Platinum(II) ONNO Complex Anti-Aggregation for Deep Red OLEDs
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Solution Overview
Problem
Current deep red light-emitting platinum(II) complexes face challenges with self-aggregation at high doping concentrations, leading to excimer formation, reduced color purity, and device instability, limiting their industrial application.
Innovation Solution
A platinum(II) tetradentate ONCN complex with a specific chemical structure is developed, featuring strong anti-aggregation properties and high emission quantum efficiency, even at high doping concentrations, allowing for the production of high-efficiency OLEDs with pure deep red light emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the doping concentration of platinum(II) complex is increased to improve device efficiency, then external quantum efficiency is improved, but self-aggregation and excimer formation occur leading to reduced color purity
Solution Approach 1:
The patent introduces different substituents at specific positions of the bipyridine diphenol ligand to create local steric hindrance and electronic effects. The substituents are strategically placed to prevent self-aggregation at high doping concentrations while maintaining the planar geometry needed for efficient emission, thus resolving the contradiction between efficiency and color purity
Solution Approach 2:
The patent employs asymmetric substitution patterns on the bipyridine diphenol ligand, where different groups are placed at different positions to break the symmetry. This asymmetric structure prevents molecular stacking and excimer formation while preserving the overall planar configuration, enabling high efficiency emission with maintained color purity at elevated doping concentrations
2Power
If the doping concentration is increased to improve device efficiency, then external quantum efficiency is improved, but device stability deteriorates due to excimer formation
Solution Approach 1:
The patent introduces different substituents at specific positions of the bipyridine diphenol ligand to create local steric hindrance and electronic effects. The substituents are strategically placed to prevent self-aggregation at high doping concentrations while maintaining the planar geometry needed for efficient emission, thus resolving the contradiction between efficiency and color purity
Solution Approach 2:
The patent incorporates bulky substituents and electron-donating groups in advance to prevent self-aggregation and excimer formation before they can occur during device operation. These pre-installed protective groups maintain molecular spacing and prevent the formation of unstable excimer structures, ensuring device stability at high doping concentrations
3Power
If electron donor groups are introduced to enhance carrier injection/transport, then external quantum efficiency is improved, but molecular aggregation is enhanced leading to excimer formation
Solution Approach 1:
The patent introduces different substituents at specific positions of the bipyridine diphenol ligand to create local steric hindrance and electronic effects. The substituents are strategically placed to prevent self-aggregation at high doping concentrations while maintaining the planar geometry needed for efficient emission, thus resolving the contradiction between efficiency and color purity
Solution Approach 2:
The patent combines electron-donating groups with bulky sterically hindering substituents to create a composite molecular structure. This composite approach provides both enhanced carrier injection/transport capability and protection against molecular aggregation, resolving the contradiction between improving efficiency and preventing excimer formation
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 platinum(II) tetradentate ONCN complex maintains high external quantum efficiency and color purity across a wide range of doping concentrations, effectively addressing the issues of self-aggregation and excimer formation, making it suitable for industrial manufacturing.
Implementation Method 1
The strong spin-orbit coupling of heavy metal atoms can effectively promote the inter-system crossing (ISC) of electrons from singlet to triplet
Implementation Method 2
Professor Forrest of the Princeton University and Professor Thompson of the University of Southern California discovered the phosphorescent electroluminescence of metal organic complex molecular materials at room temperature
Implementation Method 3
Professor Forrest of the Princeton University and Professor Thompson of the University of Southern California discovered the phosphorescent electroluminescence of metal organic complex molecular materials at room temperature
Data Source
AI summary
The invention relates to a platinum (ii) tetradentate onno complex luminescent material, preparation method and application thereof in organic light emitting diode. A platinum (II) tetradentate pyridine diphenol ONNO complex light-emitting material having the chemical structure of Formula (I) can be used for manufacturing organic light-emitting diodes emitting pure red light. The light-emitting material of the invention, because the end of the left side thereof is connected to benzofuran, has more red shift than the emission spectrum of the bipyridyl phenol ONNO-Pt(II) complex without a benzofuran group, and the anti-aggregation performance of the platinum(II) complex is effectively increased, as a B group is introduced on the phenolic ring on the right side thereof, so the self-quenching rate constant is low, and the color purity emitting deep red light and better luminous efficiency can be maintained in a certain range of doping concentration, which is more suitable for industrial preparation systems.