OLED Conductive Connector Segmentation for Leakage Current Control
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Solution Overview
Problem
Organic light emitting devices (OLEDs) are prone to short-circuit defects due to factors like pinholes, cracks, and coating roughness, leading to decreased light output or complete failure, and existing solutions either increase the organic layer thickness unnecessarily or fail to completely prevent defects.
Innovation Solution
An OLED design featuring a first electrode with conductive units connected in parallel through a conductive connector and a short-circuit preventing layer, where the conductive connector has a length-to-width ratio of 10:1 or more, providing resistance to prevent excessive leakage current and maintain operation even with short-circuit defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the interval between anode and cathode is increased to decrease short-circuit defects, then reliability is improved, but the organic layer thickness must be unnecessarily increased, adding manufacturing cost and device complexity
Solution Approach 1:
The first electrode is segmented into multiple conductive units (202, 204, 206, 208) that are electrically connected in parallel through conductive connectors. This segmentation allows the electrode to maintain electrical functionality even when short-circuit defects occur in certain regions, as current can flow through alternative parallel paths. The segmentation principle resolves the contradiction by enabling reliability improvement without increasing the overall device thickness.
Solution Approach 2:
A short-circuit preventing layer is introduced as an intermediary component between the conductive units and the second electrode. This layer acts as a mediator that blocks direct short-circuit paths while maintaining the necessary electrical connections. The intermediary layer prevents harmful direct contact between electrodes without requiring increased spacing, thus resolving the contradiction between reliability and device complexity.
2Reliability
If conductive units are connected in parallel through conductive connectors with high resistance, then leakage current is limited and reliability is improved, but operating voltage increases
Solution Approach 1:
The conductive connectors are designed with specific local properties - they have controlled resistance values that are higher than the organic layer resistance but optimized to balance leakage current prevention and voltage drop. The local quality of the connectors (their resistance, dimensions, and material composition) is specifically tailored to achieve the desired trade-off between reliability and operating voltage.
Solution Approach 2:
The resistance parameter of the conductive connectors is carefully controlled and optimized. By adjusting the resistance parameter within a specific range (higher than organic layer resistance but not excessively high), the design achieves effective leakage current limitation while maintaining acceptable operating voltage levels. This parameter optimization resolves the contradiction between reliability improvement and voltage increase.
3Reliability
If the organic layer thickness is increased to prevent short-circuit defects, then reliability is improved, but manufacturing cost increases and the method does not completely remove defects
Solution Approach 1:
The electrode structure is segmented into multiple conductive units with parallel connections, allowing the device to tolerate short-circuit defects in the organic layer without complete failure. This segmentation approach improves reliability without requiring increased organic layer thickness, thereby avoiding the associated manufacturing cost increases.
Solution Approach 2:
The short-circuit preventing layer serves as an intermediary that provides enhanced defect prevention at the interface between electrodes. This intermediary structure achieves superior reliability compared to simply thickening the organic layer, while maintaining cost-effectiveness by using targeted prevention rather than blanket thickness increase.
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 design allows the OLED to maintain normal operation and prevent excessive leakage current, even with increased short-circuit occurrence areas, thereby minimizing light output loss and ensuring stable operation without increasing the organic layer thickness unnecessarily.
Implementation Method 1
the conductive connector has a length-to-width ratio of 10:1 or more, providing resistance to prevent excessive leakage current
Implementation Method 2
Exciton is generated when the injected hole and electron encounter, and light is generated when the exciton falls down to a bottom state
Data Source
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Figure 2~3
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AI summary
The present specification provides an organic light emitting device (OLED) and a method for manufacturing the OLED.