Metal-Complex Semiconductor Layer for Stable Low-Voltage OLED Anodes
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Solution Overview
Problem
Existing organic electronic devices face challenges in achieving improved operating voltage, voltage stability, and current efficiency, particularly due to the performance limitations of their semiconductor layers, including the use of metal complexes.
Innovation Solution
The semiconductor layer in the organic electronic device comprises a metal complex with a specific anode structure, featuring a first anode sub-layer with a work function between 4 and 6 eV and a transparent conductive oxide sub-layer, along with a metal cation and an anionic ligand containing at least four covalently bound atoms, and is free of copper phthalocyanine, enhancing the performance of the device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional organic semiconductor layers are used in OLEDs, then the device structure is simple, but the operating voltage is high and current efficiency is low
Solution Approach 1:
The patent employs composite materials by introducing a semiconductor layer comprising a metal complex (such as copper(I) complex with specific ligands like N-heterocyclic carbene and phosphine) between the anode and photoactive layer. This composite semiconductor layer combines the metal complex with organic ligands to achieve optimized charge injection and transport properties, thereby reducing operating voltage while maintaining device structural simplicity
Solution Approach 2:
The patent changes key material parameters by selecting specific metal complexes with controlled ligand compositions and ratios. By adjusting the metal-to-ligand ratio, ligand types (such as combining N-heterocyclic carbene with phosphine), and molecular structure parameters, the semiconductor layer achieves optimal HOMO level alignment with the anode, improving hole injection efficiency and reducing operating voltage
2Device complexity
If conventional organic semiconductor layers are used in OLEDs, then the device structure is simple, but the current efficiency is low
Solution Approach 1:
The semiconductor layer uses a composite metal complex system where copper(I) is coordinated with specific ligands including N-heterocyclic carbene and phosphine. This composite structure enables synergistic effects that enhance charge carrier generation and transport, significantly improving current efficiency while avoiding the need for complex multi-layer device structures
Solution Approach 2:
The patent implements a streamlined device architecture by placing the semiconductor layer directly between the anode and photoactive layer, skipping traditional multiple intermediate layers (such as separate hole injection layer and electron transport layer). This 'skipping' approach maintains structural simplicity while the metal complex semiconductor layer performs multiple functions simultaneously, achieving high current efficiency
3Ease of manufacture
If conventional semiconductor layers are used, then the device is easy to manufacture, but the voltage stability over time is poor
Solution Approach 1:
The patent optimizes manufacturing ease by using metal complexes that can be deposited using conventional vacuum deposition techniques. The ligand composition parameters are specifically designed to ensure stable molecular structures with high thermal and chemical stability, preventing degradation during device operation and maintaining voltage stability over time
Solution Approach 2:
The patent employs stable metal complex compounds that resist degradation and decomposition during device operation. The specific ligand combinations (N-heterocyclic carbene, phosphine) create robust coordination structures that maintain their properties over time, ensuring long-term voltage stability without requiring complex protective structures or frequent replacement
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 results in superior operating voltage, improved voltage stability, and higher current efficiency compared to conventional devices, addressing the performance limitations of existing technologies.
Implementation Method 1
holes injected from the anode move to the EML, via the HIL and HTL, and electrons injected from the cathode move to the EML, via the ETL
Implementation Method 2
Performance of an organic light emitting diode may be affected by characteristics of the organic semiconductor layers, such as the hole injection layer, and among them, may be affected by characteristics of the compounds contained in the organic semiconductor layer
Data Source
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AI summary
The present invention relates to an organic electronic device comprising an anode layer, a cathode layer, at least one photoactive layer, and a semiconductor layer, wherein the photoactive layer and the semiconductor layer are arranged between the anode layer and the cathode layer, wherein the semiconductor layer is arranged between the photoactive layer and the anode layer; wherein the anode layer comprises a first anode sub-layer and a second anode sub-layer, wherein the first anode sub-layer comprises a first metal having a work function in the range of ≥ 4 and ≤ 6 eV, and the second anode sub-layer comprises a transparent conductive oxide (TCO); wherein the second anode sub-layer is arranged closer to the semiconductor layer than the first anode sub layer; wherein the semiconductor layer comprises at least one metal complex, wherein the metal complex comprises a metal cation and at least one anionic ligand, wherein the anionic ligand comprises at least four covalently bound atoms, and wherein the semiconductor layer comprises the metal complex in a range of ≥31 percent by weight to ≤100 percent by weight, based on the total weight of the semiconductor layer.