OLED Charge-Transport Material for Lower Voltage and Longer Life
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Solution Overview
Problem
Existing organic electroluminescence devices lack effective charge-transporting materials, particularly electron-transporting materials, and charge-blocking materials, such as hole-blocking materials, which affect the performance in terms of lifetime and driving voltage.
Innovation Solution
Development of compounds represented by formula (I), which can be used as charge-transporting or charge-blocking materials, specifically electron-transporting and hole-blocking materials, to enhance the performance of organic electroluminescence devices, including improved thermal stability and reduced driving voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electron-transporting materials are used in organic EL devices, then device operation is maintained, but lifetime is short and driving voltage is high
Solution Approach 1:
The patent applies parameter changes by modifying the molecular structure of electron-transporting materials through specific chemical substitutions (introducing Az groups at defined positions on aromatic hydrocarbon cores). This structural parameter modification optimizes electron mobility and energy level alignment, resulting in reduced driving voltage and extended device lifetime simultaneously.
Solution Approach 2:
The invention employs composite material design by combining specific aromatic hydrocarbon backbone structures with nitrogen-containing heteroaryl (Az) substituents. This composite approach creates materials with synergistic properties: the hydrocarbon core provides structural stability and the Az groups provide electron-transporting capability, achieving both low driving voltage and high reliability.
2Stability of the object's composition
If existing charge-transporting materials are used, then basic device function is achieved, but thermal stability is insufficient
Solution Approach 1:
The patent modifies thermal stability parameters by selecting aromatic hydrocarbon cores with high ring atom counts (6-30 atoms) and specific structural configurations. These parameter choices inherently provide higher thermal stability while the introduced Az groups maintain charge transport performance through their electron-accepting properties and molecular orbital characteristics.
Solution Approach 2:
The composite material structure combines thermally stable aromatic hydrocarbon frameworks with functionally active Az substituents. The hydrocarbon core provides thermal stability through its rigid, extended π-system, while the Az groups contribute to charge transport, achieving both requirements simultaneously.
3Reliability
If new compound structures are developed to improve performance, then device characteristics improve, but material synthesis complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the molecule into distinct functional segments: a stable aromatic hydrocarbon core and separable Az substituent groups. This modular structure allows independent optimization of each segment and facilitates synthesis through stepwise assembly, reducing overall complexity while maintaining high performance.
Solution Approach 2:
The invention achieves universality by designing a platform structure where the aromatic hydrocarbon core can accommodate various Az substituents at specific positions. This multi-functional design allows a single core structure to generate multiple high-performance materials with slightly different properties, reducing the need to develop entirely new complex structures for each application.
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 compounds of formula (I) provide organic electroluminescence devices with enhanced performance, characterized by a longer lifetime and lower driving voltage, and can be applied in various organic electronic devices beyond OLEDs.
Implementation Method 1
the electron transport layer contains a compound represented by formula (I)... the compounds of formula (I) provide organic electroluminescence devices with enhanced performance
Implementation Method 2
can be used as charge-transporting or charge-blocking materials, specifically electron-transporting and hole-blocking materials
Implementation Method 3
When a voltage is applied to an organic electroluminescence device, holes are injected to an emitting layer from an anode and electrons are injected to an emitting layer from a cathode. In the emitting layer, injected holes and electrons are re-combined and excitons are formed.
Data Source
AI summary
Specific compounds represented by formula (I), a material for an organic electroluminescence device comprising said specific compound, an organic electroluminescence device comprising said specific compound, an electronic equipment comprising said organic electroluminescence device and the use of said compounds in an organic electroluminescence device.