Metal Complex Ligand Design for OLED Efficiency and Durability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing organic electroluminescent devices face limitations in external quantum efficiency and durability, particularly when using triplet light emitting materials, as they often have internal quantum efficiencies capped at about 25% and light extraction efficiencies at about 20%, resulting in external quantum efficiencies of around 5%.
Innovation Solution
Incorporating a metal complex with tridentate or more ligands and two or more metal ions, such as rhodium, palladium, rhenium, iridium, or platinum ions, into the organic electroluminescent device's light emitting layer, which enhances phosphorescent quantum yield and extends the lifetime of phosphorescent light emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If triplet light emitting material (phosphorescent material) is used to enhance internal quantum efficiency, then external quantum efficiency is improved, but durability deteriorates
Solution Approach 1:
The patent employs composite phosphorescent materials comprising multiple metal ions (such as Ir3+, Pt2+, Rh3+, Pd2+, or Re3+) within a single complex structure. This composite approach allows the material to achieve high external quantum efficiency through phosphorescent emission while the specific combination of metal ions and ligands provides enhanced stability and durability, resolving the contradiction between efficiency improvement and durability maintenance.
Solution Approach 2:
The patent modifies the chemical parameters of the phosphorescent material by incorporating specific metal ions (Ir3+, Pt2+, Rh3+, Pd2+, Re3+) with appropriate oxidation states and coordinating them with stable ligands. These parameter changes in metal ion selection and coordination chemistry enable the material to simultaneously achieve high quantum efficiency and improved durability compared to conventional phosphorescent materials.
2Productivity
If conventional phosphorescent material is used, then light emission is achieved, but light emission efficiency is insufficient
Solution Approach 1:
The patent changes the optical parameters of the light emitting layer by introducing phosphorescent metal complexes with specific electronic structures. These parameter changes in the material's photophysical properties enable efficient triplet state utilization and enhanced light emission efficiency, reducing energy loss and improving overall light extraction compared to conventional fluorescent materials.
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 significantly improves external quantum efficiency and durability of the organic electroluminescent device, achieving higher light emission efficiency and longer device lifespan compared to conventional devices.
Implementation Method 1
A technology, which can enhance the internal quantum efficiency of an organic electroluminescent by the use of a triplet light emitting material (phosphorescent material) including a platinum complex
Implementation Method 2
The present invention relates to an organic electroluminescent device (EL device) which can emit light by converting electric energy into optical energy
Data Source
AI summary
An organic electroluminescent device comprising: a pair of electrodes; and at least one organic compound layer including a light emitting layer between the pair of electrodes, wherein the organic compound layer contains a metal complex that has a tridentate or more ligand and two or more metal ions.