Organic Electroluminescent Device Hole Transport Layer Compound

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Solution Overview

Problem

Current organic electroluminescent devices face challenges in reducing driving voltage and enhancing efficiency and lifetime, particularly in the context of increasing display device sizes and the need for more efficient power consumption and longer durability.

Innovation Solution

The development of a novel organic electroluminescent device incorporating a specific compound represented by Chemical Formula 1, which is integrated into a hole transport auxiliary layer, along with other layers such as a hole injection layer, hole transport layer, electron transport layer, and electron injection layer, to optimize charge transport and emission efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional organic electroluminescent devices are used, then the device structure is simple, but the driving voltage is high and efficiency and lifetime are poor

Engineering Contradiction:

Improvedevice lifetimeVSAvoiddevice structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The device is divided into multiple functional layers including hole injection layer, hole transport layer, emission layer, electron transport layer, and electron injection layer. Each layer is optimized independently with specific compounds to achieve overall performance improvement while managing complexity through functional segmentation

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs composite material structures where the hole transport layer contains compounds of Formula 1 combined with specific substituents (Ar1-Ar7, R1-R5), and the emission layer uses host-guest composite systems with phosphorescent or fluorescent dopants, achieving enhanced reliability through material composition optimization

Inventive Principle:

Principle #40Composite materials

2Stress or pressure

If conventional organic electroluminescent devices are used, then the device structure is simple, but the driving voltage is high

Engineering Contradiction:

Improvedriving voltageVSAvoiddevice structure

Core Design Contradiction:

Stress or pressureVSDevice complexity

Solution Approach 1:

Specific layers are optimized with particular compounds having designated properties: the hole transport layer uses compounds of Formula 1 with specific aryl groups for optimal hole mobility and voltage characteristics, while the emission layer uses specific host-guest combinations for efficient exciton management, achieving localized optimization to reduce overall driving voltage

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent systematically varies molecular parameters including substituent types (Ar1-Ar7), chain lengths (k, l, m), and compound structures to optimize charge transport properties and energy levels, thereby reducing driving voltage through parameter optimization rather than structural simplification

Inventive Principle:

Principle #35Parameter changes

3Productivity

If conventional organic electroluminescent devices are used, then the device structure is simple, but the efficiency is poor

Engineering Contradiction:

Improvedevice efficiencyVSAvoiddevice structure

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The hole transport layer compounds of Formula 1 act as intermediaries facilitating efficient charge transport between the hole injection layer and emission layer, while the emission layer uses host-guest systems where the host material mediates exciton formation and energy transfer to the dopant, achieving high efficiency through intermediary optimization

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces simple sequential charge transport with optimized multi-layer electronic transport systems using compounds with specific HOMO-LUMO levels, replacing less efficient charge transport mechanisms with quantum-mechanically optimized electron and hole transport pathways

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 an organic electroluminescent device with lowered driving voltage, improved efficiency, and extended lifetime, as demonstrated by the increased LT95 values in the experimental examples compared to comparative devices.

Implementation Method 1

electrons and holes are paired to form excitons when charges are injected into a light emitting layer formed between a first electrode and a second electrode. Thus, energy of the excitons may be converted to light

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS11545630B2Compound and organic electroluminescent device comprising the same

Publication Date: 2023.01.03 LG DISPLAY CO LTD

AI summary

Organic electroluminescent devices with lowered driving voltages, and enhanced efficiencies and lifetimes are provided.