OLED Reflecting Electrode Luminance Enhancement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Organic light emitting diode displays face challenges in achieving high luminance without complicating the driving scheme, particularly when used outdoors where brightness is required to surpass sunlight, and there are limitations with current pentile structures that increase luminance but decrease resolution and complicate driving.
Innovation Solution
The design includes a substrate with a transistor, a reflecting electrode, a color filter, a first electrode made of transparent conductive material, a pixel definition layer exposing the first electrode, a white emission layer, and a second electrode, where the first and second electrodes are made of transparent conductive materials like ITO or IZO, and the reflecting electrode is made of silver, allowing for high luminance without complex driving schemes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If current flowing in the organic light emitting diode is increased to achieve high luminance, then luminance is improved, but heat generation increases and lifespan decreases
Solution Approach 1:
The patent introduces a reflecting electrode layer positioned between the substrate and the organic light emitting diode. This adding a spatial dimension (reflection path) allows light to be redirected and reused, effectively increasing luminance without increasing current flow, thereby avoiding heat generation issues
Solution Approach 2:
The patent changes the optical parameters of the system by introducing a reflecting electrode with specific reflectivity characteristics. This modifies the light extraction efficiency and luminance output without requiring changes to the electrical operating parameters (current) of the OLED, thus avoiding the heat generation problem associated with high current operation
2Illumination intensity
If pentile structure with white emission layer is used to increase luminance, then luminance is improved, but device complexity increases and resolution decreases
Solution Approach 1:
The patent extracts the white emission function from the complex pentile structure and implements it through a simpler approach: using a reflecting electrode to enhance the light output of conventional RGB subpixels. This removes the need for additional white emission layers and complex driving schemes while achieving the desired luminance improvement
3Illumination intensity
If pentile structure with white emission layer is used to increase luminance, then luminance is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent removes the complex multi-layer white emission structure and its associated alignment requirements. Instead, it uses a reflecting electrode that can be manufactured with standard precision tolerances, eliminating the need for high-precision alignment between multiple emission layers and color filters
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 the luminance of organic light emitting diode displays, improving visibility in bright environments without the need for complex driving schemes, thereby addressing the limitations of current pentile structures.
Implementation Method 1
Each of the organic light emitting diodes emits light by energy generated when excitons generated by combining electrons and holes with each other in the organic emission layer drop from an excited state to a base state
Implementation Method 2
a reflecting electrode connected to the transistor
Data Source
AI summary
An organic light emitting diode display includes a substrate, a transistor on the substrate, a reflecting electrode connected to the transistor, a color filter on the reflecting electrode, a first electrode on the color filter and electrically connected to the reflecting electrode, a pixel definition layer on the color filter and having an opening exposing the first electrode, a white emission layer in the opening and a second electrode on the white emission layer.