Blue Phosphorescent Organic EL Host Material for Wet Coating

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current organic electroluminescence elements using blue phosphorescence face challenges in achieving high luminous efficiency, low driving voltage, and long lifetime, particularly in terms of solubility, solution stability, and driving voltage of host and electron transport materials, which are essential for large-scale, low-cost production and high productivity.

Innovation Solution

An organic electroluminescence element comprising a light-emitting layer with a compound represented by a specific formula, featuring a carbazolyl or azacarbazolyl group, which improves solubility and carrier transport properties, allowing for a low driving voltage and high luminous efficiency, and is suitable for a wet coating process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional host materials and electron transport materials are used in blue phosphorescence organic EL elements, then the element can operate, but the solubility and solution stability are insufficient, preventing wet coating process implementation

Engineering Contradiction:
Improvewet coating process applicabilityVSAvoidsolution stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent modifies the molecular structure of host materials and electron transport materials by introducing specific functional groups and molecular weight adjustments to improve solubility parameters while maintaining solution stability, enabling wet coating process implementation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent develops composite material systems combining specially designed host materials with electron transport materials that have complementary properties, achieving both high solubility for wet processing and sufficient solution stability for device fabrication

Inventive Principle:
Principle #40Composite materials

2Use of energy by moving object

If blue phosphorescence luminescent materials with high T1 are used, then the luminous efficiency can be improved, but the driving voltage becomes too high and lifetime is reduced

Engineering Contradiction:
Improveluminous efficiencyVSAvoiddriving voltage
Core Design Contradiction:
Use of energy by moving objectVSPower

Solution Approach 1:

The patent optimizes the local electronic structure and energy level distribution in different regions of the device, particularly at interfaces between layers, to facilitate efficient charge injection and transport while maintaining high luminous efficiency from blue phosphorescence materials

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent introduces intermediary layers and specially designed host materials that act as mediators between the blue phosphorescence luminescent materials and electrodes, facilitating charge transport and reducing driving voltage while preserving high luminous efficiency

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If precise control of luminescence center is implemented, then the emission stability can be improved, but the manufacturing complexity increases

Engineering Contradiction:
Improveemission stabilityVSAvoidlayer structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple functions into integrated material systems where host materials simultaneously provide luminescence center stabilization, charge transport, and structural organization, reducing the number of separate layers needed while maintaining emission stability

Inventive Principle:
Principle #5Merging (Combining)

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 solution enables an organic electroluminescence element with high emission efficiency, low driving voltage, and extended lifetime, facilitating large-scale production and improved light-emitting properties.

Implementation Method 1

a light-emitting layer containing a phosphorescence emitting compound (3) wherein at least one of the organic compound layers contains a compound represented by Formula (1)... an exciton is generated by an electron and a hole being injected into the emitting layer to be recombined, resulting emission utilizing light release (fluorescence and phosphorescence) at the time of deactivation of said exciton

Methodology Applied
Scientific EffectPhosphorescence: Phosphorescence

Data Source

PatentEP2453496B1Organic electroluminescent element, novel compound, lighting device and display device
Publication Date: 2018.11.14 KONICA MINOLTA INC
  • EP2453496B1 patent drawingFigure 1~3
  • EP2453496B1 patent drawingFigure 4~5
  • EP2453496B1 patent drawingFigure 6~7e

AI summary

Provided are an organic electroluminescent element having high luminous efficiency, low driving voltage, and long life; novel compound; lighting device; and display device.