Organic Semiconductor Electrodes for Cost-Effective OLED Production

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Solution Overview

Problem

The production of electroluminescent organic semiconductor elements, such as OLEDs, faces challenges in achieving high light yield while reducing production costs, particularly due to the high costs and conductivity issues associated with traditional metal or metal oxide electrodes, and the difficulty in manufacturing large-area light sources with transparent electrodes.

Innovation Solution

Replacing traditional electrodes with highly conductive organic layers, which can be partially transparent and composed of materials like PEDOT:PSS, doped polyaniline, or metal oxide charge transfer complexes, and using metallic bus electrodes to improve lateral conductivity and simplify manufacturing processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional metal or metal oxide electrodes (ITO, IZO) are used, then good charge carrier distribution is achieved, but production costs increase and transparency is reduced

Engineering Contradiction:
Improvecharge carrier distributionVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the material parameters by replacing inorganic electrodes with organic conductive materials having different electrical and optical properties. The organic material achieves sufficient conductivity while providing enhanced transparency and reducing production costs through simplified manufacturing processes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention employs cost-effective organic conductive materials that can be applied through simple coating processes, replacing expensive inorganic electrodes. The organic layer can be deposited using low-cost techniques such as spin-coating or printing, significantly reducing manufacturing expenses.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Illumination intensity

If transparent conductive oxides are used for top emitter applications, then transparency is improved, but conductivity becomes problematic and light yield decreases

Engineering Contradiction:
ImprovetransparencyVSAvoidconductivity
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent uses composite organic materials combining conductive polymers or small molecules with dopants to achieve both high transparency and adequate conductivity. The organic composite material provides the dual benefit of optical transparency for top-emitter applications and sufficient electrical conductivity for efficient charge carrier injection.

Inventive Principle:
Principle #40Composite materials

3Manufacturing precision

If lithography processes are used for electrode production, then precise patterning is achieved, but manufacturing complexity and costs increase for large-area devices

Engineering Contradiction:
Improvepatterning precisionVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention extracts the complex lithography step from the manufacturing process by using organic conductive materials that can be directly patterned through simple masking or printing techniques. This eliminates the need for expensive and time-consuming photolithography processes while maintaining adequate patterning precision.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical and chemical complexity of lithography with simpler deposition and patterning methods. Organic conductive layers can be applied by spin-coating, dip-coating, or printing, followed by simple thermal or photonic curing, substituting the complex multi-step lithography process with more straightforward techniques.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 approach reduces production costs, enhances light yield by improving charge carrier distribution, and allows for easier repair of defects in organic light-emitting diodes without significantly impacting overall performance, enabling cost-effective and efficient production of organic light-emitting diodes with improved transparency and conductivity.

Implementation Method 1

a layer generating light by charge carrier recombination

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP2118944B1Electroluminescent organic semiconductor element
Publication Date: 2018.06.13 OSRAM OLED
  • EP2118944B1 patent drawingFigure 1~3
  • EP2118944B1 patent drawingFigure 4~6
  • EP2118944B1 patent drawingFigure 7~8

AI summary

The invention relates to an electroluminescent organic semi-conductor element comprising a first electrode (2) that is arranged on a substrate (6). Said semiconductor element also contains a second electrode (3) and at least one organic layer (1) that is arranged between the first electrode and the second electrode (2, 3). Said organic layer comprises a layer that generates light by recombining charge carriers. At least one electrode of the first and the second electrodes contains a highly conductive organic partial layer (21, 31).