Iridium Platinum Carbene Complexes for OLED Stability

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Solution Overview

Problem

Current iridium and platinum carbene complexes used in OLEDs lack stability and efficiency, limiting their industrial application and performance in producing full-color displays and white OLEDs with high color rendering index and long lifetime.

Innovation Solution

Development of iridium and platinum complexes with monoanionic bidentate carbene ligands, specifically designed for use as emitters, charge transport materials, or exciton blockers in OLEDs, offering improved efficiency, color tuning capabilities, and stability through a broad emission spectrum.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If existing carbene complexes are used, then OLED operation is achieved, but color-tuning capability and emission spectrum breadth are limited

Engineering Contradiction:

Improvecolor-tuning capabilityVSAvoidemission spectrum breadth

Core Design Contradiction:

Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The patent introduces different donor and acceptor groups at specific positions of the carbene ligand structure. This creates local variations in electron density and HOMO-LUMO energy levels, enabling precise color-tuning of the emission spectrum while maintaining broad overall emission characteristics

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

By systematically varying the substituent parameters on the carbene ligand (electron-donating or electron-withdrawing groups), the patent tunes the photophysical parameters of the complex, achieving both color-tuning capability and broad emission spectrum suitable for full-color displays and white OLEDs

Inventive Principle:

Principle #35Parameter changes

2Duration of action of stationary object

If current metal carbene complexes are applied, then OLED function is achieved, but lifetime and operational duration are insufficient

Engineering Contradiction:

Improveoperational lifetimeVSAvoidstability

Core Design Contradiction:

Duration of action of stationary objectVSReliability

Solution Approach 1:

The patent designs carbene ligands with steric bulk and protective substituents that beforehand cushion the metal center from degradation pathways. This protective structural design prevents premature decomposition and extends the operational lifetime of the OLED device

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The combination of robust metal centers (Ir or Pt) with stable bidentate carbene ligands creates a composite material with enhanced thermodynamic and kinetic stability. This composite structure resists degradation under operational conditions, extending device lifetime

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 complexes provide enhanced electroluminescence properties, enabling the production of high-efficiency, long-lasting, and color-tunable OLEDs suitable for full-color displays and white lighting applications.

Implementation Method 1

Organic light-emitting diodes (OLEDs) exploit the propensity of materials to emit light when they are excited by electrical current

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS10128448B2Transition metal complexes with carbene ligands and the use thereof in OLEDs

Publication Date: 2018.11.13 UDC IRELAND

AI summary

The present invention relates to iridium and platinum carbene complexes of the general formula (I), to OLEDs (Organic Light-Emitting Diodes) which comprise such complexes, to a device selected from the group consisting of illuminating elements, stationary visual display units and mobile visual display units comprising such an OLED, to the use of such a metal-carbene complex in OLEDs, for example as emitter, matrix material, charge transport material and/or charge or exciton blocker.