Blue Luminescent Compound Structure for Narrow OLED Emission

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Solution Overview

Problem

Existing fluorescent blue luminescent materials suffer from low luminescence efficiency and color purity, which is a challenge in achieving high-performance organic light-emitting devices.

Innovation Solution

A blue luminescent compound with a nitrogen-containing aromatic heterocyclic skeleton and bulky substituents is developed, which suppresses intermolecular aggregation, resulting in a narrow emission spectrum and improved luminescence efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If fluorescent materials are used for blue luminescence, then device lifespan is improved, but luminescence efficiency deteriorates (only about 5% efficiency)

Engineering Contradiction:
Improvedevice lifespanVSAvoidluminescence efficiency
Core Design Contradiction:
Duration of action of stationary objectVSUse of energy by moving object

Solution Approach 1:

The patent introduces a specific molecular structure with a nitrogen-containing aromatic heterocyclic skeleton and bulky substituents that change the photophysical parameters of the material. This structural modification enables the material to achieve both long lifespan and high luminescence efficiency by optimizing the balance between singlet and triplet state utilization while maintaining structural stability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite luminescent system by combining the nitrogen-containing heterocyclic core structure with specific aromatic substituents (such as carbazole, triphenylamine groups). This composite molecular design allows the material to exhibit both the stability needed for long lifespan and the efficient energy utilization required for high luminescence efficiency.

Inventive Principle:
Principle #40Composite materials

2Reliability

If conventional blue luminescent materials are used, then device operation is maintained, but color purity deteriorates (wide emission spectrum)

Engineering Contradiction:
Improvedevice operationVSAvoidcolor purity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by introducing bulky substituents at specific positions on the nitrogen-containing heterocyclic skeleton. These localized structural modifications create steric hindrance that prevents intermolecular aggregation, thereby narrowing the emission spectrum and improving color purity while maintaining overall device operation reliability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The molecular design achieves equipotentiality by creating a balanced electronic structure where the nitrogen-containing heterocyclic core and aromatic substituents are electronically coupled in a way that distributes electron density uniformly. This balanced electronic distribution reduces non-radiative decay pathways and narrows the emission spectrum, improving color purity without compromising device operation.

Inventive Principle:
Principle #12Equipotentiality

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 achieves high color purity and luminescence efficiency by maintaining a small full width at half maximum (FWHM) and peak wavelength within the blue wavelength region, enhancing the performance of organic light-emitting devices.

Implementation Method 1

fluorescent materials have been used for blue luminescent materials in view of device lifespan, and increasing device efficiency has become an issue

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 2

A blue luminescent compound with a nitrogen-containing aromatic heterocyclic skeleton and bulky substituents is developed, which suppresses intermolecular aggregation

Methodology Applied
Scientific EffectSteric hindrance:

Data Source

PatentEP4450589B1Blue luminescent compound and organic light-emitting device
Publication Date: 2025.11.19 SAMSUNG DISPLAY CO LTD
  • EP4450589B1 patent drawingFigure 1(a)~1(c)
  • EP4450589B1 patent drawingFigure 2
  • EP4450589B1 patent drawingFigure 3

AI summary

A blue luminescent compound including a nitrogen-containing aromatic heterocyclic skeleton and at least two aromatic substituents bonded to the nitrogen-containing aromatic heterocyclic skeleton, wherein the nitrogen-containing aromatic heterocyclic skeleton includes, as substituents, four branched or cyclic alkyl groups each having 3 to 20 carbon atoms, and the nitrogen-containing aromatic heterocyclic skeleton and the at least two aromatic substituents are not located on the same plane.