OLED Host Compound Reducing Exciton Annihilation

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Solution Overview

Problem

Existing organic light emitting diodes (OLEDs) face reduced light emission efficiency due to carrier injection loss, non-luminescent exciton formation, and triplet-triplet annihilation, which complicates their structure and manufacturing process.

Innovation Solution

An OLED structure featuring a compound represented by Formula 1 as a host in the light emitting layer, allowing for efficient hole transport and exciton formation without additional layers, thereby simplifying the manufacturing process and enhancing light emission efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a segmented structure with multiple layers (hole injection layer, hole transporting layer, electron transporting layer) is used, then charge injection and transport functions are improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvecharge injection efficiencyVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the hole transporting layer and electron transporting layer into a single organic material layer, eliminating the need for separate hole injection layer and hole transporting layer. This merging reduces the number of layers from 5-6 layers to 3 layers, simplifying the device structure while maintaining charge injection and transport functions through the dual-transport capability of the organic material layer.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The organic material layer is designed to perform multiple functions simultaneously: it serves as both the hole transporting layer and electron transporting layer, replacing the need for separate specialized layers. This multi-functional design reduces device complexity while maintaining the reliability of charge injection and transport processes.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Loss of energy

If additional layers (light emitting layer, electron transporting layer) are added to improve light emission efficiency, then light emission efficiency is improved, but manufacturing process complexity increases

Engineering Contradiction:
Improvelight emission efficiencyVSAvoidmanufacturing process simplicity
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The patent merges the light emitting layer and electron transporting layer with the hole transporting layer into a single integrated organic material layer. This eliminates the need for separate electron transporting layer and reduces manufacturing steps, simplifying the fabrication process while maintaining high light emission efficiency through optimized material composition and structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The organic material layer is designed to simultaneously perform light emission, electron transport, and hole transport functions. By using materials with appropriate energy levels and dual-transport capabilities, the single layer achieves the functionality of multiple layers, reducing manufacturing complexity while improving light emission efficiency.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Device complexity

If triplet-triplet annihilation and non-luminescent exciton formation are allowed to occur, then device structure remains simple, but light emission efficiency is significantly reduced

Engineering Contradiction:
Improvestructure simplicityVSAvoidlight emission efficiency
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent optimizes the energy level parameters and material composition of the organic material layer to minimize triplet-triplet annihilation and non-luminescent exciton formation. By carefully selecting materials with appropriate HOMO and LUMO levels and using optimal dopant concentrations, the device achieves high light emission efficiency while maintaining a simple three-layer structure.

Inventive Principle:
Principle #35Parameter changes

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 proposed OLED structure improves light emission efficiency and extends the service life by balancing charge transfer and reducing exciton annihilation, achieved through the use of a compound with hole transporting characteristics as a host in the light emitting layer.

Implementation Method 1

the light emitting layer comprises a host comprising a compound represented by the following Formula 1 and a dopant to transport holes injected from the first electrode through a hole transporting layer to the light emitting layer without energy barrier

Methodology Applied
Scientific EffectHole transport: Conduction (electrical)

Implementation Method 2

An organic light emitting diode is an electric diode that emits light through electric current by applied voltage

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP2746361B1Organic light-emitting diode
Publication Date: 2016.08.17 LG CHEM LTD
  • EP2746361B1 patent drawingFigure 1~2
  • EP2746361B1 patent drawingFigure 3~4
  • EP2746361B1 patent drawingFigure 5~6

AI summary

The present invention provides an organic light emitting diode comprising a first electrode, a second electrode and an organic material layer of one or more layers disposed between the first electrode and the second electrode, in which the organic material layer comprises a light emitting layer, an organic material layer comprising the compound represented by Formula 1 is comprised between the first electrode and the light emitting layer, and the light emitting layer comprises a host comprising the compound represented by Formula 1 and a dopant.