Tailored Organometallic OLED Materials for Saturated Color Emission

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing organic light-emitting diodes (OLEDs) face challenges in achieving saturated red, green, and blue pixel emissions required for full color displays, and conventional methods for white light emission often rely on absorption filters, which may not be efficient.

Innovation Solution

The development of organometallic compounds, specifically those following Formula I, which can be used in OLEDs to enhance light emission properties, including the use of compounds with specific substituents and ligands to improve color purity and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If conventional methods using absorption filters are used for white light emission in OLEDs, then color separation can be achieved, but light emission efficiency is reduced

Engineering Contradiction:
Improvecolor saturationVSAvoidlight emission efficiency
Core Design Contradiction:
Illumination intensityVSLoss of energy

Solution Approach 1:

The patent changes the chemical and optical parameters of the emissive materials by introducing specific organometallic compounds with tailored ligand structures (Formula I) to achieve saturated color emission directly from the emitter, eliminating the need for absorption filters and thereby preventing energy loss.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite organometallic compounds combining specific metal centers (Pd or Pt) with customized organic ligands containing heteroatoms (O, S, Se, N) to create materials that inherently emit saturated colors with high efficiency, resolving the contradiction between color saturation and emission efficiency.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If standard organometallic compounds are used in OLEDs, then device fabrication is simplified, but color purity and emission efficiency are insufficient

Engineering Contradiction:
Improvedevice fabricationVSAvoidcolor purity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies local quality by introducing specific functional groups and heteroatoms (O, S, Se, N) at particular positions within the ligand structure (Formula I), which locally enhance the optical properties and color purity of the emitter while maintaining overall molecular simplicity for ease of fabrication.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent modifies molecular parameters such as ligand composition, metal center selection, and substituent patterns in Formula I to precisely control emission wavelength and color purity, achieving high-performance emitters that remain compatible with standard OLED fabrication 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 organometallic compounds enhance the ability of OLEDs to produce saturated colors and improve light emission efficiency, addressing the limitations of conventional OLED technologies.

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

Implementation Method 2

One application for phosphorescent emissive molecules is a full color display

Methodology Applied
Scientific EffectPhosphorescence: Phosphorescence

Data Source

PatentEP4212539B1Organic electroluminescent materials and devices
Publication Date: 2025.08.06 UNIVERSAL DISPLAY CORP
  • EP4212539B1 patent drawingFigure 1
  • EP4212539B1 patent drawingFigure 2
  • EP4212539B1 patent drawing

AI summary

Compounds of Formula I, are provided. In Formula I, M is Pd or Pt; each of X1 to X14 is C or N; one of Z1 and Z2 is C and the other is N; Y is selected from O, S, Se, N∗R, CRR', SiRR', or GeRR'; K1 is a direct bond, O, or S; each R, R', RA, RB, RC, and RD is independently hydrogen or a substituent; at least one of R, R', RA, RB, RC, or RD is a substituent R∗; and (i) R∗ comprises a 5-membered or 6-membered heterocyclic ring, or (ii) R∗ comprises Formula Ia: wherein each of RY and RZ independently represents mono to the maximum allowable substitution, or no substitution; R1, R2, R3, R4, RY and RZ is independently hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, boryl, selenyl, and combinations thereof; wherein at least one of R1, R2, R3, and R4 is not hydrogen. Formulations, OLEDs, and consumer products including the compound are also provided.