OLED Coating Compound for Thermal Stability and Charge Alignment

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Solution Overview

Problem

Existing organic light emitting devices face challenges with materials that lack thermal stability, efficient charge transfer, chemical stability, and proper band gap and energy level alignment, leading to high driving voltage, low efficiency, and short device lifetime.

Innovation Solution

A compound represented by Chemical Formula 1, which includes a pyrenyl group dimer with amine groups on both sides, is used in a coating composition for organic material layers, allowing for solution processing and enhancing solubility, processability, and light emission efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If NPB is used as hole transfer layer material, then device can be manufactured, but glass transition temperature is 100°C or lower causing difficulty in high current applications

Engineering Contradiction:

Improveglass transition temperatureVSAvoidthermal stability

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The patent modifies the molecular structure of hole transfer materials by introducing rigid aromatic groups (pyrene, triphenylene) and specific substituents to increase glass transition temperature from 100°C to above 150°C, thereby improving thermal stability for high current applications

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent develops composite organic materials combining multiple functional groups (amine, pyrene, triphenylene) within single molecules to achieve both high thermal stability and proper charge transport properties that cannot be obtained with conventional materials

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If PEDOT:PSS is used as hole transfer material, then solution coating method can be used, but LUMO energy level is lower than light emitting layer causing efficiency and lifetime problems

Engineering Contradiction:

Improvesolution processabilityVSAvoidenergy level alignment

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent designs organic hole transfer materials with specifically tuned HOMO and LUMO energy levels through molecular structure optimization, ensuring proper energy level alignment with light emitting layers while maintaining solution processability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces organic hole transfer materials as intermediary layers between PEDOT:PSS and light emitting layers, mediating charge transport while providing proper energy level alignment and preventing direct contact between PEDOT:PSS and light emitting layer materials

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If materials with high charge mobility are used, then exciton formation is maximized, but material deformation caused by moisture or oxygen increases

Engineering Contradiction:

Improvecharge mobilityVSAvoidchemical stability

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The patent develops composite molecules incorporating rigid aromatic cores (pyrene, triphenylene) with amine functional groups, achieving high charge mobility through conjugated structures while the rigid cores provide resistance to moisture and oxygen induced deformation

Inventive Principle:

Principle #40Composite materials

4Reliability

If complex compounds are used to achieve proper band gap and energy level, then charge transfer efficiency is improved, but device complexity increases

Engineering Contradiction:

Improvecharge transfer efficiencyVSAvoidmaterial complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces functional groups (amine, pyrene, triphenylene) at specific positions within molecular structures to locally provide charge transport capability and proper energy levels, simplifying overall material design compared to fully complex compounds

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

The compound enables low driving voltage, high light emission efficiency, and extended device lifetime by improving solubility, processability, and stability, suitable for large area devices.

Implementation Method 1

Methodology Applied

Scientific EffectSolubility enhancement:

Implementation Method 2

An organic light emission phenomenon is one of examples converting a current to visible light by an internal process of specific organic molecules. When an organic material layer is placed between an anode and a cathode and a current is applied between the two electrodes, electrons and holes are injected to the organic material layer from the cathode and the anode, respectively. The holes and the electrons injected to the organic material layer recombine to form excitons, and light emits when these excitons fall back to the ground state

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP3578553B1Compound, coating composition comprising same, and organic light emitting element comprising same

Publication Date: 2026.03.18 LG CHEM LTD

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AI summary

The present disclosure relates to a compound of Chemical Formula 1, a coating composition including the same, and an organic light emitting device including the same.