OLED Electron Transport Layer Using Specific Organic Compounds

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Solution Overview

Problem

Organic light emitting diodes (OLEDs) emitting blue fluorescent light face challenges in achieving high light emission efficiency and long lifespan due to high exciton energy, which leads to energy stress and reduced device lifespan, and existing solutions often require additional layers and increased driving voltage.

Innovation Solution

Incorporating a specific organic material layer with compounds like Compound 13, 56, and 100 between the cathode and light emitting layer, which acts as an electron transfer or injection layer, controlling electron transfer to induce exciton formation within the light emitting layer, thereby minimizing hole accumulation and extending device lifespan without the need for a separate hole blocking layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If blue fluorescent light is emitted with high exciton energy, then light emission efficiency is improved, but device lifespan is reduced due to energy stress

Engineering Contradiction:

Improvelight emission efficiencyVSAvoiddevice lifespan

Core Design Contradiction:

Use of energy by moving objectVSDuration of action of stationary object

Solution Approach 1:

The patent introduces a specific organic compound (Compound 1 or Compound 2) as an intermediary material in the electron transport layer between the cathode and light emitting layer. This intermediary compound mediates electron transfer to induce exciton formation within the light emitting layer, thereby reducing hole accumulation and energy stress at the interface, which extends device lifespan while maintaining high light emission efficiency

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the chemical and electronic parameters of the electron transport layer by using specific compounds with defined molecular structures (Compounds 1 and 2). These parameter changes in the organic material layer optimize electron transfer characteristics, enabling controlled exciton formation and reduced energy stress, thus resolving the contradiction between efficiency and lifespan

Inventive Principle:

Principle #35Parameter changes

2Duration of action of stationary object

If a separate hole blocking layer is added to control hole accumulation, then device lifespan is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improvedevice lifespanVSAvoidnumber of layers

Core Design Contradiction:

Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The patent makes the electron transport layer multi-functional by selecting organic compounds (Compound 1 or Compound 2) that simultaneously perform electron transport and hole blocking functions. This eliminates the need for a separate hole blocking layer, reducing device complexity while maintaining extended device lifespan through controlled hole accumulation

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the functions of the electron transport layer and hole blocking layer into a single organic material layer. By combining these functions in one layer using specific organic compounds, the device structure is simplified while still achieving the desired control over charge carrier accumulation to extend device lifespan

Inventive Principle:

Principle #5Merging (Combining)

3Use of energy by moving object

If additional layers are added to control electron transfer, then light emission efficiency is improved, but driving voltage increases

Engineering Contradiction:

Improvelight emission efficiencyVSAvoiddriving voltage

Core Design Contradiction:

Use of energy by moving objectVSPower

Solution Approach 1:

The patent changes the electronic parameters of the electron transport layer by using specific organic compounds with optimized molecular structures (Compounds 1 and 2). These parameter changes enable efficient electron transfer and exciton formation without requiring additional layers, thus maintaining high light emission efficiency while avoiding increased driving voltage

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

This configuration enhances the efficiency and lifespan of OLEDs by maintaining high light emission efficiency while reducing driving voltage and eliminating the need for additional layers, resulting in a simpler and more cost-effective device structure.

Implementation Method 1

the organic material layer includes one of the following compounds: Compound 1 or Compound 2... acts as an electron transfer or injection layer, controlling electron transfer to induce exciton formation within the light emitting layer

Methodology Applied

Scientific EffectElectron transfer: Conduction (electrical)

Implementation Method 2

When an organic material layer is placed between an anode and a cathode and a voltage is applied between the two electrodes, electrons and holes are injected to the organic material layer from the cathode and the anode, respectively. The electrons and the holes injected to the organic material layer are recombined to form excitons, and light emits when these excitons fall back to the ground state

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP3222695B1Organic light emitting diode

Publication Date: 2021.06.02 LG CHEM LTD

Figure 1

AI summary

The present specification relates to an organic light emitting diode.