserving both absorption efficiency and thermal stability.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 stability layer increases the quantum yield and extends the lifespan of the LED device by maintaining light output and emission efficiency, with the semiconductor nanocrystal complexes contributing to improved brightness and color consistency over time.

Implementation Method 1

semiconductor nanocrystal complexes that absorb light from the diode chip and emit at a different wavelength

Methodology Applied

Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

stability layer made of matrix materials like urethane/acrylate between the LED chip and the semiconductor nanocrystal complex, which dissipates heat

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS8643052B2Light emitting diode comprising semiconductor nanocrystal complexes

Publication Date: 2014.02.04 SAMSUNG ELECTRONICS CO LTD

AI summary

A light emitting diode (LED) formed by depositing an LED chip and coupling a stability layer to the LED chip. Semiconductor nanocrystals are placed in a first matrix material to form a nanocrystal complex layer. The nanocrystal complex layer is deposited on top of the stability layer. A thickness of the stability layer is chosen to maximizes a power of a light output by the nanocrystal complex layer. The matrix material and the stability layer can be of the same type of material. Additional layers of matrix material can be deposited on top of the nanocrystal complex layer. These additional layers can comprise matrix material only or can comprise matrix material and semiconductor nanocrystals to form another nanocrystal complex layer.