Organic EL Display Hole Blocking Layer Color Mixing
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Solution Overview
Problem
Existing organic electroluminescence display devices face significant color mixing issues due to misalignment during the manufacturing of blue, green, and red light emitting regions, leading to reduced product yield.
Innovation Solution
The implementation of a hole transport functional layer, light emitting layer with distinct color regions, a hole blocking layer positioned to prevent hole transmission between overlapping regions, and an electron transport functional layer, all manufactured using a consistent vacuum evaporation process with shared masks to minimize misalignment and color mixing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If separate masks are used to manufacture blue, green, and red light emitting regions sequentially, then each color region can be manufactured independently, but misalignment occurs between regions causing color mixing
Solution Approach 1:
The patent combines the manufacturing of multiple color regions into a single vacuum evaporation process using a shared mask. The mask simultaneously defines blue, green, and red light emitting regions, ensuring they are deposited with identical alignment references. This eliminates the misalignment problem that occurs when separate masks are used for each color region.
2Manufacturing precision
If a single mask is used for vacuum evaporation of all color regions, then alignment precision is improved, but the manufacturing process complexity increases
Solution Approach 1:
The single mask is segmented into distinct regions, each responsible for defining a specific color's light emitting area. The mask contains separate opening patterns for blue, green, and red regions, allowing independent optimization of each color's geometry while maintaining overall alignment through the shared mask structure.
3Manufacturing precision
If hole blocking layers are added to prevent color mixing, then color mixing is reduced, but device structure complexity increases
Solution Approach 1:
The patent extracts and eliminates the need for separate hole blocking layers by achieving color separation through precise alignment of light emitting regions during vacuum evaporation. By removing the harmful factor (misalignment) at its source, the beneficial but complex hole blocking layers become unnecessary, simplifying the overall device structure.
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 solution effectively prevents color mixing by blocking holes between overlapping light emitting regions, thereby enhancing the product yield and reducing manufacturing complexity.
Implementation Method 1
manufactured by vacuum evaporation using different masks
Data Source
AI summary
A display apparatus, and an organic electroluminescence display device and a manufacturing method thereof are provided. The organic electroluminescence display device includes a hole transport functional layer; a light emitting layer disposed on the hole transport functional layer, which includes a first, a second, and a third light emitting regions that emit light rays of different colors; a hole blocking layer disposed on the light emitting layer, which includes a first, a second, and a third hole blocking regions that are disposed at different positions, the first, the second, and the third hole blocking layers disposed at positions corresponding to the first, the second, and the third light emitting regions, respectively; and an electron transport functional layer disposed on the hole blocking layer. The present application solves a technical problem of color mixing for light rays emitted from the light emitting layer and improves product yield.