Doped Matrix Electrode for OLED Charge Injection

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Solution Overview

Problem

In organic light-emitting diodes (OLEDs), the use of wet-chemical deposition methods for electrode materials like silver nanowires can lead to inhomogeneous charge carrier injection due to the risk of solubilizing underlying layers, affecting the uniformity of charge transfer and luminescence patterns, especially in thin layers.

Innovation Solution

A doped matrix material containing metal nanowires is used as a multifunctional electrode layer that acts as both an electrode and a charge carrier injection/transport layer, eliminating the need for separate hole injection and transport layers, applied in a single wet-chemical step to ensure uniform charge carrier injection and detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wet-chemical deposition is used to apply silver nanowires as electrode material, then transparency and conductivity can be adjusted through concentration, but the underlying layers may be solubilized causing inhomogeneous charge carrier injection and luminescence patterns

Engineering Contradiction:

Improvecharge carrier injection uniformityVSAvoidlayer solubilization

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A solvent-resistant underlayer is introduced between the substrate and the active layer to serve as a protective intermediary. This underlayer prevents the solubilization of underlying layers during wet-chemical deposition of subsequent layers, thereby eliminating the harmful effect of layer dissolution while maintaining the benefits of wet-chemical processing for transparent and conductive electrode materials.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If separate hole injection layer and hole transport layer are deposited in further method steps, then charge carrier injection and transport functions are achieved, but the risk of solubilizing underlying layers increases and interface definition is compromised

Engineering Contradiction:

Improveproduction process simplificationVSAvoidinterface definition

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The hole injection layer and hole transport layer are merged into a single multifunctional layer that performs both charge carrier injection and transport functions. This consolidation reduces the number of deposition steps, minimizes the risk of solubilizing underlying layers, and maintains well-defined interfaces while achieving the required charge carrier management functions.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

A single layer is designed to fulfill multiple functions: serving as both the hole injection layer and the hole transport layer. This multifunctional approach simplifies the manufacturing process by reducing the number of separate deposition steps while maintaining precise interface definition and effective charge carrier management.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If thin layers with thickness of only a few nanometers are used, then charge carrier injection effectiveness is improved, but inhomogenities become discernable in the luminescence pattern and charge transfer uniformity is impaired

Engineering Contradiction:

Improvecharge transfer uniformityVSAvoidluminescence pattern uniformity

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The solvent-resistant underlayer provides localized protection at the critical interface region where solubilization would occur. By concentrating the protective function at this specific location, the design enables the use of thin active layers for effective charge carrier injection while preventing the formation of inhomogeneities that would manifest as luminescence pattern defects.

Inventive Principle:

Principle #3Local quality

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 enhances the uniformity and effectiveness of charge carrier injection into the active layer, simplifies the production process, reduces material costs, and minimizes the risk of layer solubilization, resulting in improved performance and reduced inhomogeneities in the luminescence pattern.

Implementation Method 1

The metal nanowires form an electrically conductive network in the first electrode layer. Such an electrode is referred to as percolation electrode.

Methodology Applied

Scientific EffectPercolation:

Implementation Method 2

the doped matrix material, with the metal nanowires contained therein, acts as a charge carrier transport material and/or a charge carrier injection material

Methodology Applied

Scientific EffectCharge carrier injection:

Implementation Method 3

the doped matrix material, with the metal nanowires contained therein, acts as a charge carrier transport material and/or a charge carrier injection material

Methodology Applied

Scientific EffectCharge carrier transport:

Data Source

PatentUS11056660B2Organic optoelectronic component and method for producing the same

Publication Date: 2021.07.06 DOLYA HOLDCO 5 LTD

AI summary

The invention relates to an organic optoelectronic component (10) comprising a first electrode layer (2), having a doped matrix material and metal nanowires, an organic active layer (3), which is suitable for emitting or detecting electromagnetic radiation, and a second electrode layer (6). The organic active layer (3) is directly adjacent to the first electrode layer (2). The invention further relates to a method for producing the organic optoelectronic component (10).