Pyrene Derivative Blue Light Emission Lifetime

Solution Overview

Problem

Conventional organic electroluminescence (EL) devices using pyrene derivatives suffer from insufficient half-life and poor color purity, limiting their luminance and efficiency, especially for blue light emission.

Innovation Solution

The use of a pyrene derivative with a specific structure, represented by general formula (1) or (2), as a light-emitting material in an organic EL device, which includes a substituted or unsubstituted pyrene residue linked by aromatic hydrocarbon or heterocyclic groups, enhances luminous efficiency and extends the device's lifetime.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If conventional pyrene derivatives are used as light emitting materials, then the device structure is simple and manufacturing is easy, but the half-life is insufficient and color purity is poor

Engineering Contradiction:

Improvehalf-lifeVSAvoidmolecular structure complexity

Core Design Contradiction:

Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The patent uses composite pyrene derivative molecules combining pyrene residues with specific linker groups (fluorene, indene, indolizine, dihydroindolizine) to create a composite material that achieves both long half-life (over 1000 hours) and high color purity (CIE 1931 coordinates within specified ranges), resolving the contradiction between durability and structural complexity

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent introduces specific local structural features (kinked configurations, ortho-substitution patterns, specific linker groups) at critical positions of the pyrene derivative molecules to optimize both stability and optical properties, achieving localized improvement in half-life and color purity without excessive overall complexity

Inventive Principle:

Principle #3Local quality

2Use of energy by moving object

If conventional pyrene derivatives are used, then the device can be manufactured at lower cost, but luminous efficiency and luminance are insufficient

Engineering Contradiction:

Improveluminous efficiencyVSAvoidmanufacturing cost

Core Design Contradiction:

Use of energy by moving objectVSEase of manufacture

Solution Approach 1:

The patent optimizes molecular parameters of pyrene derivatives including HOMO/LUMO energy levels, molecular weight, and structural configuration to achieve high luminous efficiency (above 5 cd/A) and long wavelength blue emission (460-480 nm), balancing performance improvement with manufacturing feasibility

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent develops pyrene derivatives that can be synthesized through cost-effective routes using readily available starting materials and standard organic synthesis techniques, maintaining ease of manufacture while achieving extended operational lifetime (over 1000 hours) that replaces frequently更换 materials

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Manufacturing precision

If conventional pyrene derivatives are used, then the device structure is simpler, but color purity is poor especially for blue light emission

Engineering Contradiction:

Improvecolor purityVSAvoidmolecular structure complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent introduces specific local structural features (kinked configurations, ortho-substitution patterns, specific linker groups) at critical positions of the pyrene derivative molecules to optimize both stability and optical properties, achieving localized improvement in half-life and color purity without excessive overall complexity

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite pyrene derivative molecules combining pyrene residues with specific linker groups (fluorene, indene, indolizine, dihydroindolizine) to create a composite material that achieves both long half-life (over 1000 hours) and high color purity (CIE 1931 coordinates within specified ranges), resolving the contradiction between durability and structural complexity

Inventive Principle:

Principle #40Composite materials

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 pyrene derivative-based organic EL device achieves high luminous efficiency and long lifetime with improved color purity, specifically for blue light emission, while being cost-effective to produce.

Implementation Method 1

An organic electroluminescence device (hereinafter, which may sometimes be abbreviated as EL) is a spontaneous light emitting device which utilizes the principle that a fluorescent substance emits light by energy of recombination of holes injected from an anode and electrons injected from a cathode when an electric field is applied

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS7585574B2Pyrene derivative and organic electroluminescence device making use of the same

Publication Date: 2009.09.08 IDEMITSU KOSAN CO LTD

AI summary

Provided are a pyrene derivative of a specified structure and an organic electroluminescence device including an organic thin film layer formed of one or multiple layers including at least a light emitting layer, the organic thin film layer being interposed between a cathode and an anode, in which at least one layer of the organic thin film layer contains the pyrene derivative alone or as a component of mixture. Thus, there are provided an organic electroluminescence device capable of obtaining long-life blue light emission with high luminous efficiency and a novel pyrene derivative for realization thereof.