Segmented Electrode Organic Light-Emitting Device Current Distribution
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Solution Overview
Problem
Large-area organic light-emitting devices face issues with uneven current distribution leading to current crowding, temperature rises, and potential device damage due to manufacturing processes and material instability, which can result in short circuits or open circuits.
Innovation Solution
The design includes a first and second electrode layer with pad-like patterns separated from each other, connected by conduction members and protection structures that form open or closed circuits between contact portions and continuous patterns, allowing for even current distribution and temperature control to prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the cathode and anode are electrode layers entirely covering the main surface of the device, then the device structure is simple and manufacturing is easier, but local short circuit or open circuit at any signal spot causes damage of the whole device
Solution Approach 1:
The electrode layers are segmented into multiple isolated island patterns instead of continuous layers. Each island pattern corresponds to a specific light-emitting pixel region, electrically isolating different functional areas. This segmentation ensures that local faults in one island do not propagate to other islands, protecting the whole device from complete failure while maintaining manufacturing simplicity through patterned deposition processes.
2Area of stationary object
If the organic light-emitting device is large-area, then it can be applied in light-emitting apparatus for providing planar light source, but uneven current distribution occurs leading to current crowding phenomenon
Solution Approach 1:
The large-area electrode layers are divided into multiple discrete island patterns distributed across the surface. Each island serves as an independent current injection region, enabling localized current control. This segmentation prevents current crowding by distributing current paths uniformly across the large area, as each island independently supplies current to its corresponding pixel region without interfering with adjacent regions.
Solution Approach 2:
Different regions of the device have locally optimized electrode configurations. Each island pattern is specifically positioned and sized to match the underlying pixel structure, ensuring uniform current density within each local region. This local quality approach allows the large-area device to maintain consistent current distribution characteristics across different zones, preventing hot spots and current crowding.
3Device complexity
If electrode layers entirely cover the main surface, then device structure is simpler, but temperature rise in local parts may cause device damage due to current crowding
Solution Approach 1:
The continuous electrode layers are segmented into discrete island patterns, creating physical gaps between adjacent electrode regions. This segmentation reduces localized heat generation by limiting current concentration to specific isolated areas, preventing excessive temperature rise in any single location. The gaps between islands act as thermal isolation zones, allowing heat dissipation without propagating to neighboring regions.
Data Source
AI summary
An organic light-emitting device includes a first substrate, a light-emitting structure layer, a first electrode layer, a second electrode layer, a second substrate, first conduction members, a second conduction member and protection structures. The light-emitting structure layer is disposed on the first substrate. The first electrode layer is disposed on the light-emitting structure layer and includes pad-like patterns. The second electrode layer is disposed between the light-emitting structure layer and the first substrate. The second substrate is adhered on the first electrode layer and includes a first circuit and a second circuit. The first circuit includes a continuous pattern and contact portions. The first conduction members are connected between the first circuit and the first electrode layer. The second conduction member is connected between the second circuit and the second electrode layer. The protection structures respectively form open circuits or close circuits between the contact portions and the continuous pattern.