Versatile Hole Transporting Matrix for Polychromatic OLEDs

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Solution Overview

Problem

Current OLEDs face inefficiencies in charge carrier balance and quantum efficiency, particularly in polychromatic devices where multiple materials complicate manufacturing and reduce performance, with a need for versatile materials that can be used across various emitters without deteriorating performance parameters.

Innovation Solution

A high-versatility hole transporting matrix compound, represented by formula (1), is developed for use in both phosphorescent and fluorescent OLEDs, capable of functioning as both a hole transporting and electron blocking layer, enhancing operational efficiency and longevity across different emission colors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If multiple different materials are used in polychromatic OLEDs to achieve desired chromaticity, then the color performance is improved, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:
ImprovechromaticityVSAvoidnumber of materials
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent applies universality by developing a single hole transporting matrix compound (formula 1) that can be used across multiple OLED types (phosphorescent and fluorescent) and in multiple layers (hole transporting layer and electron blocking layer), eliminating the need for different materials in polychromatic devices while maintaining optimal performance across various emitters

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

Solution Approach 2:

The patent merges the functions of hole transporting layers and electron blocking layers by using the same matrix compound (formula 1) in both layers, thereby simplifying the material system while achieving both charge transport and electron blocking functions necessary for optimal OLED performance

Inventive Principle:
Principle #5Merging (Combining)

2Illumination intensity

If multiple different materials are used in polychromatic OLEDs, then the desired chromaticity is achieved, but the manufacturing throughput and cost efficiency decrease

Engineering Contradiction:
ImprovechromaticityVSAvoidmanufacturing throughput
Core Design Contradiction:
Illumination intensityVSProductivity

Solution Approach 1:

The universal matrix compound (formula 1) enables simplified manufacturing processes by allowing the same material to be used across different OLED types and layers, reducing the complexity of material handling, storage, and processing while maintaining high manufacturing throughput and color performance

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

3Reliability

If specialized materials are used for each OLED type (phosphorescent vs fluorescent), then the performance is optimized, but the material versatility and ease of manufacture decrease

Engineering Contradiction:
Improveperformance optimizationVSAvoidmaterial versatility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The matrix compound of formula (1) achieves universality by being applicable to both phosphorescent and fluorescent OLEDs, as well as serving dual purposes as both hole transporting and electron blocking materials, thereby maintaining performance optimization while significantly enhancing material versatility

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

Solution Approach 2:

The patent utilizes parameter changes by adjusting the dopant ratio (92:8 weight ratio with dopant) and molecular structure parameters of the matrix compound to achieve optimal performance across different OLED types and layer functions, demonstrating adaptability through controlled parameter variation

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 compound (1) achieves comparable performance to state-of-the-art matrices in phosphorescent OLEDs and outperforms them in fluorescent OLEDs, offering improved operational voltage and efficiency while maintaining device longevity, thus enabling high-performance monochromatic and polychromatic devices with simplified manufacturing processes.

Implementation Method 1

hole transporting and/or electron blocking layers... responsible for transport of negative and positive charge carriers into the emission layer

Methodology Applied
Scientific EffectCharge carrier transport: Conduction (electrical)

Implementation Method 2

hole transporting and/or electron blocking layers... responsible for transport of negative and positive charge carriers

Methodology Applied
Scientific EffectCharge carrier blocking: Electrical Resistance

Implementation Method 3

the electroluminescence (EL) property of certain organic materials is used... Recombination of these charge carriers results in an excited state, which relaxes to the ground state under light emission

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP2924753B1Polychromatic light emitting devices and versatile hole transporting matrix for them
Publication Date: 2017.04.19 NOVALED GMBH
  • EP2924753B1 patent drawingFigure 1~2b
  • EP2924753B1 patent drawingFigure 3
  • EP2924753B1 patent drawing

AI summary

The present invention relates to organic light-emitting diodes (OLEDs) comprising at least one substantially organic layer comprising 1,N,N,N',N'-pentakis(1,1'-biphenyl-4-yl)-phenylene-3,5-diamine matrix compound and to new 1,N,N,N',N'-pentakis(1,1'-biphenyl-4-yl)-phenylene-3,5-diamine compound useful especially as hole-transporting and/or electron-blocking layer matrix in OLEDs.