Nitrogen-Containing OLED Material for Low-Voltage Electron Blocking
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Solution Overview
Problem
Current organic electroluminescence devices face limitations in performance, particularly in reducing working voltage, enhancing efficiency, and extending lifespan, due to the need for improved materials in the hole transport and electron blocking layers.
Innovation Solution
A nitrogen-containing compound with a specific structure, featuring a 5-phenyl-9,9-dimethylfluorenyl-3-yl parent nucleus and arylamino linkage, is introduced to create a strong conjugation effect, deepening the highest occupied molecular orbital (HOMO) energy level and increasing hole mobility, which is used in an electron blocking layer to reduce voltage and enhance device performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional hole transport materials are used, then the device can operate, but the working voltage is high and efficiency is low
Solution Approach 1:
The patent modifies the molecular structure parameters of hole transport materials by introducing specific substituents (e.g., dibenzofuran, carbazole groups) and adjusting molecular weight, which changes the electronic properties (HOMO energy level, hole mobility) to reduce working voltage and improve efficiency
Solution Approach 2:
The patent creates composite molecular structures by combining different functional groups (aromatic hydrocarbons, heterocyclic compounds, amino groups) to achieve synergistic effects that simultaneously lower working voltage and enhance device efficiency
2Duration of action of moving object
If conventional electron blocking layer materials are used, then the device can function, but the lifespan is limited
Solution Approach 1:
The patent introduces specific functional groups (e.g., electron-deficient groups like dibenzofuran) at strategic positions in the molecule to create local electron-blocking regions that prevent detrimental electron back-transfer to the light-emitting layer, thereby extending device lifespan while maintaining stability
3Speed
If materials with high electron cloud density are used, then hole mobility increases, but molecular interaction increases which may reduce amorphous form stability
Solution Approach 1:
The patent introduces bulky substituents (e.g., tert-butyl groups, adamantyl groups) at specific positions to create local steric hindrance that prevents excessive molecular stacking and crystallization, maintaining amorphous stability while preserving high hole mobility through the core conjugated structure
Solution Approach 2:
The patent employs asymmetric molecular designs where substituents are placed at non-equivalent positions on the aromatic core, creating directional intermolecular interactions that favor amorphous packing over crystalline structures while maintaining efficient charge transport pathways
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 nitrogen-containing compound effectively reduces the working voltage, improves luminous efficiency, and extends the lifespan of organic electroluminescence devices by promoting amorphous morphology and film-forming characteristics, leading to increased efficiency and prolonged device life.
Implementation Method 1
The linkage of the arylamino to the position 3 of dimethylfluorenyml can produce a strong conjugation effect to increase a density of local electron cloud, such that a material can have both a deep highest occupied molecular orbital (HOMO) energy level and a high hole mobility
Implementation Method 2
When used in an electron blocking layer of an organic electroluminescence device, the material can effectively reduce a working voltage of the device, enhance the efficiency of the device, and improve a life span of the device
Implementation Method 3
Organic electroluminescence devices, also known as organic light-emitting diodes (OLEDs), refer to the phenomenon that organic light-emitting materials are excited by a current to emit light under the action of an electric field. The phenomenon refers to a process of converting electrical energy into optical energy
Implementation Method 4
There is a large twist angle between the 5-substituted phenyl and the dimethylfluorenyml, such that an interaction between molecules can be effectively reduced while basically maintaining the morphology of molecules themselves, thereby enhancing an amorphous form of the material and improving the film-forming characteristics of the material
Data Source
AI summary
The present application belongs to the technical field of organic materials and provides a nitrogen-containing compound, an electronic component, and an electronic device. The nitrogen-containing compound has a structure shown in Chemical formula 1: