OLED Bottom Electrode Ion Beam Cleaning for Lower Injection Voltage

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Solution Overview

Problem

The manufacturing process of organic light emitting devices often results in impurities such as polymer residues and oxidation films on the surface of the bottom electrode, which inhibit electron and hole injection, leading to performance deterioration and increased operation voltage.

Innovation Solution

The surface treatment of the bottom electrode using ion beam etching effectively removes these impurities, ensuring smooth electron and hole injection and maintaining a flat electrode surface, thereby improving the device's performance and reducing operation voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the bottom electrode is formed by conventional manufacturing processes, then the device structure is simple and manufacturing is easy, but impurities such as polymer residues and oxidation films remain on the electrode surface, inhibiting electron and hole injection

Engineering Contradiction:

Improveelectron and hole injection performanceVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies ion beam etching as a preliminary surface treatment step to the bottom electrode before depositing the organic emission layer. This preliminary action removes impurities such as polymer residues and oxidation films from the electrode surface, ensuring clean interfaces that facilitate efficient electron and hole injection without compromising the overall manufacturing feasibility

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces conventional mechanical or chemical cleaning methods with ion beam etching, which uses accelerated ions to physically sputter and remove impurities from the electrode surface. This substitution provides more effective impurity removal while maintaining process control and avoiding contamination associated with traditional cleaning approaches

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If ion beam etching is applied to surface-treat the bottom electrode, then impurity removal is effective and injection performance is improved, but the manufacturing process becomes more complex

Engineering Contradiction:

Improveinjection performanceVSAvoidprocess steps

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent optimizes the ion beam etching parameters including ion energy, ion flux, and treatment duration to achieve effective impurity removal while minimizing the addition of process complexity. By carefully controlling these parameters, the treatment can be integrated into existing manufacturing workflows with minimal disruption to the overall process architecture

Inventive Principle:

Principle #35Parameter changes

3Productivity

If impurities remain on the bottom electrode surface, then the manufacturing process is simpler, but the operation voltage increases and device performance deteriorates

Engineering Contradiction:

Improvedevice efficiencyVSAvoidoperation voltage

Core Design Contradiction:

ProductivityVSUse of energy by stationary object

Solution Approach 1:

The patent specifically targets and extracts impurities such as polymer residues and oxidation films from the bottom electrode surface through ion beam etching. By removing these harmful substances that create barriers to charge injection, the device achieves lower operation voltages and improved efficiency without requiring additional energy-consuming operations during device operation

Inventive Principle:

Principle #2Taking out (Extraction)

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

Ion beam etching ensures that electron and hole injection progress smoothly, lowers the operation voltage, and enhances the reliability and performance of the organic light emitting device by maintaining a flat electrode surface, thus improving the overall efficiency and longevity of the device.

Implementation Method 1

The surface treatment of the bottom electrode using ion beam etching effectively removes these impurities

Methodology Applied

Scientific EffectIon beam etching: Ion Beam

Implementation Method 2

ion beam etching effectively removes these impurities

Methodology Applied

Scientific EffectSputtering: Sputtering

Data Source

PatentUS8058796B2Organic light emitting device having surface-treated bottom electrode

Publication Date: 2011.11.15 LG DISPLAY CO LTD

AI summary

Disclosed is a method of manufacturing an organic light emitting device, which comprises the steps of successively stacking a bottom electrode, an organic layer including an emission layer, and a top electrode, the method further comprising the step of: surface-treating the bottom electrode with ion beam etching before stacking the organic layer. By effectively removing impurities such as polymer materials or oxidation films, which are formed on the bottom electrode of the organic light emitting device, not only electron injection and hole injection in the organic light emitting device progress smoothly, but also an operation voltage is lowered and performance reliability can ensured because the surface roughness of the bottom electrode is maintained at the same level before and after ion milling.