OLED Electroluminescent Material for Electron-Hole Balance
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Solution Overview
Problem
Current organic electroluminescent (OLED) devices face challenges such as low internal quantum efficiency, short device lifetime, and high operating voltage, particularly in blue phosphorescent devices. Additionally, there is a need for materials with deep LUMO energy levels, high stability, and good film formation properties for use in hole injection layers.
Innovation Solution
Development of novel organic electroluminescent materials with a dehydrogenated ring structure, which have LUMO energy levels with different depths and suitable evaporation temperatures. These materials can be used independently as hole injection layers or as P-type dopants, improving the balance of electrons and holes in OLED devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If phosphorescent emitters are used in OLEDs, then internal quantum efficiency can reach 100%, but device lifetime is shortened and operating voltage increases, especially in blue phosphorescent devices
Solution Approach 1:
The patent modifies the molecular structure of phosphorescent emitters by introducing specific substituents and adjusting the coordination environment of heavy metal complexes, thereby changing photophysical parameters such as triplet energy levels and spin-orbit coupling constants to improve device lifetime while maintaining high efficiency
Solution Approach 2:
The patent employs composite material systems combining phosphorescent emitters with specific host materials and dopants, creating optimized layer structures that simultaneously achieve high internal quantum efficiency and extended device lifetime by separating the functions of light emission and charge transport
2Use of energy by moving object
If phosphorescent emitters are used in OLEDs, then internal quantum efficiency can reach 100%, but operating voltage becomes excessively high, especially in blue phosphorescent devices
Solution Approach 1:
The patent adjusts energy level parameters of the phosphorescent emitter and surrounding materials, specifically optimizing HOMO-LUMO gaps and triplet energy levels to reduce charge injection barriers and lower operating voltage while preserving high internal quantum efficiency
3Ease of manufacture
If conventional hole injection layer materials are used, then device fabrication is simplified, but materials lack deep LUMO energy levels, high stability, and good film formation properties
Solution Approach 1:
The patent systematically modifies the chemical structure of hole injection layer materials by introducing electron-withdrawing groups and adjusting molecular weight, thereby achieving deep LUMO energy levels and enhanced thermal stability while maintaining solution processability and film formation quality
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 proposed materials enhance the external quantum efficiency, current efficiency, and lifetime of OLED devices, making them suitable for various types of semiconductor devices, including fluorescent OLEDs, phosphorescent OLEDs, and white OLEDs.
Implementation Method 1
The compound of Formula 1 and its application to the organic electroluminescent device can improve the transport balance of electrons and holes in the device
Implementation Method 2
Once a bias is applied to the device, green light was emitted from the device
Data Source
AI summary
Disclosed are a novel organic electroluminescent material and a device thereof. Such a novel organic electroluminescent material has a structure of Formula 1, and when applied to the organic electroluminescent device, can improve the balance of electrons and holes in the organic electroluminescent device and thus bring excellent device effects such as the improvement of external quantum efficiency, current efficiency, and service life. The novel organic electroluminescent material can be used to prepare organic semiconductor devices and is suitable for different types of organic semiconductor devices, including but not limited to fluorescent OLEDs, phosphorescent OLEDs, white OLEDs, laminated OLEDs, OTFTs, OPVs, etc. Further disclosed are an electroluminescent device comprising the organic electroluminescent material and a compound formulation comprising the organic electroluminescent material.