Copper(I) Complexes for OLED Emitters with Low Toxicity
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Solution Overview
Problem
Current OLED technologies face limitations in achieving high efficiency and cost-effectiveness due to the use of expensive and toxic metals like Re, Os, Ir, and Pt in emitter materials, and require materials with improved solubility and emission properties for optoelectronic components.
Innovation Solution
Copper(I) complexes of the form Cu4X*4(E∩N*)2, where X*=Cl, Br, I, CN, SCN, E=R2As, R2P, and N*=bidentate ligands with an imine function, are developed, offering low toxicity, high emission quantum yield, and adjustable solubility, allowing for wide emission color range and short emission decay times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If expensive and toxic metals like Re, Os, Ir, and Pt are used in emitter materials, then high emission quantum yield and device efficiency are achieved, but production cost increases and environmental harm worsens
Solution Approach 1:
The patent replaces expensive and toxic metals (Re, Os, Ir, Pt) with copper(I), which is abundant, inexpensive, and environmentally friendly. The copper(I) complexes maintain high emission quantum yield (>50%) and short emission decay times, achieving the desired performance without relying on rare and toxic metals.
Solution Approach 2:
The patent modifies the chemical composition parameters by using copper(I) with specific ligands (phosphines, N-heterocyclic carbenes, etc.) to achieve the desired emission properties. By adjusting ligand types and substituents, the emission color, quantum yield, and decay time are optimized while maintaining low cost and low toxicity.
2Illumination intensity
If high emitter concentrations are used to improve device performance, then light output increases, but quenching effects occur that reduce emission efficiency
Solution Approach 1:
The copper(I) complexes exhibit short emission decay times, which prevents accumulation of excited states and reduces quenching effects even at high emitter concentrations. This allows the use of high concentrations to maintain or enhance light output without significant loss of emission efficiency.
3Reliability
If organometallic complexes are used to achieve high emission quantum yield, then device efficiency improves, but material complexity and difficulty of manufacture increase
Solution Approach 1:
The patent uses copper(I) salts combined with various ligands to create complexes with tailored properties. The synthesis methodology is simplified by using readily available copper(I) sources and ligands, avoiding complex multi-step syntheses required for some other organometallic emitters, while maintaining high device efficiency.
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 copper(I) complexes provide high emission quantum yield (>50%), short emission decay times, and are usable in high emitter concentrations without quenching effects, making them suitable for various optoelectronic components with reduced production costs and improved performance.
Implementation Method 1
These materials are often called triplet emitters or phosphorescent emitters
Data Source
AI summary
The invention relates to copper(I) complexes of the formula A,in whichX*═Cl, Br, I, CN and/or SCN (i.e. independently of one another);N*∩E=a bidentate ligand whereE=phosphanyl/arsenyl group of the R2E form (where R=alkyl, aryl, alkoxyl, phenoxyl, or amide);N*=imine function, which is part of a N-heteroaromatic 5- or 6-membered ring, which is chosen from the group consisting of oxazole, imidazole, thiazole, isoxazole, isothiazole, pyrazole, 1,2,3-triazole, 1,2,3-oxadiazole, 1,2,5-oxadiazole, 1,2,3-thiadiazole and 1,2,5-thiadiazole, pyridine, pyrimidine, triazine, pyrazine and pyridazine; and“∩”=at least one carbon atom, which is likewise part of the aromatic group, wherein the carbon atom is directly adjacent to both the imine nitrogen atom and to the phosphorous or arsenic atom.