Organometallic OLED Emitters for Saturated Color and Stable Emission
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Solution Overview
Problem
Conventional OLEDs face challenges in achieving saturated red, green, and blue pixel emissions required for full color displays, and there is a need for improved organic materials that can efficiently emit light with high efficiency and stability.
Innovation Solution
The development of organometallic compounds with specific ligand structures coordinated to metals like Os, Ir, Pd, Pt, Cu, Ag, or Au, which are incorporated into OLEDs to enhance light emission properties, allowing for the formation of tridentate, tetradentate, pentadentate, or hexadentate ligands, and can be used in formulations to improve the performance of organic light-emitting diodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional organic materials are used in OLEDs, then the device structure can be relatively simple and manufacturing can be easier, but the light emission efficiency and color saturation are insufficient
Solution Approach 1:
The patent modifies the molecular structure parameters of organic materials by introducing specific ligand structures (Formula I) with varying denticity (tridentate, tetradentate, pentadentate, or hexadentate) and substituent groups (R1, RA) to optimize light emission efficiency and color saturation while maintaining compatibility with existing OLED device architectures
Solution Approach 2:
The patent develops composite organometallic compounds combining organic ligands (Formula I) with metal centers (M = Os, Ir, Pd, Pt, Cu, Ag, or Au) to create materials that exhibit enhanced photoluminescence and electroluminescence properties, achieving saturated red, green, and blue emissions required for full color displays
2Reliability
If conventional organic materials are used in OLEDs, then material cost can be lower, but the stability and durability of light emission are insufficient
Solution Approach 1:
The patent optimizes the chemical composition parameters of organometallic compounds by selecting specific metal centers (Ir, Pt, Os) known for their photostability and incorporating stable ligand frameworks (Formula I) with various substituent groups to enhance the thermal and photochemical stability of the emissive materials, thereby improving OLED device lifetime
Solution Approach 2:
The patent explores cost-effective organometallic compounds using relatively abundant metals (Cu, Ag, Au) alongside precious metals, and employs solution-processable ligand structures that can be deposited using low-cost fabrication techniques, aiming to reduce material costs while maintaining emission stability
3Illumination intensity
If white OLED with absorption filters is used, then device structure can be simpler, but the color saturation and emission efficiency are reduced
Solution Approach 1:
The patent designs emissive materials with specific ligand structures (Formula I) that emit saturated red, green, and blue light at distinct wavelengths, allowing individual pixels to be optimized for specific color emissions without requiring broad-spectrum white emission and subsequent filtering, thereby achieving high color saturation directly at the emitter level
Solution Approach 2:
The patent tunes the emission wavelength and color properties by modifying the ligand structure parameters in Formula I, including the choice of moiety A (monocyclic or polycyclic ring structures), substituent groups (R1, RA), and denticity, to achieve precise control over the emission spectrum for saturated color display applications
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
These compounds enhance the efficiency and stability of OLEDs, enabling the production of saturated colors and improving the overall performance of organic light-emitting devices.
Implementation Method 1
OLEDs make use of thin organic films that emit light when voltage is applied across the device
Implementation Method 2
One application for phosphorescent emissive molecules is a full color display
Data Source
AI summary
A compound including a first ligand LA of Formula I,is disclosed. In Formula I, moiety A is a monocyclic or polycyclic ring structure comprising 5-membered and/or 6-membered rings; each R1 and RA is independently hydrogen or a general substituent; LA is coordinated to a metal M, selected from the group consisting of Os, Ir Pd, Pt, Cu, Ag, and Au; metal M can be coordinated to other ligands; and any two of R1 and RA can be joined or fused together to form a ring. Formulations, OLEDs, and consumer products containing the compound, as well as, methods of making the compound are also disclosed.