Composite Host Materials for OLED Driving Voltage and Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current organic electroluminescent devices face challenges in achieving improved driving voltage, luminous efficiency, and lifespan characteristics, with existing materials not meeting practical requirements for enhanced performance.
Innovation Solution
A combination of specific host compounds, represented by formulas 1, 2, 3, and 4, are used to form a plurality of host materials that improve the performance of organic electroluminescent devices by reducing driving voltage and increasing luminous efficiency and lifespan, comprising aryl and heteroaryl groups with various substituents and linkages, allowing for their use in light-emitting layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional host materials are used in OLED, then device structure is simple, but driving voltage is high and luminous efficiency is low
Solution Approach 1:
The patent employs composite host materials comprising a first host compound (formula 1) and a second host compound (formula 2) in specific weight ratios. The first host compound contains aryl/heteroaryl groups with electron-donating or electron-withdrawing substituents, while the second host compound contains carbazole or triphenylene core structures. This composite approach enables optimization of both driving voltage and luminous efficiency by combining the advantageous properties of different material classes, resolving the contradiction between simple structure and improved power performance.
Solution Approach 2:
The patent systematically varies key parameters including molecular weight (150-500 Da for first host, 200-600 Da for second host), substituent types (electron-donating groups like alkyl/arylamino, electron-withdrawing groups like cyano/carboxyl), and weight ratios (95:5 to 50:50) to achieve optimal balance between driving voltage reduction and luminous efficiency enhancement, demonstrating parameter optimization to resolve the technical contradiction.
2Reliability
If conventional host materials are used in OLED, then manufacturing process is simple, but luminous efficiency is low and lifespan is short
Solution Approach 1:
The patent optimizes molecular weight parameters within specific ranges (150-500 Da for first host, 200-600 Da for second host) to balance lifespan enhancement with manufacturability. These controlled parameter adjustments ensure materials maintain reasonable synthesis complexity while achieving improved reliability through optimized molecular structures that reduce degradation pathways.
Solution Approach 2:
By combining first host compounds with aryl/heteroaryl cores and second host compounds with carbazole/triphenylene structures in controlled ratios, the patent creates composite materials that enhance lifespan through synergistic effects while maintaining compatibility with existing manufacturing processes. The composite structure provides both improved reliability and feasibility for industrial production.
3Loss of energy
If phosphorescent materials are used to improve luminous efficiency, then luminous efficiency increases, but driving voltage increases and lifespan decreases
Solution Approach 1:
The patent uses composite host materials as an alternative approach to phosphorescent materials, combining first host compounds (formula 1) with aryl/heteroaryl groups and second host compounds (formula 2) with carbazole or triphenylene cores. This composite organic host system achieves improved luminous efficiency through enhanced exciton utilization while maintaining lower driving voltages and extended lifespan through the specific molecular structures and their synergistic interactions in the light-emitting layer.
Data Source
AI summary
The present disclosure relates to a plurality of host materials comprising a first host material comprising a compound represented by formula 1 and a second host material comprising a compound represented by formula 2, an organic electroluminescent compound represented by formula 3 and formula 4, and an organic electroluminescent device comprising the same.