OLED Emitter Metal Complexes for Lifetime and Emission Control

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Solution Overview

Problem

Current organic light-emitting diode (OLED) technologies face limitations in achieving optimal performance, particularly in device efficiency, emission peak line shape, and device lifetime when using conventional emitter materials.

Innovation Solution

The development of specific metal complexes as emitter dopants in OLEDs, which include a ligand complexed to a metal to form a 5-membered chelate ring, enhancing the performance by improving the efficiency and emission characteristics of OLEDs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional emitter materials are used in OLEDs, then the device structure and materials are simpler and more conventional, but the device efficiency, emission peak line shape, and device lifetime are suboptimal

Engineering Contradiction:

Improvedevice lifetimeVSAvoidemitter material structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent modifies the chemical structure of emitter materials by introducing specific ligand complexes with metals to form 5-membered chelate rings. This structural parameter change in the emitter material leads to improved device lifetime, efficiency, and emission characteristics without fundamentally changing the OLED device architecture

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite emitter materials consisting of metal complexes coordinated with specific ligands (such as cyclometalating ligands and ancillary ligands). These composite materials combine the properties of different chemical components to achieve superior device performance including extended lifetime and improved efficiency

Inventive Principle:

Principle #40Composite materials

2Productivity

If conventional emitter materials are used in OLEDs, then the material selection and fabrication are simpler, but the device efficiency and emission characteristics are suboptimal

Engineering Contradiction:

Improvedevice efficiencyVSAvoidemitter dopant structure

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent optimizes emitter efficiency by changing the chemical parameters of the dopant materials, specifically using metal complexes with 5-membered chelate rings formed by ligands. This parameter change in the molecular structure enhances the efficiency of electroluminescence while maintaining manageable fabrication complexity

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The metal complex acts as an intermediary between the electrical input and light output in the OLED. The specific ligand-metal-chelate ring structure serves as an efficient mediator that facilitates electron-hole recombination and energy transfer, thereby improving device efficiency

Inventive Principle:

Principle #24Intermediary (Mediator)

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 these metal complexes as emitter dopants in OLEDs leads to improved device efficiency, emission peak line shape, and extended device lifetime, addressing the limitations of conventional materials.

Implementation Method 1

OLEDs make use of thin organic films that emit light when voltage is applied across the device

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS11839141B2Organic electroluminescent materials and devices

Publication Date: 2023.12.05 UNIVERSAL DISPLAY CORP

AI summary

A novel compound having a first ligand LA ofis disclosed. The compound is useful as emitter dopant in OLEDs.