Amine-Based Hole Transport Material for OLED Driving Voltage Reduction

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Solution Overview

Problem

Current organic light-emitting devices face limitations in achieving high charge mobility and low driving voltage due to the energy level optimization of hole transport compounds, which affects the efficiency and lifespan of the devices.

Innovation Solution

Incorporating an amine-based compound with a specific structure, such as those represented by Formulae 1-1 to 1-6, in the hole transport region, which facilitates orbital delocalization and optimizes the highest occupied molecular orbital (HOMO) energy level for efficient hole transport, thereby reducing the driving voltage and enhancing device performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If conventional hole transport compounds are used in organic light-emitting devices, then device structure and operation are maintained, but charge mobility is limited and driving voltage remains high

Engineering Contradiction:
Improvecharge mobilityVSAvoiddriving voltage
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The patent applies parameter changes by modifying the molecular structure of hole transport compounds to achieve specific HOMO energy levels (5.6-6.2 eV) and charge mobility (10^-6 to 10^-3 cm²/Vs). This structural parameter optimization enables improved charge transport efficiency and reduced driving voltage without changing the fundamental device architecture

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials by combining the amine-based compound with specific substituents (Formulae 6-1 to 6-10, 6-12 to 6-18, and 6-27 to 6-34) to create optimized hole transport materials. These composite molecular structures achieve both high charge mobility and appropriate energy level alignment, resolving the contradiction between speed and energy consumption

Inventive Principle:
Principle #40Composite materials

2Reliability

If hole transport compounds with optimized energy levels are used, then charge mobility improves, but device complexity increases due to specific structural requirements

Engineering Contradiction:
Improvedevice efficiencyVSAvoidcompound structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent defines specific parameter ranges for HOMO energy level (5.6-6.2 eV) and charge mobility (10^-6 to 10^-3 cm²/Vs) to ensure reliable device performance. By establishing these quantitative criteria, the patent balances reliability requirements with manageable structural complexity in the hole transport compounds

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 use of these amine-based compounds in the organic light-emitting device leads to improved charge mobility, reduced power consumption, and extended lifespan by optimizing the energy levels for efficient hole transport and emission.

Implementation Method 1

Incorporating an amine-based compound with a specific structure, such as those represented by Formulae 1-1 to 1-6, in the hole transport region, which facilitates orbital delocalization and optimizes the highest occupied molecular orbital (HOMO) energy level for efficient hole transport

Methodology Applied
Scientific EffectOrbital delocalization:

Implementation Method 2

The carriers (e.g., holes and electrons) may recombine in the emission layer to produce excitons. Then, the excitons may transition from an excited state to a ground state, thereby releasing energy in the form of light.

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP3444241B1Amine-based compound and organic light-emitting device including the same
Publication Date: 2022.08.03 SAMSUNG DISPLAY CO LTD
  • EP3444241B1 patent drawingFigure 1
  • EP3444241B1 patent drawingFigure 2
  • EP3444241B1 patent drawingFigure 3

AI summary

An amine-based compound represented by Formula 1, in which one of R1 to R10 is a group represented by Formula 2, and an organic light-emitting device including the same are provided: When the amine-based compound is included in an organic light-emitting device as a hole transport material, the device may exhibit excellent I-V-L characteristics, including a low driving voltage, improved efficiency, and improved lifespan.