Iridium OLED Emitters With Polycyclic Ligands for Saturated Color
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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 produce white light for use in displays, illumination, and backlighting.
Innovation Solution
The development of a compound of Formula Ir(LA)x(LB)y(LC)z, where LA, LB, and LC are specific ligands, forming a polycyclic fused ring system, which can be used in an OLED to enhance light emission properties, including the production of saturated colors and white light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional organic materials are used in OLEDs, then the devices can be fabricated with cost advantages and flexibility, but the color saturation and emission quality required for full color displays cannot be achieved
Solution Approach 1:
The patent modifies the molecular structure parameters of organic emitters by introducing specific ligand combinations (LA, LB, LC) with defined coordination geometries to the iridium center, thereby tuning the photophysical properties to achieve saturated red, green, and blue emissions while maintaining the benefits of organic materials
Solution Approach 2:
The invention employs composite ligand systems where LA, LB, and LC work synergistically in coordination to the iridium metal center, creating a composite molecular structure that combines the advantages of different ligand types to achieve both color saturation and manufacturing feasibility
2Illumination intensity
If white light emission is achieved using conventional organic materials, then the materials can be used for illumination and backlighting, but the efficiency and color quality do not meet industry standards
Solution Approach 1:
The patent adjusts the photophysical parameters of the iridium complex by selecting specific ligand combinations that optimize both the spectral output for white light and the radiative efficiency, achieving industry-standard performance for illumination applications
Solution Approach 2:
The invention assigns different functional roles to different ligands in the coordination sphere: LA ligands are optimized for certain emission characteristics while LB and LC ligands contribute differently, with each ligand type performing its specialized function to collectively achieve high-quality white light 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 compound enables the production of OLEDs with improved color saturation and efficiency, meeting industry standards for full color displays and providing enhanced performance in lighting applications.
Implementation Method 1
OLEDs make use of thin organic films that emit light when voltage is applied across the device
Data Source
AI summary
A compound of Formula Ir(LA)x(LB)y(LC)z is provided where x and y are independently 1 or 2; z is 0 or 1; and x+y+z=3; first ligand LA includes a structure of Formula I,ligand LB includes a structure of Formula II:and ligand LC is a bidentate ligand. In the compounds, moiety B is a polycyclic fused ring system comprising at least four rings; each of moiety C and moiety D is a monocyclic ring or a polycyclic fused ring system; each of X1 to X4 and Z1 to Z6 is C or N; L0 is a direct bond or a linking group; YA is a linking group; each substituent is hydrogen or a General Substituent defined herein; and any two substituents may be joined or fused to form a ring. Formulations, OLEDs, and consumer products containing the compound are also provided.