QLED Hole Injection Layer Composition for Lower Interface Barrier
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Solution Overview
Problem
Current quantum dot light emitting diodes (QLEDs) face a low hole injection rate due to a high interface energy level barrier between the hole injection layer and the anode, resulting from a common material mismatch, which hinders efficient carrier injection and device performance.
Innovation Solution
A hole injection layer with a specific multi-component structure, comprising a first metal oxide, a second metal oxide, and a metal, where the metal undergoes an oxidation-reduction reaction to form a third metal oxide, reducing the interface barrier and enhancing carrier transmission, is introduced. This structure includes a first sub-layer and a second sub-layer with a reaction layer in between, and can be further optimized with additional sub-layers and reaction layers, improving the contact with the anode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a common material is used for the hole injection layer and anode, then the manufacturing process is simple, but the interface energy level barrier is too high resulting in low hole injection rate
Solution Approach 1:
The hole injection layer uses a composite material consisting of MoO3 and Al, where MoO3 provides high work function to reduce interface energy level barrier and improve hole injection rate, while Al enhances electrical conductivity. This composite structure resolves the contradiction by achieving both good electrical properties and efficient hole injection without complicating the manufacturing process
Solution Approach 2:
The invention changes the material parameters of the hole injection layer by selecting specific materials with appropriate work functions and conductivities. By adjusting the composition ratio of MoO3 and Al, the interface energy level barrier is optimized to enable high hole injection rate while maintaining manufacturing simplicity
2Productivity
If the interface energy level barrier is reduced to improve hole injection, then the hole injection rate increases, but the device complexity increases due to material and structure optimization
Solution Approach 1:
The composite of MoO3 and Al in the hole injection layer achieves interface energy level optimization through material selection rather than complex multi-layer structures. This approach improves hole injection rate while keeping the device structure relatively simple and manageable
3Productivity
If a multi-component hole injection layer is used to improve carrier transmission, then the light emitting efficiency increases, but the manufacturing precision requirements increase
Solution Approach 1:
The MoO3-Al composite hole injection layer improves carrier transmission rate by combining materials with complementary properties: MoO3 for high work function and Al for high conductivity. The manufacturing precision is managed by controlling the mass ratio of Al to total materials within 5-20%, which is a achievable specification for standard deposition processes
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 improved hole injection layer increases the carrier transmission rate, leading to enhanced light emitting efficiency, reduced power consumption, and extended service life of the QLED device by achieving a more uniform electric and heat conduction.
Implementation Method 1
a metal M and a third metal oxide MOy, wherein 0≤y≤3, y is a natural number or a decimal... the metal undergoes an oxidation-reduction reaction to form a third metal oxide
Data Source
AI summary
The present disclosure provides a display panel and a display apparatus. The display panel includes a first electrode layer, an electron transport layer, a light emitting layer, a hole transport layer, a hole injection layer, and a second electrode layer, which are sequentially stacked, a material of the hole injection layer includes a first metal oxide and a second metal oxide, which contain the same metal element, the number of outermost electrons of the metal element in the first metal oxide is different from the number of outermost electrons of the metal in the second metal oxide. In addition, the hole injection layer further includes a metal M and a third metal oxide MOy, the third metal oxide MOy is formed by an oxidation-reduction reaction between the metal M and the first metal oxide. The hole injection layer may be of a single layer or a multi-layer structure.