Organic EL Device Emission Layers for Lifetime

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Solution Overview

Problem

Current organic electroluminescence devices face limitations in performance and lifetime, particularly in terms of luminance, emission wavelength, efficiency, drive voltage, and longevity, which are not adequately addressed by existing compounds used in these devices.

Innovation Solution

The use of a specific organic electroluminescence device configuration featuring a first emitting layer with a host material containing a compound represented by formula (1) and a second emitting layer with a host material containing a compound represented by formula (2), where the layers are in direct contact, enhancing the device's performance and longevity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional compounds are used in organic EL devices, then device structure is simple, but performance (luminance, efficiency, lifetime) is insufficient

Engineering Contradiction:

Improvedevice lifetimeVSAvoidemitting layer structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The emitting layer is divided into multiple distinct layers (first emitting layer with compound (1), second emitting layer with compound (2)), where each layer contains specific compounds with defined molecular structures. This segmentation allows optimization of different functional requirements in separate layers, improving overall device lifetime and performance without compromising structural simplicity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs composite material design by combining specific organic compounds with defined molecular structures (formulas (1) and (2)) in different emitting layers. These composite materials, featuring specific molecular architectures with substituents and core structures, enable enhanced device performance and lifetime while maintaining manageable device complexity.

Inventive Principle:

Principle #40Composite materials

2Illumination intensity

If conventional emitting layers are used, then manufacturing process is simple, but luminance and emission efficiency are limited

Engineering Contradiction:

ImproveluminanceVSAvoidlayer configuration

Core Design Contradiction:

Illumination intensityVSEase of manufacture

Solution Approach 1:

Different emitting layers are designed with specific local qualities through the use of compounds (1) and (2) with distinct molecular structures and substituents. Each layer is optimized for specific functions (e.g., hole injection, electron injection, recombination), enabling high luminance and emission efficiency while maintaining ease of manufacture through targeted material selection rather than complex processing.

Inventive Principle:

Principle #3Local quality

3Power

If standard organic EL structure is used, then device complexity is low, but drive voltage and performance are insufficient

Engineering Contradiction:

Improvedrive voltageVSAvoidemitting layer composition

Core Design Contradiction:

PowerVSDevice complexity

Solution Approach 1:

The patent optimizes drive voltage and performance by changing molecular parameters of the compounds used in emitting layers. Specific molecular structures (formulas (1) and (2)) with varying substituents and core structures enable tuning of electrical and optical properties, achieving appropriate drive voltage levels while maintaining manageable device complexity through systematic material design.

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

This configuration improves the performance and extends the lifetime of the organic electroluminescence device by optimizing the interaction between the emitting layers, leading to enhanced luminance, emission characteristics, and efficiency.

Implementation Method 1

An organic electroluminescence device has found its application in a full-color display for mobile phones, televisions and the like. When a voltage is applied to an organic EL device, holes and electrons are injected from an anode and a cathode, respectively, into an emitting layer. The injected holes and electrons are recombined in the emitting layer to form excitons.

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS20230089512A1Organic electroluminescent element and electronic device

Publication Date: 2023.03.23 IDEMITSU KOSAN CO LTD

AI summary

An organic electroluminescence device includes: an anode; a cathode; a first emitting layer; and a second emitting layer provided between the first emitting layer and the cathode, in which the first emitting layer contains, as a first host material, a first compound that has at least one group represented by a formula (11) below and that is represented by a formula (1) below, the second emitting layer contains, as a second host material, a second compound represented by a formula (2) below, the second compound has at least one deuterium atom, and the first emitting layer and the second emitting layer are in direct contact with each other.