Diazadibenzofuran Host Materials for Longer-Lived Phosphorescent OLEDs
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Solution Overview
Problem
Current organic electroluminescent devices, particularly those using phosphorescent materials, face challenges in efficiency, operating voltage, and lifetime, with existing matrix and electron transport materials not adequately addressing these issues.
Innovation Solution
Development of specific diazadibenzofuran or diazadibenzothiophene derivatives with tailored structures for use as matrix and electron transport materials in organic electroluminescent devices, enhancing solubility, film formation, and oxidation stability, and improving the glass transition temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing matrix materials and electron transport materials are used in phosphorescent OLEDs, then device fabrication is straightforward, but device lifetime, efficiency, and operating voltage are insufficient
Solution Approach 1:
The patent modifies the chemical structure of matrix materials by introducing specific substituents (e.g., carbazole groups, dibenzofuran groups, dibenzothiophene groups) to diazadibenzofuran cores, thereby changing molecular parameters such as HOMO/LUMO levels, triplet energy, and glass transition temperature to achieve improved device lifetime and efficiency
Solution Approach 2:
The patent develops composite molecular structures combining multiple functional groups (diazadibenzofuran core with carbazole, dibenzofuran, or dibenzothiophene substituents) to create materials that simultaneously provide electron transport, matrix functions, and improved stability properties
2Use of energy by moving object
If organometallic phosphorescent emitters are used to achieve high energy efficiency, then power efficiency improves up to four times, but device operating voltage and lifetime remain insufficient
Solution Approach 1:
The patent optimizes the energy level parameters (HOMO/LUMO levels and triplet energy) of the matrix material to better match the phosphorescent emitter, improving energy transfer efficiency and reducing energy loss, thereby extending device lifetime while maintaining high power efficiency
3Power
If diazadibenzofuran derivatives with carbazole groups are used as matrix materials, then electron transport capability improves, but device lifetime and efficiency remain insufficient without proper substitution patterns
Solution Approach 1:
The patent introduces specific substitution patterns where carbazole groups are positioned at particular locations on the diazadibenzofuran core, creating local regions with optimized electron density and HOMO/LUMO levels to enhance electron transport while maintaining overall molecular stability
Solution Approach 2:
The patent systematically varies the substitution pattern and type of groups attached to the diazadibenzofuran core to optimize the balance between electron transport capability (power) and device lifetime by controlling molecular energy levels and glass transition temperature
4Productivity
If materials with improved efficiency are developed, then device performance increases, but material synthesis complexity increases
Solution Approach 1:
The patent divides the molecular structure into distinct functional segments (diazadibenzofuran core, carbazole groups, dibenzofuran groups, dibenzothiophene groups) that can be independently selected and combined, allowing systematic optimization of efficiency while managing structural complexity through modular design
Data Source
AI summary
The present invention describes diazadibenzofuran or diazadibenzothiophene derivatives substituted by carbazole, fluorene, phenanthrene, benzofuran and/or benzothiophene groups, especially for use in electronic devices. The invention further relates to a process for preparing the compounds of the invention and to electronic devices comprising these.