Dual Blue Emitting Layer OLED for Color Purity and Lifespan
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Solution Overview
Problem
The blue pixel in OLEDs does not provide sufficient emitting efficiency, color purity, and lifespan, limiting the performance of organic light emitting display devices.
Innovation Solution
The OLED includes a first and second blue emitting layer with specific host and dopant compositions, where the first blue emitting layer contains a pyrene derivative as the host and a compound represented by Formula 5 or 6 as the dopant, and the second blue emitting layer contains an anthracene derivative as the host and a compound represented by Formula 5 or 6 as the dopant, with varying weight percentages and thicknesses of these layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional single blue emitting layer is used in OLED, then the device structure is simple, but the emitting efficiency, color purity and lifespan are insufficient
Solution Approach 1:
The blue emitting layer is divided into two separate layers: a first blue emitting layer comprising a pyrene derivative host and a first dopant, and a second blue emitting layer comprising an anthracene derivative host and a second dopant. This segmentation allows each layer to contribute different properties, improving overall emitting efficiency and lifespan while maintaining color purity.
Solution Approach 2:
The patent employs composite material strategy by combining two different host materials (pyrene derivative and anthracene derivative) with their respective dopants in separate emitting layers. This composite approach leverages the complementary properties of different organic materials to achieve superior emitting performance compared to single-material layers.
2Reliability
If a conventional single blue emitting layer is used in OLED, then the device structure is simple, but the color purity is insufficient
Solution Approach 1:
The blue emitting layer is divided into two separate layers: a first blue emitting layer comprising a pyrene derivative host and a first dopant, and a second blue emitting layer comprising an anthracene derivative host and a second dopant. This segmentation allows each layer to contribute different properties, improving overall emitting efficiency and lifespan while maintaining color purity.
Solution Approach 2:
Each blue emitting layer is designed with specific local quality characteristics: the first layer uses pyrene derivative host optimized for certain emitting properties, while the second layer uses anthracene derivative host with different optimized properties. This local quality differentiation enables superior color purity through the combination of layers.
3Productivity
If a conventional single blue emitting layer is used in OLED, then the device structure is simple, but the emitting efficiency is insufficient
Solution Approach 1:
The blue emitting layer is divided into two separate layers: a first blue emitting layer comprising a pyrene derivative host and a first dopant, and a second blue emitting layer comprising an anthracene derivative host and a second dopant. This segmentation allows each layer to contribute different properties, improving overall emitting efficiency and lifespan while maintaining color purity.
Solution Approach 2:
The patent employs composite material strategy by combining two different host materials (pyrene derivative and anthracene derivative) with their respective dopants in separate emitting layers. This composite approach leverages the complementary properties of different organic materials to achieve superior emitting performance compared to single-material layers.
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 driving voltage, color purity, and lifespan of the OLED, improving the overall performance of the organic light emitting device.
Implementation Method 1
The OLED emits light by injecting electrons from a cathode as an electron injection electrode and holes from an anode as a hole injection electrode into an emitting material layer (EML), combining the electrons with the holes, generating an exciton, and transforming the exciton from an excited state to a ground state
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present invention relates to an organic light emitting diode comprising a first electrode; a second electrode facing the first electrode; and a first emitting part including a first blue emitting layer and a second blue emitting layer and positioned between the first and second electrode, the second blue emitting layer positioned between the first blue emitting layer and the second electrode and contacting the first blue emitting layer, wherein the first blue emitting layer includes a first host and a first dopant, and the second blue emitting layer includes a second host and a second dopant, wherein the first host is a pyrene derivative, and the second host is an anthracene derivative, wherein the first dopant is a first compound represented by Formula 5 or a second compound represented by Formula 6, and the second dopant is a third compound represented by Formula 5 or a fourth compound represented by Formula 6.