OLED Pixel Electrode Insulating Layer Recessed Holes
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Solution Overview
Problem
Organic light emitting diode (OLED) displays face challenges in light extraction efficiency due to total reflection of light generated from the organic emission layer, leading to reduced utilization of emitted light.
Innovation Solution
A manufacturing method involving the formation of recessed holes on the insulating layer contacting the transparent conductive layer of the pixel electrode, using an etchant like fluoric acid and ammonium fluoride, which functions like lenses to minimize total reflection and enhance light extraction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a flat insulating layer surface is used, then the manufacturing process is simple, but light extraction efficiency is poor due to total reflection
Solution Approach 1:
The patent applies curvature by forming recessed holes (circular or arc-shaped cross-sections) in the insulating layer surface. These curved structures function as micro-lenses that refract light and reduce total internal reflection, thereby improving light extraction efficiency without significantly complicating the manufacturing process
Solution Approach 2:
The patent creates a porous structure by forming an array of recessed holes in the insulating layer. This porous configuration increases the extraction of light by providing multiple interfaces for light refraction and reducing total internal reflection, while maintaining manufacturing feasibility through standard semiconductor processing techniques
2Loss of energy
If recessed holes are formed in the insulating layer, then light extraction efficiency is improved, but the manufacturing process becomes more complex
Solution Approach 1:
The patent segments the insulating layer by creating an array of discrete recessed holes rather than modifying the entire surface uniformly. This segmentation allows light extraction improvement to be achieved through localized structural modifications that can be implemented using standard photolithography and etching processes
Solution Approach 2:
The patent modifies specific parameters of the insulating layer (creating controlled recesses with specific depths, diameters, and spacing) to optimize light extraction. These parameter changes are achieved through controlled etching processes using specific etchants, transforming the flat surface into a micro-structured surface that enhances light outcoupling
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 method effectively improves light extraction efficiency by reducing total reflection and allowing more light to be emitted in the direction of the substrate, enhancing the display's image realization and manufacturing simplicity.
Implementation Method 1
The plurality of recessed holes may function like lenses
Implementation Method 2
total reflection of light generated from the organic emission layer
Data Source
AI summary
An exemplary embodiment may include a substrate, an insulating layer on the substrate, and a pixel electrode including a transparent conductive layer on the insulating layer. A portion of a surface of the insulating layer contacting the transparent conductive layer has a plurality of recessed holes formed by etching with an etchant into an interface between the transparent conductive layer of the pixel electrode and the insulating layer.