Organic EL Emission Layer Efficiency Lifetime
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Solution Overview
Problem
Current organic electroluminescent elements face challenges in achieving high emission efficiency and long emission lifetime, particularly when using phosphorescent materials, with existing iridium complexes and platinum complexes showing insufficient light emission efficiency and lifetime.
Innovation Solution
The development of an organic electroluminescent element with an emission layer comprising specific compounds represented by Formula (2), which include substituents such as carbazolyl and diarylamino groups, and a phosphorescence-emitting metal complex, specifically an Ir complex, to enhance emission efficiency and lifetime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If phosphorescent materials (iridium complexes, platinum complexes) are used in organic electroluminescent elements, then internal quantum efficiency can reach 100%, but light emission efficiency and emission lifetime are insufficient
Solution Approach 1:
The patent changes the chemical structure parameters of the host compound by introducing specific substituents (carbazolyl group, diarylamino group) at defined positions in the molecular structure. This structural parameter change leads to improved triplet energy level and enhanced phosphorescence emission lifetime while maintaining high internal quantum efficiency
Solution Approach 2:
The patent creates a composite emission layer system combining a specifically designed host compound (with carbazolyl and diarylamino groups) and phosphorescent dopant (iridium or platinum complex). This composite material approach allows the host to provide structural stability and appropriate energy levels while the dopant provides phosphorescence emission, resolving the contradiction between efficiency and lifetime
2Device complexity
If conventional host compounds are used with phosphorescent dopants, then element structure is simple, but light emission efficiency is insufficient
Solution Approach 1:
The patent optimizes key parameters of the host compound including triplet energy level (Et), HOMO level, and LUMO level by introducing specific functional groups. The triplet energy level is designed to be higher than the phosphorescent dopant to prevent energy back-transfer, while HOMO and LUMO levels are optimized for efficient charge injection and carrier transport, thereby improving light emission efficiency without significantly increasing structural complexity
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
This configuration results in high light emission efficiency and extended light emission life, making the organic electroluminescent element suitable for display and lighting devices with improved performance.
Implementation Method 1
an organic electroluminescent element with an emission layer comprising specific compounds represented by Formula (2), which include substituents such as carbazolyl and diarylamino groups, and a phosphorescence-emitting metal complex
Implementation Method 2
Organic electroluminescent device
Data Source
Figure 1(a)~1(e)
AI summary
Disclosed is an organic EL device wherein an emission wavelength is controlled. The organic EL device has high luminous efficiency and long emission life. Also disclosed are an illuminating device and a display.