Ir-Pt Dinuclear Complexes for Stable Blue PHOLED Emission

Solution Overview

Problem

Platinum complexes in organic light-emitting diodes (OLEDs) have deeper HOMO and LUMO levels, making them ineffective charge trappers and leading to charge leakage and low efficiency, while iridium complexes are efficient but lack stability, especially for blue color emission.

Innovation Solution

Development of dinuclear or multinuclear iridium-platinum complexes with a tetradentate ligand structure, combining the charge trapping property of iridium and the stability of platinum, used as emitters in phosphorescent OLEDs (PHOLEDs) to achieve efficient blue light emission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If platinum complexes are used in OLEDs, then stability is improved, but charge trapping efficiency deteriorates due to deeper HOMO and LUMO levels

Engineering Contradiction:

Improvecomplex stabilityVSAvoidcharge trapping efficiency

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The patent combines iridium and platinum metals into a single dinuclear complex, merging the charge trapping capability of iridium with the stability of platinum. The complex contains both Ir and Pt atoms coordinated with organic ligands, creating a hybrid structure that exhibits properties of both parent metals.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The invention creates a composite metal complex material that integrates two different metals (Ir and Pt) with organic ligands. This composite structure allows the material to simultaneously achieve the charge trapping efficiency characteristic of iridium complexes and the stability characteristic of platinum complexes.

Inventive Principle:

Principle #40Composite materials

2Reliability

If iridium complexes are used in OLEDs, then charge trapping efficiency is improved, but stability deteriorates especially for blue color emission

Engineering Contradiction:

Improvecharge trapping efficiencyVSAvoidcomplex stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent combines iridium and platinum metals into a single dinuclear complex, merging the charge trapping capability of iridium with the stability of platinum. The complex contains both Ir and Pt atoms coordinated with organic ligands, creating a hybrid structure that exhibits properties of both parent metals.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The invention creates a composite metal complex material that integrates two different metals (Ir and Pt) with organic ligands. This composite structure allows the material to simultaneously achieve the charge trapping efficiency characteristic of iridium complexes and the stability characteristic of platinum complexes.

Inventive Principle:

Principle #40Composite materials

3Ease of manufacture

If conventional OLED materials are used, then manufacturing cost is reduced, but performance and efficiency deteriorate

Engineering Contradiction:

Improvemanufacturing costVSAvoiddevice efficiency

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The patent modifies the molecular structure parameters of the emissive material by creating dinuclear Ir-Pt complexes with specific ligand configurations. These parameter changes in the molecular structure lead to improved device efficiency while maintaining compatibility with existing OLED manufacturing processes.

Inventive Principle:

Principle #35Parameter changes

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 Ir/Pt complexes exhibit improved stability and efficiency, enhancing the internal quantum efficiency and achieving stable blue light emission with a peak wavelength between 400 nm to 480 nm, overcoming the limitations of individual iridium and platinum complexes.

Implementation Method 1

Development of dinuclear or multinuclear iridium-platinum complexes with a tetradentate ligand structure, combining the charge trapping property of iridium and the stability of platinum, used as emitters in phosphorescent OLEDs (PHOLEDs) to achieve efficient blue light emission.

Methodology Applied

Scientific EffectPhosphorescence: Phosphorescence

Data Source

PatentUS9735378B2Organic electroluminescent materials and devices

Publication Date: 2017.08.15 UNIVERSAL DISPLAY CORP

AI summary

Ir/Pt metal complexes, devices containing the Ir/Pt metal complexes, and methods of making such devices are described. The Ir/Pt metal complex includes a first Ir moiety and a first Pt moiety. The first Ir moiety can be an Ir(III) six-coordinated structure. The first Pt moiety can be a Pt(II) four-coordinated tetradentate structure. The devices can have layers that include the Ir/Pt metal complexes. The layers containing the Ir/Pt metal complexes can be made by a solution process.