Quantum Dot Double-Shell Structure for Oxidation Resistance

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Solution Overview

Problem

Quantum dots are susceptible to oxidation in the presence of water and oxygen, leading to shifts in luminous wavelengths, widening of the full width at half maximum of the luminous spectrum, and decay in quantum efficiency, necessitating improved moisture and oxygen resistance.

Innovation Solution

A quantum dot structure comprising a core, a first shell discontinuously distributed around the core surface, and a second shell with an irregularly shaped outer surface, along with a gap between the shells, enhances resistance to environmental damage factors. The method involves forming quantum dots by injecting shell precursor solutions at specific rates to achieve the desired shell structure, followed by purification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If quantum dots are used for wavelength conversion, then color saturation and quantum efficiency are improved, but susceptibility to oxidation by water and oxygen worsens

Engineering Contradiction:

Improvecolor saturationVSAvoidresistance to oxidation

Core Design Contradiction:

Illumination intensityVSReliability

Solution Approach 1:

The patent applies nested shell structures (first shell and second shell) around the quantum dot core, creating multiple protective layers. The first shell is discontinuously distributed around the core surface, while the second shell encapsulates the core and has an irregularly shaped outer surface, forming a nested configuration that progressively shields the core from environmental damage factors like water and oxygen.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent uses composite material structures combining different shell materials with specific properties. The first shell and second shell are made of materials that provide complementary protection mechanisms, creating a composite protective system that enhances overall resistance to oxidation while maintaining the quantum dot's optical performance.

Inventive Principle:

Principle #40Composite materials

2Stability of the object's composition

If quantum dots are exposed to water and oxygen, then oxidation occurs causing wavelength shifting and spectrum widening, but protection structures increase device complexity

Engineering Contradiction:

Improveluminous wavelength stabilityVSAvoidshell structure complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The protective structure is segmented into distinct functional components: a first shell with discontinuous distribution around the core surface and a second shell with irregular outer surface that encapsulates the core. This segmentation allows each shell to perform specific protective functions while maintaining overall structural efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements local quality variations in the shell structures, where the first shell is discontinuously distributed in specific regions around the core surface, and the second shell has an irregularly shaped outer surface with varying thickness. This local differentiation optimizes protection in areas most susceptible to oxidation while minimizing unnecessary material usage.

Inventive Principle:

Principle #3Local quality

3Reliability

If shell structures are added to protect quantum dots, then resistance to moisture and oxygen is improved, but manufacturing precision requirements increase

Engineering Contradiction:

Improvemoisture and oxygen resistanceVSAvoidshell formation control

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent utilizes parameter changes during the shell formation process, specifically controlling the injection rate of shell precursor solution (0.016-1.6 eq/min) and heating temperature to achieve the desired discontinuous first shell and irregular second shell structures. These parameter optimizations enable reproducible formation of complex shell architectures with improved moisture and oxygen resistance.

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 quantum dots exhibit improved reliability and longer luminescent life due to enhanced resistance to moisture and oxygen, resulting in better performance in light-emitting devices.

Implementation Method 1

providing a shell precursor solution to the core solution to form a quantum dot precursor solution

Methodology Applied

Scientific EffectSolution mixing:

Implementation Method 2

heating the quantum dot precursor solution to synthesize quantum dots

Methodology Applied

Scientific EffectThermal synthesis: Heating

Data Source

PatentUS20230279291A1Quantum dot, forming method thereof and light-emitting device including the same

Publication Date: 2023.09.07 ENNOSTAR CORP

AI summary

A quantum dot is disclosed. The quantum dot includes: a core, a first shell, and a second shell. The first shell is discontinuously distributed around the core surface. The second shell is between the core and the first shell and encapsulates the core. The second shell has an irregularly shaped outer surface.