OLED First Electrode Embossing Pattern Light Extraction
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Solution Overview
Problem
Conventional lighting technologies, such as incandescent and fluorescent lamps, face issues with low energy efficiency and environmental concerns, while LED lighting has limited light emitting efficiency due to narrow peak widths, and OLEDs aim to improve this by maximizing light emitting areas through innovative electrode designs.
Innovation Solution
The OLED lighting apparatus employs a high refractive transparent conductive material first electrode with an embossing pattern at the interface between the substrate and overcoat layer, enhancing light extraction efficiency through a microlens effect, eliminating the need for a light extraction layer and reducing manufacturing costs, and allowing light emission in non-light emitting areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional flat first electrode is used, then the manufacturing process is simple, but the light extraction efficiency is low
Solution Approach 1:
The first electrode is formed with a microlens embossing pattern featuring convex curved surfaces instead of a flat structure. This curvature creates optical focusing effects that enhance light extraction efficiency by redirecting internally reflected photons toward the emission direction, resolving the contradiction between manufacturing simplicity and light extraction performance.
Solution Approach 2:
The refractive index of the first electrode material is increased to a high refractive index range (2.0-2.5), and the embossing pattern parameters (depth, diameter, spacing) are optimized. These parameter changes improve light extraction efficiency by enhancing the microlens effect while maintaining compatibility with existing manufacturing processes.
2Loss of energy
If a light extraction layer is added at the substrate interface, then the light extraction efficiency is improved, but the manufacturing complexity and cost increase
Solution Approach 1:
The light extraction function is merged into the first electrode by forming a microlens embossing pattern directly on it. This integration eliminates the need for a separate light extraction layer, reducing manufacturing complexity while maintaining improved light extraction efficiency through the embossing pattern's optical effects.
Solution Approach 2:
The first electrode is designed to serve multiple functions: electrical conduction, optical transparency, and light extraction enhancement through the embossing pattern. This multi-functionality eliminates the need for dedicated light extraction layers, simplifying the overall device structure while achieving the desired optical performance.
3Ease of manufacture
If the first electrode covers only the light emitting area, then the manufacturing process is simpler, but the overall light extraction efficiency is limited
Solution Approach 1:
The first electrode is extended from covering only the light emitting area to covering the entire active area including non-light emitting regions. This dimensional expansion allows light extraction enhancement in previously inactive areas, improving overall light extraction efficiency while maintaining manufacturing simplicity through a unified electrode 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 improves light extraction efficiency, extends the lifetime of the OLED lighting apparatus, and enhances color rendering properties by maximizing the light emitting area, while reducing process yield and manufacturing costs.
Implementation Method 1
improve light extraction efficiency through a light scattering due to a microlens effect through the first electrode provided with the embossing pattern
Implementation Method 2
improve light extraction efficiency through a light scattering due to a microlens effect through the first electrode provided with the embossing pattern
Implementation Method 3
a first electrode, which is provided with an embossing pattern at an interface, with which an overcoat layer on the substrate is contacted, and made of a high refractive transparent conductive material
Data Source
AI summary
An organic light emitting diode (OLED) lighting apparatus capable of improving lighting efficiency and lifetime by maximizing a light emitting area is disclosed. The OLED lighting apparatus may include a first electrode, which is provided with an embossing pattern at an interface at which the first electrode contacts an overcoat layer on a substrate. The first electrode may be made of a high refractive transparent conductive material, and may be arranged in an entire active area of the OLED lighting apparatus. The OLED lighting apparatus can improve light extraction efficiency through a light scattering due to a microlens effect through the first electrode provided with the embossing pattern, which facilitates elimination of a light extraction layer arranged at the interface between the substrate and the overcoat layer, thereby reducing a process yield and manufacturing cost.