OLED Compound with Emitter-Auxiliary Layer for Charge Balance

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Solution Overview

Problem

Organic electroluminescent devices face challenges in maximizing efficiency and lifespan due to charge imbalance at the hole transport layer interface, low T1 values, and metal oxide penetration from the anode, which affect color purity and longevity, necessitating the development of stable and efficient organic material layers.

Innovation Solution

A novel compound with a specific structure is introduced, enhancing luminous efficiency, stability, and lifespan by optimizing energy levels and interfacial properties in organic electronic elements, including a hole transport layer with a high T1 value and high glass transition temperature to delay metal oxide penetration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a hole transport layer material with low HOMO value is used, then charge transport is improved, but T1 value decreases causing exciton transfer to hole transport layer and charge unbalance

Engineering Contradiction:

Improvecharge transportVSAvoidT1 value

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

An emitting-auxiliary layer is introduced as an intermediary between the hole transport layer and the emitting layer. This auxiliary layer has a HOMO level that is higher than the hole transport layer but lower than the emitting layer, and a T1 value higher than both adjacent layers. It acts as a mediator to prevent exciton transfer to the hole transport layer while maintaining charge transport, thereby resolving the contradiction between charge transport efficiency and T1 value stability.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If efficiency is increased by optimizing organic material layer, then driving voltage decreases and lifespan increases, but charge unbalance at interface reduces color purity and efficiency

Engineering Contradiction:

Improveluminous efficiencyVSAvoidcolor purity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The emitting-auxiliary layer serves as a mediator at the interface between the hole transport layer and emitting layer. It prevents charge unbalance and exciton transfer to the hole transport layer, thereby maintaining color purity while allowing high luminous efficiency to be achieved through optimized energy levels and interfacial properties.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention optimizes multiple parameters simultaneously: the HOMO energy levels of adjacent layers, the T1 values of materials, and the energy level differences between layers. By carefully controlling these parameters, the emitting-auxiliary layer prevents charge unbalance while maintaining high efficiency and color purity.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If hole transport layer material has low glass transition temperature, then material stability decreases and metal oxide penetration increases, shortening device lifespan

Engineering Contradiction:

Improvematerial stabilityVSAvoiddevice lifespan

Core Design Contradiction:

Ease of manufactureVSDuration of action of stationary object

Solution Approach 1:

The invention changes the glass transition temperature parameter of the hole transport layer material to a higher value. This parameter change improves material stability, prevents metal oxide penetration from the anode, and extends device lifespan while maintaining the necessary charge transport properties.

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

The novel compound significantly improves luminous efficiency, reduces driving voltage, enhances color purity, and extends the lifespan of organic electronic devices by optimizing energy levels and interfacial properties.

Implementation Method 1

organic light emitting phenomenon refers to a phenomenon that converts electric energy into light energy by using an organic material

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 2

excitons generated in the emitting layer are transferred to the hole transport layer, resulting in charge unbalance

Methodology Applied

Scientific EffectEnergy level transfer:

Implementation Method 3

it is necessary to develop a hole injection layer material that delays the penetration and diffusion of metal oxides from the anode electrode (ITO) into the organic layer

Methodology Applied

Scientific EffectDiffusion barrier: Diffusion Barrier

Implementation Method 4

crystallization of the organic material due to Joule heating generated during driving decreases

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Data Source

PatentUS20230331654A1Compound for organic electric device, organic electric device using same, and electronic device thereof

Publication Date: 2023.10.19 DUK SAN NEOLUX

AI summary

Provided are an OLED compound, an organic electronic element employing the compound, and an electronic device comprising the element, where the compound improves the luminous efficiency, stability and lifetime of the organic electronic element.