OLED Microcavity Emission Layer Merging for Cost Reduction
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Solution Overview
Problem
Conventional organic light emitting diode (OLED) displays that emit white light require a complex process with multiple emission layers, increasing manufacturing cost and time, and result in higher power consumption due to increased driving voltage.
Innovation Solution
An OLED display structure with a microcavity structure using a first and second emission layer, where the light emitting assistance layer is selectively positioned between the emission layers, and a color transformation matrix converts light from the first and second emission layers into green light, reducing the number of masks and thickness of the organic emission layer, thereby decreasing manufacturing costs and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If three emission layers are deposited to emit white light, then the display can show full color, but the manufacturing cost and time increase due to complex processes with separate masks
Solution Approach 1:
The patent merges the functions of three separate emission layers (red, green, blue) into a single emission layer that can emit all three colors simultaneously through phosphorescent materials with different lifetimes, eliminating the need for three separate deposition processes and masks
Solution Approach 2:
The emission layer is designed to perform multiple functions - emitting red, green, and blue light - through a single layer structure using phosphorescent dopants with different phosphorescent lifetimes, making the layer universal for full-color display without requiring separate specialized layers
2Adaptability or versatility
If three emission layers are deposited to emit white light, then the display can show full color, but the manufacturing time increases due to complicated processes
Solution Approach 1:
The patent combines three separate emission layer deposition processes into a single emission layer deposition process, where the layer contains phosphorescent materials with different lifetimes that emit red, green, and blue light, thereby tripling the manufacturing speed while maintaining full-color capability
3Adaptability or versatility
If three emission layers are deposited, then the organic emission layer thickness increases, but the driving voltage increases by two to five times, causing power consumption to increase
Solution Approach 1:
The patent merges three emission layers into one emission layer with phosphorescent materials of different lifetimes, reducing the organic emission layer thickness to one-third of the conventional structure, which consequently reduces the driving voltage by two to five times and significantly lowers power consumption
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 proposed solution reduces manufacturing time and cost, improves driving efficiency, and enhances light efficiency and color reproducibility by using a microcavity structure and color transformation matrix, allowing for efficient emission of red, blue, and green lights without the need for separate emission layers for each color.
Implementation Method 1
an organic light emitting element having a first electrode, a second electrode, and an organic emission layer positioned between the first electrode and the second electrode, and the organic light emitting element emits light of various colors according to the kind of materials forming the organic emission layer
Implementation Method 2
a color transformation matrix positioned in a third region neighboring the second region and configured to convert the wavelength of the light emitted from the first emission layer and the second emission layer
Data Source
AI summary
An organic light emitting diode (OLED) display includes: a substrate; a first electrode on the substrate; a first emission layer on the first electrode; a second emission layer on the first emission layer; a second electrode on the second emission layer; and a light emitting assistance layer selectively positioned between the first emission layer and the second emission layer.