Coating-Type Organic Electroluminescent Device with Integrated Electron Injection

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Solution Overview

Problem

Conventional coating-type organic electroluminescent devices face challenges in manufacturing cost reduction and efficiency, particularly in forming layers by coating methods that affect the performance and lifespan of the devices.

Innovation Solution

The solution involves forming a coating-type organic electroluminescent device with a first electrode, an emitting material layer, and an electron injection layer, where both the emitting material layer and the electron injection layer are formed by coating, allowing for the omission of a separate second electrode in some configurations, and using specific materials and solvents to enhance layer formation and electron injection efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a vapor deposition method is used to form all layers including electron injection layer, then manufacturing precision and device performance are improved, but manufacturing cost and process complexity increase

Engineering Contradiction:

Improvelayer formation precisionVSAvoidmanufacturing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent segments the manufacturing process into two distinct parts: (1) vapor deposition method for forming the electron injection layer and second electrode, and (2) coating method for forming the emitting material layer. This segmentation allows each method to be optimized for its specific function, achieving high precision where needed while reducing cost in less critical areas.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different manufacturing methods to different layers based on their specific requirements. The electron injection layer and second electrode receive the high-precision vapor deposition treatment, while the emitting material layer is formed using the lower-cost coating method. This local differentiation of manufacturing quality matches the functional importance of each layer.

Inventive Principle:

Principle #3Local quality

2Ease of manufacture

If coating method is used to form emitting material layer, then manufacturing cost is reduced, but layer formation consistency and device performance may deteriorate

Engineering Contradiction:

Improvemanufacturing costVSAvoidlayer formation consistency

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent introduces an electron injection layer as an intermediary between the emitting material layer and the second electrode. This intermediary layer, formed by vapor deposition, provides a high-quality interface that compensates for the lower precision of the coating method used for the emitting material layer, ensuring consistent device performance.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent uses a composite structure combining materials formed by different methods. The emitting material layer (coating) is combined with the electron injection layer (vapor deposition) to create a composite electrode structure that leverages the cost-effectiveness of coating while maintaining the precision and consistency of vapor deposition at critical interfaces.

Inventive Principle:

Principle #40Composite materials

3Reliability

If separate second electrode is included, then device structure and electron injection are improved, but device complexity and manufacturing steps increase

Engineering Contradiction:

Improveelectron injection efficiencyVSAvoidnumber of layers

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the electron injection layer and the second electrode into a single integrated layer structure. This merged layer performs both functions: injecting electrons into the emitting material layer and serving as the cathode electrode, thereby reducing device complexity while maintaining electron injection efficiency.

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 approach reduces manufacturing costs and improves the efficiency and lifespan of the organic electroluminescent devices by enabling consistent layer formation at atmospheric pressure, lowering turn-on voltage, and increasing current values, thus enhancing the overall performance of the devices.

Implementation Method 1

an electron injection layer facing the first electrode

Methodology Applied

Scientific EffectElectron injection:

Implementation Method 2

organic electroluminescent device

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 3

the emitting material layer and the electron injection layer are formable by coating

Methodology Applied

Scientific EffectCoating deposition: Deposition (physical)

Data Source

PatentUS10950827B2Coating-type organic electroluminescent device, and a display device and lighting device including the same

Publication Date: 2021.03.16 LG DISPLAY CO LTD

AI summary

The present disclosure relates to a coating-type organic electroluminescent device and a display device and a lighting device including the same. The present disclosure relates to an organic electroluminescent device in which an inter-electrode layer and at least one layer of a first electrode and a second electrode can be consistently manufactured at atmospheric pressure. The organic electroluminescent device includes a first electrode, an electron injection layer facing the first electrode, and an emitting material layer located between the first electrode and the electron injection layer, wherein the emitting material layer and the electron injection layer are formable by coating.