Organic EL Device Auxiliary Lines for Aperture Rate
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Solution Overview
Problem
Organic electroluminescent (EL) devices with top-emission structures face an insufficient aperture rate per pixel due to auxiliary lines formed on partitions, leading to increased current demand and reduced device life, especially for finer pixels.
Innovation Solution
The organic EL device features auxiliary lines extending through pixel regions to divide them into subregions, eliminating the need for additional regions on partitions and manufacturing margins, thereby increasing aperture rate and reducing current requirements, achieved through mask deposition and vapor deposition methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If auxiliary lines are formed on the partitions to prevent voltage imbalance, then the conductivity of the common electrode is improved, but the aperture rate per pixel decreases
Solution Approach 1:
The auxiliary lines are moved from the partition regions (horizontal dimension) to the pixel regions (vertical dimension through the common electrode thickness), allowing them to extend through the pixel regions and divide them into subregions. This dimensional relocation enables the auxiliary lines to maintain conductivity function while occupying space that does not reduce the aperture area on the partition level.
Solution Approach 2:
The pixel regions are divided into multiple subregions by the auxiliary lines extending through them. This segmentation allows the auxiliary lines to be integrated within the pixel regions themselves rather than requiring separate partition spaces, thereby increasing the effective aperture rate while maintaining the voltage balance function.
2Manufacturing precision
If partitions are widened to accommodate auxiliary lines and manufacturing margins, then the manufacturing precision is improved, but the aperture area per pixel decreases
Solution Approach 1:
The auxiliary lines are repositioned to extend through the pixel regions in the vertical dimension (through the common electrode), eliminating the need to allocate horizontal space on the partitions for auxiliary line formation. This removes the requirement for additional manufacturing margins on the partitions, allowing the partitions to be narrower and the aperture areas to be larger.
3Illumination intensity
If the aperture rate per pixel is increased, then the light intensity is improved, but the current consumption increases
Solution Approach 1:
The invention uses a transparent conductive material layer with lower resistance (such as IZO or ITO) instead of the conventional high-resistance ITO alone, effectively replacing part of the resistive material with a more conductive alternative. This reduces the voltage gradient and current requirements while maintaining the same light intensity output, thereby extending device life without compromising illumination.
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 aperture rate per pixel, reduces manufacturing costs, and extends the life of the organic EL device by allowing sufficient light intensity with lower current consumption.
Implementation Method 1
auxiliary lines disposed on a top or bottom surface of the second electrode to support the conductivity of the second electrode
Implementation Method 2
light-emitting elements arranged on a substrate, each including a light-emitting layer formed of an organic EL material
Data Source
AI summary
An organic EL device includes a substrate; first electrodes corresponding to individual pixels on the substrate; partitions partitioning the first electrodes to define substantially rectangular pixel regions; organic functional layers, corresponding to the individual pixels, disposed at least in the pixel regions; a second electrode disposed on the organic functional layers and the partitions; and auxiliary lines disposed on a top or bottom surface of the second electrode to support the conductivity of the second electrode. The auxiliary lines extend through the pixel regions so as to cross longer sides thereof and divide the pixel regions into a plurality of subregions.