OLED Display Intermediate Layer Electron Trapping
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Solution Overview
Problem
Current organic light emitting diode (OLED) displays face challenges in maintaining image quality due to color mixture from remaining electrons, which reduces the lifespan and image quality, particularly when the first and second organic emission layers are closer to the second electrode than the third organic emission layer.
Innovation Solution
Incorporating an intermediate layer between the first and second organic emission layers and between the second and third organic emission layers to trap remaining electrons, and using a manufacturing method that deposits a common layer and patterned organic layers using only three Fine Metal Masks (FMMs) to optimize the optical thickness and reduce thermal damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the first and second organic emission layers are positioned closer to the second electrode than the third organic emission layer, then the manufacturing process is simplified, but color mixture occurs due to remaining electrons which reduces image quality and lifespan
Solution Approach 1:
An intermediate layer is introduced between the third organic emission layer and the first/second organic emission layers. This intermediate layer acts as a mediator that prevents remaining electrons from causing color mixture, thereby resolving the contradiction between simplified layer arrangement and image quality maintenance.
2Manufacturing precision
If multiple Fine Metal Masks (FMMs) are used for depositing patterned organic layers, then manufacturing precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines the deposition of multiple organic emission layers into a single FMM process step. By designing the organic emission layer structure and deposition conditions appropriately, multiple layers are formed simultaneously through one mask, reducing the number of FMMs from three to one while maintaining manufacturing precision.
3Productivity
If laser transfer process uses higher energy to improve transfer efficiency, then productivity is improved, but thermal damage increases affecting material quality
Solution Approach 1:
The laser transfer process uses periodic pulsed laser irradiation instead of continuous high-energy exposure. This allows controlled energy delivery that achieves efficient transfer while preventing excessive thermal accumulation and damage to the organic materials.
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 approach enhances the lifespan and image quality of OLED displays by preventing electron flow and color mixture, while reducing manufacturing costs and improving resolution by using fewer FMMs and minimizing thermal damage during the laser transfer process.
Implementation Method 1
Incorporating an intermediate layer between the first and second organic emission layers and between the second and third organic emission layers to trap remaining electrons
Implementation Method 2
transferred the patterned organic layer on the first common layer by using a laser
Data Source
AI summary
An OLED display and associated methods, including a substrate; a first electrode; a second electrode; and an organic emission layer between the first and second electrodes, the organic emission layer including first-third organic emission layers, wherein the third organic emission layer is commonly disposed on the first electrode in the first-third subpixels, the first organic emission layer is in the first subpixel, the second organic emission layer is on the third organic emission layer in the first to third subpixels, an intermediate layer is between the first organic emission layer and the third organic emission layer in the first subpixel and between the second organic emission layer and the third organic emission layer in the second subpixel, and a HTL is between the first organic emission layer and the intermediate layer in the first subpixel and between the second organic emission layer and the intermediate layer in the second subpixel.