Dimeric Phosphorescent Compound for OLED Color Purity
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Solution Overview
Problem
Current phosphorescent materials for organic electroluminescence devices have limitations in luminous efficiency and color purity, particularly for red and green light emission, with existing compounds like (4,6-F2ppy)2Irpic emitting light in the sky blue region and having large shoulder peaks that affect color purity.
Innovation Solution
A phosphor dimeric metallic compound with a new co-ligand structure, specifically a transition metal compound represented by Chemical Formula 1, where M is Ir, Pt, Rh, Re, or Os, forming a complex with a carboxyl substituent and a heteroaromatic dicarboxylic acid derivative as a co-ligand, which enhances luminous efficiency and color purity by controlling light emission and wavelength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional phosphorescent materials like (4,6-F2ppy)2Irpic are used, then blue light emission is achieved, but color purity deteriorates due to large shoulder peaks and sky blue region emission
Solution Approach 1:
The patent changes the chemical structure parameters of the phosphorescent material by introducing a dimeric structure with specific co-ligands (Formula 1). This structural parameter change modifies the emission characteristics, achieving narrow emission peaks and high color purity while maintaining efficient light emission in the blue region.
Solution Approach 2:
The invention creates a composite phosphorescent material combining a dimeric metal complex core with specifically designed co-ligands. This composite structure integrates the advantages of both the metal complex (efficient triplet exciton utilization) and the co-ligand system (narrow emission, high color purity), resolving the contradiction between emission intensity and color purity.
2Productivity
If high doping concentrations are used to improve luminous efficiency, then more light is emitted, but concentration quenching increases and reduces efficiency
Solution Approach 1:
The patent segments the phosphorescent material into a dimeric structure where two metal complex units are connected through co-ligands. This segmentation creates a structure that maintains efficient triplet exciton utilization while reducing concentration quenching effects, allowing high luminous efficiency even at optimized doping concentrations.
Solution Approach 2:
The co-ligands in the dimeric structure act as intermediaries between the metal complex units. These intermediaries facilitate energy transfer and maintain structural stability, preventing concentration quenching while preserving high luminous efficiency. The co-ligands mediate the interaction between excitons and the surrounding matrix.
3Use of energy by moving object
If conventional phosphorescent materials are used, then triplet excitons are utilized, but lifespan is limited compared to fluorescent materials
Solution Approach 1:
The patent changes the chemical composition parameters by incorporating specific co-ligands with electron-donating or electron-withdrawing groups (Formula 1). These parameter changes modify the electronic structure and stability of the phosphorescent material, extending its operational lifespan while maintaining efficient triplet exciton utilization for phosphorescent emission.
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 new compound increases the lifespan and luminous efficiency of light-emitting materials, reduces concentration quenching, and maintains high efficiency even at high doping concentrations, leading to improved performance in organic electroluminescence devices and various display applications.
Implementation Method 1
Phosphorescent materials generally include organic/inorganic compound structures including transition element atoms. The transition element atoms change triplet excitons, which used to be impossible to transition, into excitons that are possible to transition, causing them to emit phosphorescent light.
Data Source
AI summary
The present invention relates to an organic electroluminescence device containing a light emitting metallic compound of Chemical Formula 1.In the Chemical Formula 1, M is selected from Ir, Pt, Rh, Re, and Os, and m is 2, provided that m is 1 when M is Pt.