Terphenylene-Dibenzothiophene Hosts for OLED Stability

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Solution Overview

Problem

Current phosphorescent organic light-emitting devices (OLEDs) face challenges in achieving stable and efficient performance due to limitations in host materials, which affect the electron/hole transport balance and device stability.

Innovation Solution

Development of novel compounds containing terphenylene connected to dibenzothiophene, dibenzofuran, or dibenzoselenophene as hosts in phosphorescent OLEDs, which improve the electron/hole transport balance and stability by incorporating specific substituents and structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional host materials are used in phosphorescent OLEDs, then the device structure is simpler, but the device stability and electron-hole transport balance are insufficient

Engineering Contradiction:

Improvedevice stabilityVSAvoidhost material structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent modifies the host material molecular structure by changing chemical parameters - specifically incorporating dibenzothiophene, dibenzofuran, or dibenzoselenophene units with specific substituents (alkyl, alkoxy, halogen, etc.) to optimize electron-hole transport balance and device stability while maintaining structural feasibility for manufacturing

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates composite host materials by combining multiple functional units (terphenylene core with dibenzothiophene/dibenzofuran/dibenzoselenophene) to achieve synergistic effects that improve both device stability and transport balance, resolving the contradiction between performance improvement and structural complexity

Inventive Principle:

Principle #40Composite materials

2Duration of action of stationary object

If conventional host materials are used in phosphorescent OLEDs, then the material synthesis is simpler, but the device lifetime is reduced

Engineering Contradiction:

Improvedevice lifetimeVSAvoidmaterial synthesis

Core Design Contradiction:

Duration of action of stationary objectVSEase of manufacture

Solution Approach 1:

The patent extends device lifetime by modifying chemical parameters of host materials - incorporating specific heterocyclic units (dibenzothiophene, dibenzofuran, dibenzoselenophene) and substituents that enhance molecular stability and reduce degradation, accepting increased synthetic complexity as a necessary trade-off for improved device lifetime

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses specific host material structures as intermediaries that facilitate balanced electron-hole transport and reduce degradation pathways, thereby extending device lifetime despite more complex synthesis requirements

Inventive Principle:

Principle #24Intermediary (Mediator)

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 use of these novel compounds as hosts in OLEDs results in enhanced device stability and performance, with devices exhibiting nearly twice the stability of comparative devices, as demonstrated by extended lifetime at constant luminance levels.

Implementation Method 1

phosphorescent organic light-emitting devices (OLEDs)

Methodology Applied

Scientific EffectPhosphorescence: Phosphorescence

Data Source

PatentUS9190620B2Organic electroluminescent materials and devices

Publication Date: 2015.11.17 UNIVERSAL DISPLAY CORP

AI summary

A novel compound containing terphenylene connected to dibenzothiophene, dibenzofuran or dibenzoselenophene that can be used as hosts in phosphorescent organic light-emitting device is disclosed.