Blue OLED Layer Stack Using Deuterated Anthracene Hosts
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Solution Overview
Problem
The blue pixel in organic light emitting display devices does not provide sufficient emitting efficiency and lifespan, limiting the overall performance of the OLED.
Innovation Solution
The OLED structure includes a first and second blue emitting layer with specific anthracene derivative hosts and dopants, along with electron transporting layers, to enhance efficiency and lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional emitting materials are used in blue pixels, then device complexity is reduced, but emitting efficiency and lifespan are insufficient
Solution Approach 1:
The emitting layer is divided into multiple distinct layers (first emitting layer, second emitting layer, third emitting layer) with different functions. The first emitting layer focuses on high efficiency, the second on stability, and the third on color purity, allowing each layer to be optimized independently for its specific function while collectively solving the lifespan and efficiency problems
Solution Approach 2:
Each emitting layer uses composite material systems with specific host-guest combinations. The first emitting layer uses host material 1 with guest material 1, the second uses host material 2 with guest material 2, and the third uses host material 3 with guest material 3. These composite material systems provide synergistic effects that improve overall device reliability without excessive complexity
2Productivity
If conventional emitting materials are used in blue pixels, then manufacturing process is simplified, but emitting efficiency is insufficient
Solution Approach 1:
Different regions of the emitting layer structure are assigned different material compositions and properties. The first emitting layer near the hole injection electrode uses materials optimized for high efficiency and stability, the second emitting layer uses materials optimized for intermediate properties, and the third emitting layer uses materials optimized for color purity and stability. This local optimization of material properties throughout the layer structure achieves high emitting efficiency while managing complexity through systematic design
3Illumination intensity
If single emitting layer is used, then device structure is simple, but color purity and efficiency are compromised
Solution Approach 1:
The emitting layer is segmented into three distinct layers, each responsible for different aspects of light emission. The first emitting layer is optimized for high efficiency with specific host-guest combinations, the second emitting layer is optimized for stability and intermediate emission properties, and the third emitting layer is optimized for color purity. This segmentation allows each layer to specialize in one function, achieving high color purity and efficiency without requiring excessive complexity in any single layer
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 improved OLED structure enhances driving voltage, emitting efficiency, and lifespan by optimizing the blue emitting layers and electron transporting materials.
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
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AI summary
The present invention relates to an organic light emitting diode comprising first (160) and second (164) electrodes facing each other; and a first emitting part (162) including a first blue emitting layer (250), a second blue emitting layer (260), an electron transporting layer (280) and positioned between the first and second electrode, wherein the first blue emitting layer includes a first host (252) and a first dopant (254), and the second blue emitting layer includes a second host (262) and a second dopant (264), wherein the first host is an anthracene derivative having a first deuteration ratio, and the second host is an anthracene derivative having a second deuteration ratio smaller than the first deuteration ratio, wherein the first dopant is a first compound represented by Formula 3, and wherein the first electron transporting layer includes at least one of a first electron transporting material represented by Formula 9 and a second electron transporting material represented by Formula 10.