Anthracene Derivative for Homogeneous Light Emission Stability
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Solution Overview
Problem
Existing organic electroluminescence (EL) devices face challenges in achieving homogeneous light emission over a long period and maintaining a long lifetime due to issues like exciplex formation, short light emission duration, and electrode separation, particularly when using materials with low melting points such as pyrazine, quinoline, and quinoxaline compounds.
Innovation Solution
The use of an anthracene derivative with a heteroaryl group containing a nitrogen-containing six-membered ring, specifically in the form of Formula (1) or (2), as a material for organic EL devices, which is incorporated into the device structure as a single component or mixed component in organic thin layers between the cathode and anode, enhancing light emission stability and longevity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pyrazine, quinoline, and quinoxaline compounds are used as constitutional components for organic EL devices, then current efficiency is enhanced, but the materials crystallize soon due to low melting point and scarcely emit light
Solution Approach 1:
The patent modifies the molecular structure of pyrazine, quinoline, and quinoxaline compounds by introducing specific substituents and fusion rings to elevate their melting points. This structural parameter change prevents crystallization while maintaining the materials' ability to enhance current efficiency in organic EL devices.
Solution Approach 2:
The invention creates composite molecular structures by combining nitrogen-containing six-membered rings with other aromatic rings and substituents. These composite structures achieve both high melting points (preventing crystallization) and sustained light emission capability, resolving the contradiction between current efficiency enhancement and emission stability.
2Illumination intensity
If electron injecting layer is introduced to enhance current efficiency, then light emission at high luminance is obtained, but lifetime is shortened due to electrode separation and crystallization
Solution Approach 1:
The patent changes the melting point parameter of electron injecting layer materials through molecular structure modification. By elevating the melting point above the device operating temperature, the materials remain amorphous and prevent electrode separation, thereby extending device lifetime while maintaining high luminance output.
Solution Approach 2:
The invention replaces short-lived crystalline materials with long-lived amorphous materials having high melting points. This substitution eliminates the crystallization issue that limited device lifetime, enabling sustained high luminance emission over extended periods.
3Stability of the object's composition
If materials with low melting point are used in amorphous thin film layer, then homogeneous light emission is achieved, but crystallization occurs soon and light emission is lost
Solution Approach 1:
The patent fundamentally changes the melting point parameter of the materials used in the amorphous thin film layer. By selecting or synthesizing materials with melting points significantly higher than the device operating temperature, the amorphous state remains stable over time, preventing crystallization and maintaining homogeneous light emission for extended durations.
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 anthracene derivative enables organic EL devices to achieve homogeneous light emission for an extended duration and extends the device's lifetime by preventing crystallization and electrode separation, thereby improving the overall performance and durability of the device.
Implementation Method 1
the above matters to use pyrazine compounds, quinoline compounds and quinoxaline compounds... however, involved therein was the problem that the above compounds had a low melting point and therefore were crystallized soon
Implementation Method 2
An organic electroluminescence (EL) device is a spontaneous light emitting device making use of the principle that a fluorescent substance emits light by recombination energy of holes injected from an anode and electrons injected from a cathode by applying an electric field
Data Source
AI summary
Provided are an anthracene derivative having a heteroaryl group containing a nitrogen-containing six-membered ring and having a specific structure and an organic electroluminescence device in which an organic thin film layer comprising a single layer or plural layers including at least a light emitting layer is interposed between a cathode and an anode, wherein at least one layer in the above organic thin film layer contains the anthracene derivative described above in the form of a single component or a mixed component. Provided are the organic electroluminescence device in which homogeneous light emission is obtained over a long period of time and which has a long lifetime and the anthracene derivative which materializes the same.