Dinuclear Metal(I) Complexes for Stable OLED Emission

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Solution Overview

Problem

Current OLED technologies face challenges with the long-term stability, thermal stability, chemical stability against water and oxygen, availability of emission colors, manufacturing reproducibility, efficiency at high current densities, and toxicity of triplet emitter materials, which affect the performance and lifespan of organic electroluminescent devices.

Innovation Solution

The use of dinuclear metal(I) complexes with tetradentate ligands, which provide thermal stability, suppress dissociation processes, and offer a wide range of emission colors, achieving high emission quantum yields and solubility in organic solvents, thereby improving the performance and lifespan of OLEDs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If triplet emitter materials are used to achieve high emission quantum yields and efficiency, then luminous efficacy is significantly improved, but long-term stability, thermal stability, and chemical stability deteriorate

Engineering Contradiction:
Improveluminous efficacyVSAvoidlong-term stability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent employs dinuclear metal(I) complexes with tetradentate ligands as composite emitter materials that combine the high luminous efficacy of triplet emitters with enhanced stability. The specific complex structure (Formula I) with copper or silver metal centers coordinated to tetradentate ligands creates a composite material system that achieves both high efficiency and improved long-term, thermal, and chemical stability compared to conventional triplet emitters.

Inventive Principle:
Principle #40Composite materials

2Quantity of substance

If conventional triplet emitter materials are used, then high emission quantum yields are achieved, but manufacturing reproducibility and service life deteriorate

Engineering Contradiction:
Improveemission quantum yieldVSAvoidmanufacturing reproducibility
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent changes the fundamental parameters of the emitter material by transitioning from conventional triplet emitters to dinuclear metal(I) complexes with specific tetradentate ligand structures. This parameter change in the molecular architecture (Formula I) with defined metal centers (Cu or Ag), ligand types (L1-L4), and stoichiometry enables improved manufacturing reproducibility while maintaining high emission quantum yields, as evidenced by the consistent performance across different embodiments.

Inventive Principle:
Principle #35Parameter changes

3Power

If triplet emitter materials are used to achieve high efficiency, then luminous performance is improved, but toxicity and environmental harm increase

Engineering Contradiction:
ImproveefficiencyVSAvoidtoxicity
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The patent employs copper and silver metal centers in the dinuclear complexes (Formula I), which are inherently less toxic and more environmentally benign compared to conventional triplet emitter materials containing heavy metals like iridium, platinum, or osmium. This substitution of metal centers maintains high luminous efficiency while significantly reducing toxicity and environmental harm, aligning with the principle of using less harmful materials.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 dinuclear metal(I) complexes enhance the service life, thermal stability, and efficiency of OLEDs, particularly in blue and green luminescent devices, while offering a wide range of emission colors and high solubility, addressing the limitations of previous triplet emitter materials.

Implementation Method 1

organometallic complexes that show phosphorescence instead of fluorescence have increasingly been used as emitting materials

Methodology Applied
Scientific EffectPhosphorescence: Phosphorescence

Data Source

PatentEP3160974B1Binuclear metal (i) complexes with tetradentate ligands for optoelectronic applications
Publication Date: 2018.08.15 CYNORA
  • EP3160974B1 patent drawingFigure 1
  • EP3160974B1 patent drawingFigure 2
  • EP3160974B1 patent drawingFigure 3

AI summary

The invention relates to metal(I) complexes of the formula A and to the use thereof in optoelectronic components, especially in OLEDs, with M = independently selected from the group consisting of Cu and Ag; X = independently selected from the group consisting of Cl, Br, I, CN, OCN, SCN, alkynyl, thiolate and N3; L = a tetradentate ligand composed of two identical or different subunits EHD joined via a spacer unit S'' and optionally S', with E = RE* (when E*= N, P, As, Sb) or E* (when E* = C*, O, S) with E* independently selected from the group consisting of N, where N is not an imine nitrogen atom or part of an N-heteroaromatic ring, P, C*, O, S, As and Sb with C*= a divalent carbene carbon atom and R = independently selected from the group consisting of hydrogen, halogen and substituents bonded directly or via oxygen atoms (-OR), nitrogen atoms (-NR2), silicon atoms (-SiR3) or sulfur atoms (-SR), and alkyl, heteroalkyl, aryl, heteroaryl, alkenyl and alkynyl groups or substituted alkyl, heteroalkyl, aryl, heteroaryl and alkenyl groups (with substituents such as halogens or deuterium, alkyl groups, heteroalkyl groups, aryl groups, heteroaryl groups); D = RD* (when D* = N, P, As, Sb) or D* (when D* = C*, O, S) with D* independently selected from the group consisting of N, where N is not an imine nitrogen atom or part of an N-heteroaromatic ring, P, C*, O, S, As and Sb with C*= a divalent carbene carbon atom and R = independently selected from the group consisting of hydrogen, halogen and substituents bonded directly or via oxygen atoms (-OR), nitrogen atoms (-NR2), silicon atoms (-SiR3) or sulfur atoms (-SR), and alkyl, heteroalkyl, aryl, heteroaryl, alkenyl and alkynyl groups or substituted alkyl, heteroalkyl, aryl, heteroaryl and alkenyl groups; where D and E are different from one another.