Quantum Dot Core-Shell Structure for Balanced Carrier Injection

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Solution Overview

Problem

In quantum dot light-emitting diode (QLED) devices, the deep valence band of quantum dots leads to insufficient hole injection, resulting in uneven electron and hole injection, affecting efficiency and service life, and the complexity of multiple functional layers complicates the preparation process with uncontrollable solvent interactions.

Innovation Solution

A quantum dot with a core-shell structure where the outermost shell includes both electron transport and hole transport materials, allowing for efficient electron and hole injection and simplifying the device structure by eliminating the need for separate electron and hole transport layers, achieved through partial oxidation and ion exchange processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If ZnO material is introduced to the electron transport layer to improve electron transport efficiency, then electron transport efficiency is improved, but hole injection becomes insufficient due to deep valence band of quantum dots, resulting in uneven electron and hole injection

Engineering Contradiction:

Improveelectron transport efficiencyVSAvoidhole injection balance

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The patent combines electron transport material and hole transport material into a single outermost shell structure surrounding the quantum dot core. This merged structure allows both electron and hole transport functions to be integrated at the quantum dot interface, ensuring balanced carrier injection without requiring separate functional layers that would create interface mismatches and injection imbalance.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The outermost shell is designed to perform multiple functions simultaneously: it serves as both the electron transport layer and hole transport layer. By incorporating both electron transport material and hole transport material in the same shell, the structure achieves multi-functionality, eliminating the need for separate specialized layers and ensuring coordinated electron and hole injection.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If more functional layers are added to improve device performance, then device performance is improved, but process complexity and uncontrollability increase

Engineering Contradiction:

Improvedevice performanceVSAvoidpreparation process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent reduces the number of functional layers by merging the electron transport layer and hole transport layer into a single outermost shell. This consolidation simplifies the device structure from multiple separate layers to an integrated core-shell architecture, thereby reducing preparation process complexity while maintaining comprehensive transport functionality.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The outermost shell is designed as a multi-functional component that simultaneously provides electron transport, hole transport, and quantum dot protection functions. This multi-functionality eliminates the need for multiple specialized layers, simplifying both device structure and preparation process while maintaining or improving device performance.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If more functional layers are added to improve device performance, then device performance is improved, but solvent interaction control becomes more difficult

Engineering Contradiction:

Improvedevice performanceVSAvoidsolvent interaction control

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

By merging electron transport and hole transport functions into a single outermost shell, the patent reduces the number of material interfaces and solvent interaction points during preparation. This consolidation simplifies solvent interaction control compared to preparing multiple separate functional layers, each requiring independent solvent compatibility management.

Inventive Principle:

Principle #5Merging (Combining)

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 enhances the balance of electron and hole injection, improving the efficiency and extending the service life of QLED devices while simplifying the device structure and preparation process.

Implementation Method 1

a material of the outermost shell includes an electron transport material and a hole transport material

Methodology Applied

Scientific EffectElectron transport: Conduction (electrical)

Implementation Method 2

a material of the outermost shell includes an electron transport material and a hole transport material

Methodology Applied

Scientific EffectHole transport: Conduction (electrical)

Implementation Method 3

processing the original shell to form a shell structure surrounding the core structure

Methodology Applied

Scientific EffectOxidation: Oxidation

Implementation Method 4

achieved through partial oxidation and ion exchange processes

Methodology Applied

Scientific EffectIon exchange: Ion Exchange

Data Source

PatentUS20230383178A1Quantum dot and preparation method therefor, quantum dot light-emitting device, and display apparatus

Publication Date: 2023.11.30 BOE TECHNOLOGY GROUP CO LTD

AI summary

Disclosed are a quantum dot and a preparation method therefor, a quantum dot light-emitting device, and a display apparatus. The quantum dot includes a core structure and a shell structure that surrounds the core structure, wherein the material of the outermost shell in the shell structure includes an electron transport material and a hole transport material.