OLED Quantum Dot Hole Transport Layer Energy Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing organic light emitting diode (OLED) display technologies face challenges in achieving balanced hole and electron injection, leading to instability and reduced emission efficiency due to significant energy level differences between the hole transport and emission layers.
Innovation Solution
Incorporating quantum dots with a core/shell structure and p-doped or n-doped Group I-VI, II-VI, or III-VI compounds in the hole and electron transport layers, respectively, to minimize energy level differences and enhance injection efficiency, along with an emission layer containing similar quantum dots for balanced charge injection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional hole transport layers are used, then device structure is simple, but energy level difference between hole transport layer and emission layer causes unbalanced charge injection and reduced emission efficiency
Solution Approach 1:
The patent changes the energy level parameters of the hole transport layer by using p-doped Group I-VI, II-VI, or III-VI compounds, which have higher HOMO levels that better match the emission layer, thereby improving charge injection balance without significantly increasing structural complexity
Solution Approach 2:
The patent employs composite material structures where the hole transport layer is formed using doped compound semiconductors (such as p-ZnO, p-CdS, p-InP) that combine multiple elements to achieve optimized energy level alignment and improved charge transport properties
2Reliability
If quantum dots with core/shell structure are used, then emission efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
The patent optimizes the size parameters of quantum dots (5-50 nm diameter) and their compositional parameters (core/shell material combinations) to achieve high emission efficiency while maintaining compatibility with existing manufacturing processes
Solution Approach 2:
The patent applies core/shell structure where the core provides quantum confinement for light emission and the shell provides protective and functional properties, with each layer having optimized local composition and thickness to balance performance and manufacturability
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 ensures balanced hole and electron injection, improving the stability and emission efficiency of the organic light emitting element by minimizing energy level disparities and optimizing charge transport.
Implementation Method 1
The excitons emit energy in the form of light is emitted
Implementation Method 2
The hole transport layer includes at least one of a p-doped Group I-VI compound, a p-doped Group II-VI compound, and a p-doped Group III-VI compound
Implementation Method 3
The quantum dots may each have a core/shell structure in which the shell covers the core
Data Source
AI summary
An organic light emitting element includes a first electrode a second electrode that faces the first electrode, an emission layer between the first electrode and the second electrode, the emission layer including quantum dots, and a hole transport layer between the first electrode and the emission layer. The quantum dots include at least one of a Group I-VI compound, a Group II-VI compound, and a Group III-VI compound. The hole transport layer includes at least one of a p-doped Group I-VI compound, a p-doped Group II-VI compound, and a p-doped Group III-VI compound.