Organic Light-Emitting Device Spacer Pattern for Electrical Short Prevention
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Solution Overview
Problem
Organic light emitting devices face challenges in achieving uniform light emission and high brightness over large areas due to voltage drops and non-uniform current injection, leading to reduced energy efficiency and stability issues, particularly during encapsulation processes where electrical shorts can occur.
Innovation Solution
The device incorporates a spacer pattern on the first electrode and a metal auxiliary electrode, strategically positioned to prevent electrical shorts and improve current distribution, with the spacer pattern formed using a photosensitive resin composition and specific processing methods to ensure reliability and transparency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a multilayer structure is used to enable low voltage driving, then energy efficiency is improved, but device complexity increases
Solution Approach 1:
The device is divided into multiple functional layers including hole injection layer, hole transport layer, light emitting layer, electron transport layer, and electron injection layer. Each layer performs a specific function to optimize energy efficiency while maintaining manageable complexity through functional segmentation.
Solution Approach 2:
The organic material layer serves multiple functions simultaneously: it acts as the hole transport layer, light emitting layer, and electron transport layer. This multi-functionality reduces the number of separate layers needed, improving energy efficiency without proportionally increasing device complexity.
2Illumination intensity
If the device area is increased to achieve high brightness, then illumination intensity is improved, but voltage drop increases leading to non-uniform current injection
Solution Approach 1:
The patent introduces a conductive layer with specific work function characteristics in strategic positions within the device structure. This conductive layer has different electrical properties than surrounding layers, creating local quality variations that compensate for voltage drops across large areas and ensure uniform current injection throughout the extended device area.
3Ease of manufacture
If encapsulation is performed without cavity using thin film or glass, then device integration is improved, but electrical short between electrodes may occur during the process
Solution Approach 1:
Spacer patterns are formed on the substrate before the encapsulation process. These spacers create preliminary physical separation between the first and second electrodes, preventing direct contact and electrical shorting during encapsulation. This preliminary structural preparation enables safe integration of cavity-less encapsulation.
Solution Approach 2:
The spacer pattern acts as an intermediary element between the first and second electrodes during encapsulation. It provides physical separation and prevents direct electrical contact while allowing the encapsulation process to proceed with thin film or glass without creating short circuits.
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 enhances the uniformity of light emission and prevents electrical shorts during encapsulation, maintaining high brightness and efficiency while ensuring reliable substrate integrity.
Implementation Method 1
the spacer pattern is provided in the non-light emitting area inside of the light emitting area, and the metal auxiliary electrode is provided in the non-light emitting area outside of the light emitting area
Implementation Method 2
a metal auxiliary electrode formed apart from the spacer pattern on the first electrode
Implementation Method 3
when voltage is applied between two electrodes in a structure in which an organic material layer is disposed between an anode and a cathode, holes from the anode and electrons from the cathode are injected into the organic material layer. When the injected holes and electrons meet each other, an exciton is formed, and the exciton falls down again to a bottom state to emit light
Data Source
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AI summary
The present invention relates to an organic light emitting device and a method for preparing an organic light emitting device, and the organic light emitting device comprises a substrate, a first electrode, an organic material layer, and a second electrode in this order, and a spacer pattern on the first electrode.