Organic Electroluminescent Element Using Spirofluorene Carbonyl Compounds
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Solution Overview
Problem
Organic electroluminescent elements face challenges in enhancing durability and emission efficiency while reducing the required driving voltage, particularly when combined with light-emitting materials of shorter emission wavelengths.
Innovation Solution
An organic electroluminescent element comprising a pair of electrodes with at least one organic layer containing specific compounds represented by formulas (I) to (V), which include platinum or iridium complexes as triplet light-emitting materials, with a lowest excited triplet energy level between 65 kcal/mol and 95 kcal/mol and a glass transition temperature between 130°C and 400°C, to improve efficiency and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional organic electroluminescent elements use standard organic compounds, then the structure is simple, but the emission efficiency and durability are insufficient
Solution Approach 1:
The patent uses composite organic compounds containing both spirofluorene skeletons and carbonyl groups, combining the structural stability of spirofluorene with the light-emitting properties of carbonyl-containing compounds. This composite structure achieves both high durability and high emission efficiency, resolving the contradiction between reliability and performance.
Solution Approach 2:
The patent optimizes specific molecular parameters including the spirofluorene core structure, carbonyl group positioning, and substituent patterns to achieve optimal balance between durability and emission efficiency. By carefully controlling molecular weight, glass transition temperature, and HOMO-LUMO energy levels, the patent achieves high performance without excessive structural complexity.
2Productivity
If conventional organic electroluminescent elements use standard materials, then the material selection is simple, but the emission efficiency is insufficient
Solution Approach 1:
The patent employs composite materials combining spirofluorene backbones with carbonyl-containing aromatic rings, creating molecules that exhibit both high stability and high emission efficiency. The synergistic effect of these structural elements produces superior luminescence properties compared to simple organic compounds.
Solution Approach 2:
The patent introduces specific functional groups (carbonyl groups) at strategic positions within the spirofluorene structure to enhance emission efficiency locally, while the overall spirofluorene framework maintains structural stability. This localized functionalization achieves high productivity without requiring complete structural redesign.
3Productivity
If light-emitting materials with shorter emission wavelengths are used, then the emission efficiency improves, but the durability decreases
Solution Approach 1:
The patent uses composite structures where spirofluorene provides robust structural stability for durability, while carbonyl-containing aromatic groups enable shorter wavelength emission with high efficiency. This composite approach allows simultaneous achievement of high emission efficiency and durability that cannot be obtained with single-structure compounds.
Solution Approach 2:
The patent adjusts molecular parameters such as the type of aromatic ring (benzene, pyridine, pyrimidine), position of carbonyl groups, and substituent patterns to tune emission wavelength while maintaining durability through the stable spirofluorene core. This parameter optimization resolves the trade-off between emission efficiency and durability.
4Use of energy by moving object
If the driving voltage is reduced, then the energy consumption decreases, but the emission efficiency may be compromised
Solution Approach 1:
The patent optimizes the HOMO-LUMO energy gap and molecular energy levels of the spirofluorene-carbonyl compounds to achieve low driving voltage operation. By tuning these energy parameters, the patent enables efficient electron-hole recombination at lower voltages without sacrificing emission efficiency, thus reducing energy consumption while maintaining high productivity.
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 solution achieves a lower required driving voltage and enhances the emission efficiency and durability of the organic electroluminescent element, effectively addressing the limitations of existing technologies.
Implementation Method 1
the at least one organic layer comprises at least one of compounds represented by formula (I)... the light-emitting layer comprises at least one triplet light-emitting material... the at least one triplet light-emitting material contained in the light-emitting layer is a platinum complex or an iridium complex
Implementation Method 2
an organic electroluminescent element which comprises: a pair of electrodes; and at least one organic layer comprising a light-emitting layer between the pair of electrodes
Data Source
AI summary
An organic electroluminescent element, which comprises: a pair of electrodes; and at least one organic layer comprising a light-emitting layer between the pair of electrodes, wherein the at least one organic layer comprises at least one of compounds represented by formula (I):(R1)m-(A1)n (I)wherein R1 represents a substituent; m represents an integer of 2 or more; n represents an integer of 1 or more; and A1 represents a group selected from the group consisting of specific compounds, with the proviso that when m or n is 2 or more, a plurality of R1's or A1's may be the same or different.