Fluorenylamine Host Material for OLED Thermal Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing organic light emitting devices require compounds with high thermal stability, large band gap, and high lowest excited triplet level, which Compound 1 from Patent Literature 1 does not adequately provide.
Innovation Solution
A fluorenylamine compound with three fluorenyl groups bonded to a nitrogen atom at the 3-positions, offering high glass transition temperature, thermal stability, and a large band gap, suitable for use as a host material in light emitting layers for enhanced efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If Compound 1 is used as the organic compound, then thermal stability is improved, but band gap and lowest excited triplet level are insufficient
Solution Approach 1:
The patent changes the molecular structure parameters by introducing three fluorenyl groups bonded to a nitrogen atom at the 3-positions, which simultaneously achieves high thermal stability (glass transition temperature of 150°C or higher) and large band gap (2.8 eV or more) with high lowest excited triplet level (2.5 eV or more)
Solution Approach 2:
The patent creates a composite molecular structure combining three fluorenymine groups with a central nitrogen atom, forming a novel compound that integrates multiple functional properties (thermal stability, large band gap, high triplet level) into a single material system
2Temperature
If Compound 1 is used as the organic compound, then thermal stability is improved, but lowest excited triplet level is insufficient
Solution Approach 1:
The patent changes the molecular structure parameters by introducing three fluorenymine groups bonded to a nitrogen atom at the 3-positions, which simultaneously achieves high thermal stability (glass transition temperature of 150°C or higher) and large band gap (2.8 eV or more) with high lowest excited triplet level (2.5 eV or more)
3Use of energy by moving object
If the organic compound layer is formed, then light emission function is achieved, but triplet exciton quenching occurs reducing efficiency
Solution Approach 1:
The patent converts the potential harmful effect of triplet exciton quenching into a benefit by designing a compound with inherently high lowest excited triplet level (2.5 eV or more), which prevents quenching and allows efficient light emission while maintaining thermal stability
Solution Approach 2:
The patent changes the molecular structure parameters by introducing three fluorenymine groups bonded to a nitrogen atom at the 3-positions, which simultaneously achieves high thermal stability (glass transition temperature of 150°C or higher) and large band gap (2.8 eV or more) with high lowest excited triplet level (2.5 eV or more)
Data Source
AI summary
A novel fluorenylamine compound represented by a general formula below, where R1 to R6 are each independently selected from a hydrogen atom and alkyl groups; R21 to R23 are each independently selected from a hydrogen atom and the alkyl groups; and the alkyl groups are a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group.