Optical Coupling Layer Refractive Index for OLED Light Extraction
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Solution Overview
Problem
The manufacturing of organic light-emitting display panels faces increased costs due to the need for different thicknesses of optical coupling layers for pixel regions emitting different colors, which complicates the production process and reduces light extraction efficiency.
Innovation Solution
An optical coupling layer with a refractive index range of 2 to 2.3 in the blue light wavelength region and minimal refractive index differences between blue, green, and red regions is used, allowing for a single thickness to improve light extraction efficiency across all colors without the need for color-specific thicknesses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If different thicknesses of optical coupling layer are provided for pixel regions emitting different colors, then light extraction efficiency is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent changes the refractive index parameter of the optical coupling layer to a specific range (2.0-2.3) that provides optimal light extraction efficiency for blue light while maintaining acceptable performance for green and red light. This parameter optimization allows a single uniform thickness to serve all color regions, eliminating the need for color-specific thickness variations and simplifying the manufacturing process.
2Loss of energy
If different thicknesses of optical coupling layer are provided for pixel regions emitting different colors, then light extraction efficiency is improved, but manufacturing cost increases
Solution Approach 1:
The optical coupling layer is designed with universal functionality to serve all color regions (blue, green, red) simultaneously. By optimizing the refractive index to 2.0-2.3, a single layer design achieves acceptable light extraction efficiency across all wavelengths, making the layer universally applicable without requiring color-specific variations in thickness or material composition, thereby reducing manufacturing cost.
3Ease of manufacture
If a single thickness of optical coupling layer is used for all color regions, then manufacturing cost and complexity are reduced, but light extraction efficiency for some colors may be compromised
Solution Approach 1:
The refractive index parameter is optimized to a specific range (2.0-2.3) that represents a compromise solution, providing sufficient light extraction efficiency for blue light (which requires higher refractive index) while maintaining acceptable performance for green and red light. This parameter selection enables uniform thickness design across all color regions without significantly compromising overall display performance.
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 enhances light extraction efficiency for all color bands while reducing production costs and simplifying the manufacturing process by using a uniform optical coupling layer thickness for all pixel regions.
Implementation Method 1
the electrons in the cathode that may move freely will interact with the photons, so as to generate an electron dilatational wave that propagates along the surface of the cathode metal, which is called a surface plasmon polariton
Implementation Method 2
the optical coupling layer with a high refractive index may also reduce the total reflection from the cathode and coupling layer interface on the light exit side
Implementation Method 3
the optical coupling layer with a high refractive index may also reduce the total reflection from the cathode and coupling layer interface on the light exit side, lower the optical waveguide effect in the device
Data Source
AI summary
The invention discloses an organic light-emitting display panel, an electronic device and a method for manufacturing the same. The organic light-emitting display panel includes: pixel regions on a substrate which emit light of various colors; each pixel region includes a first electrode, a light-emitting functional layer and a second electrode, one of the first electrode and the second electrode is light exit side electrode(s); an optical coupling layer is set on one side of the light exit side electrode far from the light-emitting functional layer; the refractive index of the optical coupling layer in the blue light wavelength region is 2 to 2.3; the difference between the refractive index of the optical coupling layer in the blue light wavelength region and that in the green light wavelength region is less than or equal to 0.2.