Ir Metal-Carbene Complexes for OLED Hole Transport
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Solution Overview
Problem
Current organic light-emitting diodes (OLEDs) face challenges in achieving stability, long lifetime, and high quantum efficiency, particularly in the blue region of the electromagnetic spectrum, with existing materials not adequately addressing these requirements.
Innovation Solution
The use of Ir metal-carbene complexes with one, two, or three bidentate azabenzimidazole carbene ligands as hole-transport or electron/exciton blocker materials in OLEDs, specifically in the hole transport layer or electron/exciton blocking layer, to enhance stability and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional hole-transport materials and electron/exciton blocker materials are used in OLEDs, then the device structure is simple and manufacturing is easier, but the quantum efficiency and operational lifetime are insufficient
Solution Approach 1:
The patent changes the chemical and physical parameters of the hole-transport and electron/exciton blocker materials by introducing Ir metal-carbene complexes with specific bidentate azabenzimidazole carbene ligands. These parameter changes in molecular structure, electronic properties, and coordination chemistry enable simultaneously improved quantum efficiency and operational lifetime while maintaining reasonable device complexity
Solution Approach 2:
The patent employs composite material strategy by combining Ir metal centers with bidentate azabenzimidazole carbene ligands to create complex materials that exhibit synergistic properties. These composite materials provide both the hole-transport and electron/exciton blocking functions with enhanced stability and efficiency, resolving the contradiction between performance improvement and material complexity
2Use of energy by moving object
If phosphorescent emitters are used to improve quantum efficiency, then up to four times higher efficiency is achieved, but the stability and lifetime in the blue region remain insufficient
Solution Approach 1:
The patent changes the emitter material parameters by using Ir metal-carbene complexes with bidentate azabenzimidazole carbene ligands, which possess unique electronic structures and triplet energy levels. These parameter changes enable high quantum efficiency through phosphorescence while achieving improved stability and lifetime in the blue emission region
Solution Approach 2:
The Ir metal-carbene complexes act as intermediary materials between the electron transport and hole transport layers, facilitating efficient charge recombination and exciton formation while maintaining high stability. These intermediary materials enable the realization of high quantum efficiency without sacrificing blue region stability
3Productivity
If existing hole-transport and electron/exciton blocker materials are used, then the device structure is maintained, but high operational voltage and reduced efficiency are observed
Solution Approach 1:
The patent changes the energy level parameters and charge transport properties by introducing Ir metal-carbene complexes with specific bidentate azabenzimidazole carbene ligands. These parameter changes optimize the energy alignment between layers, reduce operational voltage, and improve overall operational efficiency
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 metal-carbene complexes improve the stability and quantum efficiency of OLEDs, particularly in the blue region, enabling the production of full-color displays and white OLEDs with extended operational lifetimes and reduced operational voltage.
Implementation Method 1
hole-transport material and/or at least one electron/exciton blocker material is an Ir metal-carbene complex
Implementation Method 2
The phosphorescent emitters are typically organometallic complexes which, in contrast to the fluorescence emitters which exhibit singlet emission, exhibit triplet emission
Implementation Method 3
OLEDs exploit the propensity of materials to emit light when they are excited by electrical current
Data Source
AI summary
An organic electronic device comprising at least one hole-transport material and/or at least one electron/exciton blocker material, wherein said at least one hole-transport material and/or said at least one electron/exciton blocker material is an Ir metal-carbene complex comprising one, two or three specific bidentate azabenzimidazole ligands; a hole transport layer or an electron/exciton blocking layer, comprising at least one Ir metal-carbene complex, comprising one, two or three specific bidentate azabenzimidazole ligands; an apparatus selected from the group consisting of stationary visual display units, mobile visual display units, illumination units, units in items of clothing, units in furniture and units in wallpaper, comprising the organic electronic device of the present invention or the hole transport layer or the electron/exciton blocking layer of the present invention; and the use of an Ir metal-carbene complex comprising one, two or three specific bidentate azabenzimidazole ligands according to the present invention as hole-transport material and/or electron/exciton blocker material.