OLED Pixel Defining Layer Thickness and Brightness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing OLED display technologies face challenges in achieving a reduced thickness and uniform brightness due to non-uniform thickness of organic light-emitting layers and the use of thick pixel defining layers, which affect the overall performance and efficiency of the display.
Innovation Solution
The use of a metal-fluoride ionic compound-based pixel defining layer with a thickness of about 10 nanometers to 100 nanometers, which covers the boundary surface of the organic light-emitting layers and exposes a substantially flat area, allowing for a uniform thickness and brightness across the pixel areas, and the arrangement of color filters in specific patterns to enhance light emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a thick pixel defining layer is used to cover the boundary surface of organic light-emitting layers, then the pixel areas are well-defined and manufacturing is easier, but the overall thickness of the OLED display increases and brightness uniformity deteriorates
Solution Approach 1:
The patent changes the material parameter of the pixel defining layer from conventional organic materials to metal-fluoride ionic compounds, which enable the layer to achieve the required pixel definition function at a much reduced thickness of 10-100 nanometers, thereby resolving the contradiction between ease of manufacture and overall thickness
Solution Approach 2:
The patent uses composite material structure where the pixel defining layer is formed of metal-fluoride ionic compounds combined with organic light-emitting layers, creating a multi-functional layer system that achieves both precise pixel definition and thin profile simultaneously
2Ease of manufacture
If the organic light-emitting layers are formed with greater area than pixel areas, then manufacturing is simplified, but the brightness uniformity across pixel areas deteriorates due to non-uniform thickness
Solution Approach 1:
The patent applies local quality by making the pixel defining layer selectively cover only the boundary surfaces of organic light-emitting layers in the non-pixel areas, while leaving the pixel areas exposed with uniform thickness, thereby achieving both manufacturing simplicity and brightness uniformity through localized functional differentiation
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 results in a reduced overall thickness of the OLED display device while maintaining substantially uniform brightness across the pixel areas, improving the display's performance and efficiency.
Implementation Method 1
The pixel defining layer includes a metal-fluoride ionic compound and the metal-fluoride ionic compound includes one of LiF, BaF2, and CsF. The pixel defining layer has a thickness of about 10 nanometers to about 100 nanometers.
Implementation Method 2
Holes and electrons are injected into the organic light-emitting layer through the anode and cathode electrodes and are recombined in the organic light-emitting layer to generate excitons. The excitons emit energy as light, which is discharged when an exciton returns to a ground state.
Data Source
AI summary
An organic light-emitting diode (OLED) display is disclosed. In one aspect, the OLED display includes a substrate having a plurality of pixel areas, which serves as a light-emitting area, and a non-pixel area, which serves as a non-light-emitting area. The OLED display also includes a plurality of first electrodes formed over the substrate in areas respectively corresponding to the pixel areas and a plurality of organic light-emitting layers formed over the first electrodes. The OLED display further includes a pixel defining layer formed in the non-pixel area of the substrate to cover a boundary surface of the organic light-emitting layers and to define the pixel areas, and a second electrode formed over the organic light-emitting layers and the pixel defining layer.