Organic Electroluminescent Host Compounds for Thermal Stability

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Solution Overview

Problem

Conventional organic electroluminescent devices using phosphorescent host materials suffer from low glass transition temperatures, poor thermal stability, high driving voltage, and unsatisfactory power and luminous efficiency, as well as short operating lifespan.

Innovation Solution

Development of specific organic electroluminescent compounds represented by formulas 1 and 2, which serve as host materials with improved molecular structure and properties, enhancing luminous efficiency, current efficiency, and power efficiency, and extending the operating lifespan of organic EL devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If conventional phosphorescent host materials (CBP, BCP, BAlq) are used in organic EL devices, then good light-emitting characteristics are achieved, but glass transition temperature is low and thermal stability is poor

Engineering Contradiction:

Improvelight-emitting characteristicsVSAvoidglass transition temperature and thermal stability

Core Design Contradiction:

Illumination intensityVSTemperature

Solution Approach 1:

The patent applies parameter changes by modifying the molecular structure of host materials from conventional phosphorescent types to new compounds with formulas 1 and 2, which have higher glass transition temperatures and superior thermal stability while maintaining electroluminescence performance

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials by creating new host material compounds that integrate multiple functional groups and structural features, achieving both thermal stability and good light-emitting characteristics simultaneously

Inventive Principle:

Principle #40Composite materials

2Power

If conventional phosphorescent host materials are used, then current efficiency is improved, but driving voltage becomes high and power efficiency deteriorates

Engineering Contradiction:

Improvecurrent efficiencyVSAvoidpower efficiency and driving voltage

Core Design Contradiction:

PowerVSUse of energy by stationary object

Solution Approach 1:

The patent changes the electrical parameters of the host materials by developing new compounds with optimized HOMO-LUMO energy levels and charge transport properties, achieving low driving voltage and high power efficiency while maintaining current efficiency

Inventive Principle:

Principle #35Parameter changes

3Illumination intensity

If conventional phosphorescent host materials are used, then light-emitting characteristics are enhanced, but operating lifespan becomes short

Engineering Contradiction:

Improvelight-emitting characteristicsVSAvoidoperating lifespan

Core Design Contradiction:

Illumination intensityVSDuration of action of stationary object

Solution Approach 1:

The patent modifies the chemical and physical parameters of host materials by introducing new molecular structures with formulas 1 and 2, which exhibit superior electrochemical stability, higher thermal resistance, and improved morphological stability, thereby extending device operating lifespan

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies beforehand cushioning by designing host materials with inherent resistance to degradation mechanisms such as thermal decomposition, oxidation, and morphological changes, providing long-term stability and extended device lifespan

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

4Productivity

If conventional phosphorescent host materials are used, then light-emitting efficiency is improved, but thermal stability and electrochemical stability are insufficient

Engineering Contradiction:

Improveluminous efficiencyVSAvoidthermal stability and electrochemical stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent employs composite materials by synthesizing new host compounds with formulas 1 and 2 that integrate multiple stabilizing structural features, achieving high luminous efficiency alongside superior thermal and electrochemical stability

Inventive Principle:

Principle #40Composite materials

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 new compounds provide organic EL devices with higher luminous efficiency, improved current and power efficiency, reduced electric power consumption, and high-color purity, while maintaining thermal stability and long operating lifespan.

Implementation Method 1

The organic light-emitting compound moves into an excited state by the energy and emits light from energy when the organic light-emitting compound returns to the ground state from the excited state

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS9698355B2Organic electroluminescent compounds and organic electroluminescent device comprising the same

Publication Date: 2017.07.04 DUPONT SPECIALTY MATERIALS KOREA LTD

AI summary

The present invention relates to a novel organic electroluminescent compound and an organic electroluminescent device comprising the same. The organic electroluminescent compound of the present invention has high luminous efficiency, and thus can be used as a host in a light-emitting layer; and an organic electroluminescent device comprising the organic electroluminescent compounds of the present invention has long operating lifespan, provides improved current efficiency and power efficiency, and gives colors having high purity.