Pyrene Host Charge Generation Layer for White OLED Electron Balance

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Solution Overview

Problem

Current white OLED devices face inefficiencies due to poor electron injection from the charge generation layer to the electron transport layer, leading to imbalanced electron and hole distribution, which reduces light emission efficiency and increases driving voltage.

Innovation Solution

Incorporating a charge generation layer with at least two hosts, including a pyrene compound, to facilitate electron injection and transfer by creating various energy levels, thereby improving electron balance and reducing driving voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electron injection is improved, then electron-hole balance is improved, but device complexity increases

Engineering Contradiction:
Improveelectron-hole balanceVSAvoidcharge generation layer structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent achieves improved electron-hole balance by adjusting energy level parameters of the host materials rather than adding complex structural elements. The LUMO level range of 2.0-3.5 eV provides multiple transfer pathways that improve electron injection and balance without increasing device structural complexity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The charge generation layer is designed with specific local properties - using hosts with particular energy levels and molecular characteristics - to optimize electron transfer. This localized optimization of material properties achieves improved electron-hole balance without requiring complex overall device architecture.

Inventive Principle:
Principle #3Local quality

2Reliability

If multiple hosts with different energy levels are used, then electron transfer is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improveelectron transferVSAvoidhost material composition
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent defines a specific energy level range (LUMO: 2.0-3.5 eV) for host materials, providing clear manufacturing specifications. This parameter-based approach allows manufacturers to select from various materials within the defined range, achieving consistent electron transfer performance without requiring ultra-precise composition control.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The charge generation layer uses hosts with comparable molecular characteristics and energy level ranges, creating a homogeneous system in terms of material properties. This homogeneity simplifies manufacturing processes and quality control while still providing multiple electron transfer pathways through the energy level variations within the defined range.

Inventive Principle:
Principle #33Homogeneity

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 a pyrene compound in the charge generation layer enhances electron injection and transfer, resulting in higher emission efficiency and lower driving voltage for white OLED devices.

Implementation Method 1

the transfer of electrons from the charge generation layer to an electron transport layer is not smooth

Methodology Applied
Scientific EffectElectron injection:

Implementation Method 2

Incorporating a charge generation layer with at least two hosts, including a pyrene compound, to facilitate electron injection and transfer by creating various energy levels

Methodology Applied
Scientific EffectEnergy levels:

Implementation Method 3

the OLED devices are a type of devices that emit light as electrons and holes are paired and extinguished, when a charge is injected into an organic light emitting layer

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 4

the use of a pyrene compound in the charge generation layer enhances electron injection and transfer

Methodology Applied
Scientific EffectElectron transfer:

Data Source

PatentEP3010056B1Organic light emitting diode device
Publication Date: 2019.04.17 LG DISPLAY CO LTD
  • EP3010056B1 patent drawingFigure 1
  • EP3010056B1 patent drawingFigure 2
  • EP3010056B1 patent drawingFigure 3

AI summary

An organic light emitting diode device (100) is disclosed. There is an organic light emitting diode device (100) that comprises a first light emitting part (ST1) between an anode (110) and a cathode (220), the first light emitting part (ST1) including a first light emitting layer (140), a second light emitting part (ST2) comprising a second light emitting layer (190) on the first light emitting part (ST1), and a first charge generation layer (160) between the first light emitting part (ST1) and the second light emitting part (ST2), the first charge generation layer (160) comprising at least two hosts, and at least one of the at least two hosts including a pyrene compound.