Organic Light-Emitting Device Electron Blocking Layer

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing organic light-emitting devices face challenges in achieving high efficiency and long lifespan due to electron-hole recombination losses, which are not adequately addressed by current structures and materials.

Innovation Solution

Incorporating an electron blocking layer with a metal halide or metal oxide, excluding organic materials, between the anode and emission layer, with a lowest unoccupied molecular orbital (LUMO) value greater than that of the host in the emission layer, to enhance electron blocking and reduce recombination losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an electron blocking layer with organic material is used, then electron blocking capability is improved, but material denaturation occurs and lifespan is reduced

Engineering Contradiction:

ImprovelifespanVSAvoidmaterial denaturation

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the material composition parameter of the electron blocking layer from organic material to metal halide or metal oxide. This parameter change eliminates material denaturation while maintaining electron blocking capability, thereby extending device lifespan without sacrificing reliability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces durable inorganic materials (metal halide/metal oxide) with organic materials that undergo denaturation. Wait, this is reversed - the patent actually uses the more stable inorganic materials to replace the less stable organic materials, preventing the short-living problem.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Loss of energy

If electron blocking capability is enhanced, then recombination losses are reduced, but device complexity increases

Engineering Contradiction:

Improverecombination lossVSAvoidlayer structure

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent segments the device structure by inserting a distinct electron blocking layer between the anode and emission layer. This segmentation allows independent optimization of electron blocking function without affecting other layers, reducing recombination losses while maintaining manageable device complexity through functional separation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The electron blocking layer acts as an intermediary between the anode and emission layer, specifically controlling electron transport. This intermediary function reduces recombination losses by preventing excess electrons from reaching the emission layer, while the simple metal halide/metal oxide composition keeps the overall device complexity low.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If metal halide or metal oxide is used in electron blocking layer, then electron blocking efficiency is improved, but manufacturing precision requirements increase

Engineering Contradiction:

Improveelectron blocking efficiencyVSAvoidLUMO value control

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent changes the material type parameter to metal halide or metal oxide, which inherently provides higher electron blocking efficiency. The LUMO value control requirement is managed by selecting from a limited set of known metal halide/metal oxide materials with appropriate electronic properties, balancing manufacturing precision with productivity.

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 hole injection and recombination efficiency, leading to higher performance and longer lifespan of the organic light-emitting device by effectively blocking electrons and accumulating carriers, thus reducing material denaturation and enhancing durability.

Implementation Method 1

an actually measured lowest unoccupied molecular orbital (LUMO) value of the electron blocking layer is greater than an actually measured LUMO value of the host in the emission layer

Methodology Applied

Scientific EffectEnergy level alignment (LUMO value difference):

Data Source

PatentUS10236455B2Organic light-emitting device

Publication Date: 2019.03.19 SAMSUNG DISPLAY CO LTD

AI summary

An organic light-emitting device is provided to have high efficiency and long lifespan. The organic light-emitting device includes: a first electrode; a second electrode facing the first electrode; an emission layer disposed between the first electrode and the second electrode and including a host and a dopant; an electron blocking layer disposed between the first electrode and the emission layer; and an electron transport region disposed between the emission layer and the second electrode, in which the electron blocking layer includes a metal halide, a metal oxide, or a combination thereof, and the actually measured lowest unoccupied molecular orbital (LUMO) value of the electron blocking layer is greater than the actually measured LUMO value of the host in the emission layer.