OLED Cathode Notch Coupling to Reduce IR Drop
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In large-size OLED display devices with a top emission structure, the transparent cathode layer has a high square resistance, leading to increased IR drop, which affects the display's performance.
Innovation Solution
The display substrate includes a compensation electrode, an auxiliary electrode with a first notch, a light-emitting functional layer interrupted at the notch, and a cathode layer coupled to the auxiliary electrode at the notch, allowing indirect coupling to the compensation electrode and reducing resistance and IR drop.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a transparent cathode layer is used in large-size OLED top-emission display devices, then light emission from the cathode side is enabled, but the square resistance of the cathode layer increases, leading to increased IR drop
Solution Approach 1:
An auxiliary electrode is introduced as an intermediary component between the compensation electrode and the cathode layer. This auxiliary electrode provides an additional current conduction path, effectively reducing the IR drop caused by the high square resistance of the transparent cathode layer while maintaining light emission functionality.
Solution Approach 2:
The auxiliary electrode is arranged in a direction substantially perpendicular to the substrate, creating a three-dimensional current conduction path. This vertical arrangement complements the horizontal current flow in the cathode layer, providing an additional dimension for current transport and reducing overall resistance.
2Device complexity
If the cathode layer is directly connected to the compensation electrode, then the structure is simple, but the square resistance is high causing increased IR drop
Solution Approach 1:
The auxiliary electrode serves as a mediator that connects the compensation electrode to the cathode layer through its side surface. This intermediary structure reduces the IR drop by providing an alternative current path while adding minimal complexity to the overall device architecture.
3Ease of manufacture
If the light-emitting functional layer is continuous, then the manufacturing process is simple, but it prevents direct coupling between the cathode layer and auxiliary electrode
Solution Approach 1:
The light-emitting functional layer is segmented or interrupted at the position where it overlaps with the auxiliary electrode. This segmentation creates an opening that allows the cathode layer to be directly coupled to the auxiliary electrode's side surface, enabling effective current conduction while maintaining manufacturing feasibility through standard patterning processes.
Data Source
AI summary
The present disclosure provides a display substrate, a manufacturing method thereof, and a display device. The display substrate includes a substrate, and a compensation electrode, an auxiliary electrode, a light-emitting functional layer, and a cathode layer arranged on one side of the substrate. The auxiliary electrode is arranged on one side of the compensation electrode away from the substrate, and coupled to the compensation electrode. A first notch is formed in a side surface of the auxiliary electrode, and at least a part of the first notch extends in a direction parallel to the substrate. The light-emitting functional layer is arranged on one side of the auxiliary electrode away from the substrate, and interrupted at the first notch. The cathode layer is arranged on one side of the light-emitting functional layer away from the substrate, and coupled to the auxiliary electrode at the first notch.