Deuterated Organic EL Emitter Layers for Lifetime Extension

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Solution Overview

Problem

Organic electroluminescence devices face challenges in achieving long lifetimes due to degradation issues in their emitting layers, particularly when exposed to interfaces with hole-transporting and electron-transporting layers.

Innovation Solution

Incorporating a compound with at least one deuterium atom in the emitting region, specifically in one of the emitting layers, to enhance the device's longevity by reducing degradation and improving performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional emitting layers are used in organic EL devices, then the device structure is simple and manufacturing is easier, but the device lifetime is short due to degradation at interfaces with transporting layers

Engineering Contradiction:

Improvedevice lifetimeVSAvoidemitting layer structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The emitting region is divided into multiple emitting layers (first emitting layer and second emitting layer) with different functionalities. One layer is optimized for hole injection/transport while the other is optimized for electron injection/transport, allowing each layer to specialize in reducing degradation at its respective interfaces with transporting layers.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different emitting layers are assigned different materials and properties tailored to their specific locations and functions. The first emitting layer uses materials optimized for hole-transporting layer interfaces, while the second emitting layer uses materials optimized for electron-transporting layer interfaces, thereby locally addressing degradation issues at each interface.

Inventive Principle:

Principle #3Local quality

2Reliability

If deuterated compounds are incorporated in the emitting layers, then device lifetime and stability are improved, but the manufacturing process becomes more complex

Engineering Contradiction:

Improvedevice lifetimeVSAvoidmanufacturing process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Deuterated compounds are used to replace conventional compounds in the emitting layers. The deuterium substitution changes the chemical and physical parameters of the materials, providing enhanced stability and lifetime while maintaining the same device structure and manufacturing approach.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20230047477A1Organic electroluminescence device and electronic apparatus

Publication Date: 2023.02.16 IDEMITSU KOSAN CO LTD

AI summary

An organic electroluminescence device comprising: an anode, a cathode, and an emitting region between the anode and the cathode, wherein the emitting region comprises a first emitting layer and a second emitting layer, the first emitting layer and the second emitting layer are directly adjacent to each other, the first emitting layer is between the anode and the second emitting layer, and one of the first emitting layer and the second emitting layer comprises a compound having at least one deuterium atom.