Ortho-Substituted Fused-Ring OLED Materials for High Sublimation Yield
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current p-type doping materials for OLEDs have low sublimation yields due to extreme electron deficiency and strong oxidative properties, which affects their performance and production costs in organic electroluminescent devices.
Innovation Solution
Development of ortho-substituted dehydrogenated fused-ring compounds with high sublimation yields, used as charge transporting and injection materials in OLEDs, enhancing their performance by providing low voltage, high current efficiency, and high external quantum efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional p-type doping materials are used in OLEDs, then charge transporting function is achieved, but sublimation yield is low due to extreme electron deficiency and strong oxidative properties
Solution Approach 1:
The patent modifies the molecular structure parameters of p-type doping materials by introducing ortho-substituted dehydrogenated fused-ring structures with specific substituents (Formula 2-1 to 2-10), which changes the electronic properties to reduce extreme electron deficiency while maintaining charge transporting function, thereby improving sublimation yield
Solution Approach 2:
The patent creates composite molecular structures by combining dehydrogenated fused-ring cores with various substituents (Ar1, R1, R2 groups), forming new compound classes that exhibit both good charge transporting properties and high sublimation yields, resolving the contradiction between functionality and material productivity
2Reliability
If strong oxidative p-type doping materials are used, then charge injection capability is enhanced, but material stability and device lifetime are reduced
Solution Approach 1:
The patent adjusts the oxidative strength parameter of doping materials by modifying the dehydrogenated fused-ring structure with electron-donating or electron-withdrawing substituents, achieving optimal balance between charge injection capability and material stability for extended device lifetime
Solution Approach 2:
The patent introduces specific substituent groups at particular positions (ortho-substitution pattern) on the molecular structure to locally modify electronic properties, enabling regions of the molecule to have different oxidative characteristics that balance injection capability with overall stability
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 novel compounds exhibit unexpected high sublimation yields and offer excellent performance in organic electroluminescent devices, including low voltage and high efficiency, addressing the limitations of existing p-type doping materials.
Implementation Method 1
Small molecule OLEDs are generally fabricated by vacuum thermal evaporation
Implementation Method 2
Tang and Van Slyke of Eastman Kodak reported a bilayer organic electroluminescent device
Data Source
Figure 1~2
AI summary
Provided are an organic electroluminescent material and device. The organic electroluminescent material is a novel compound having an ortho-substituted dehydrogenated fused-ring structure represented by Formula 1. The compound may be used as a charge transporting material, a charge injection material, and a similar material in an organic electroluminescent device. These novel compounds have an unexpected high sublimation yield due to a structural design. Additionally, these novel compounds can provide excellent performance for organic electroluminescent devices, such as low voltage and high efficiency. Further provided are an electroluminescent device and a compound composition.