Stacked Light Emitting Element Layers for High-Resolution OLED Longevity
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Solution Overview
Problem
Existing display panels face challenges in achieving high resolution while enhancing display efficiency and extending service life, particularly in high-resolution display devices that incorporate luminescent materials applied using an open mask.
Innovation Solution
A light emitting element design incorporating a specific layer structure with a hole injection layer, emission layers of different wavelengths, charge generation layers, and a hole transport auxiliary layer containing amine and fluorine-containing compounds, along with precise weight ratios and layer arrangements, to improve display efficiency and longevity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If luminescent materials are applied using an open mask to achieve high resolution, then manufacturing precision is improved, but display efficiency and service life deteriorate
Solution Approach 1:
The patent applies different functional materials to different regions of the device. Specifically, a hole transport auxiliary layer containing amine compounds and fluorine-containing compounds is applied adjacent to the hole injection layer and charge generation layers, while different emission layers (first emission layer for first wavelength, second emission layer for second wavelength) are positioned at different locations. This local differentiation of material properties optimizes both the manufacturing precision for high resolution and the display efficiency/service life by ensuring each region has the appropriate material characteristics for its function.
Solution Approach 2:
The patent employs composite material structures including: (1) The hole transport auxiliary layer combining amine compounds and fluorine-containing compounds in specific weight ratios (3:7 to 5:5); (2) Multiple emission layers with different luminescent materials for different wavelengths; (3) The combination of p-dopant, amine compound, and fluorine-containing compound in the hole injection layer or first p-type charge generation layer. These composite materials provide synergistic effects that simultaneously achieve high resolution patterning and maintain superior display efficiency and service life.
2Reliability
If multiple layers with specific material compositions are added to improve display efficiency, then display efficiency is improved, but device complexity increases
Solution Approach 1:
The hole transport auxiliary layer serves multiple functions simultaneously: it facilitates hole transport, provides structural organization for high-resolution patterning, and contributes to the overall device stability. The emission layers also perform dual functions by emitting light at specific wavelengths while maintaining structural integrity. This multi-functionality reduces the need for additional separate layers, thereby improving display efficiency without proportionally increasing device complexity.
Solution Approach 2:
The device is segmented into functionally distinct layers with clear boundaries: hole injection layer, hole transport auxiliary layer, first emission layer, first n-type charge generation layer, first p-type charge generation layer, second emission layer, and electron transport region. This segmentation allows each layer to be optimized for its specific function while maintaining overall system efficiency. The open mask patterning technique enables precise segmentation in the lateral direction, achieving high resolution without requiring excessive layer complexity.
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
The proposed design enhances display efficiency and extends the service life of display panels by optimizing the layer structure and material composition, resulting in improved performance and reliability.
Implementation Method 1
a hole transport auxiliary layer which is arranged adjacent to at least one of the hole injection layer or the first p-type (kind) charge generation layer
Implementation Method 2
a first emission layer which is arranged on the hole injection layer and emits (e.g., configured to emit) light of a first wavelength, a second emission layer which is arranged on the first p-type (kind) charge generation layer and emits (e.g., configured to emit) light of a second wavelength
Implementation Method 3
each of a water contact angle of each of the first fluorine-containing compound and the second fluorine-containing compound may independently be at least about 110°
Data Source
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AI summary
A light emitting element includes a first electrode, a hole injection layer on the first electrode, a first emission layer which is on the hole injection layer and emits light of a first wavelength, a first n-type charge generation layer on the first emission layer, a first p-type charge generation layer on the first n-type charge generation layer, a second emission layer which is on the first p-type charge generation layer and emits light of a second wavelength different from the first wavelength. An electron transport region is on the second emission layer. A display panel and an electronic device include the same.