Hexadentate Organometallic Compound for OLED Stability

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Solution Overview

Problem

Organic light-emitting devices face challenges in maintaining stability and efficiency due to the transition of triplet excitons to non-luminescent states, leading to reduced lifespan and performance.

Innovation Solution

An organometallic compound with a hexadentate ligand bonded to a metal atom, where the energy level of the triplet metal-centered state is higher than the triplet metal-to-ligand charge transfer state, is used in the organic light-emitting device, reducing the transition probability to the non-luminescent state and enhancing stability and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional organometallic compounds are used in organic light-emitting devices, then device operation is achieved, but triplet excitons transition to non-luminescent 3MC states reducing efficiency and lifespan

Engineering Contradiction:

Improvedevice efficiencyVSAvoiddevice lifespan

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent changes the energy level parameters of the organometallic compound by designing a specific hexadentate ligand structure where the 3MC state energy level is higher than the 3MLCT state energy level. This parameter change prevents the harmful transition of triplet excitons to non-luminescent states, thereby improving both device efficiency and lifespan simultaneously

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite organometallic compound consisting of a metal atom (M1) coordinated with a specifically designed hexadentate ligand containing multiple heterocyclic groups. This composite structure achieves the desired energy level configuration that prevents exciton transition to non-luminescent states

Inventive Principle:

Principle #40Composite 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 use of this organometallic compound in the organic light-emitting device improves stability in the excited state, leading to enhanced efficiency and lifespan by preventing triplet exciton transitions to non-luminescent states, resulting in improved performance.

Implementation Method 1

an energy level (E3MC) of a 3MC state (triplet metal centered state) of the organometallic compound is higher than an energy level (E3MLCT) of a 3MLCT state (triplet metal-to-ligand charge transfer state) of the organometallic compound

Methodology Applied

Scientific EffectMetal-to-ligand charge transfer (MLCT):

Implementation Method 2

Carriers, such as holes and electrons, recombine in the emission layer to produce excitons. These excitons transit from an excited state to a ground state, thereby generating light.

Methodology Applied

Scientific EffectPhosphorescence: Phosphorescence

Data Source

PatentUS11667659B2Organometallic compound and organic light-emitting device including the same

Publication Date: 2023.06.06 SAMSUNG DISPLAY CO LTD

AI summary

An organometallic compound includes a hexadentate ligand bonded to a metal atom (M1). An energy level (E3MC) of a 3MC state (triplet metal centered state) of the organometallic compound is higher than an energy level (E3MLCT) of a 3MLCT state (triplet metal-to-ligand charge transfer state) of the organometallic compound.