Organometallic Emitters With Low Buried Volume for Fast OLED Response
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light-emitting devices, particularly self-emissive devices, face challenges in achieving optimal performance in terms of viewing angle, contrast ratio, response time, luminance, and driving voltage, which are not adequately addressed by current technologies.
Innovation Solution
Incorporation of an organometallic compound represented by Formula 1, which includes specific metal elements and substituents, into the emission layer of a light-emitting device, ensuring a triplet excited state energy greater than the binding energy and a buried volume of less than 25%, to enhance the device's performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional emission materials are used in the emission layer, then the device structure is simple, but the viewing angle, contrast ratio, and response time are insufficient
Solution Approach 1:
The patent introduces specific parameter constraints for the organometallic compound: triplet excited state energy greater than binding energy (ΔG(T1) > ΔG(BDE)) and buried volume less than 25%. These parameter changes enable the emission layer to achieve wide viewing angles and high contrast ratios while maintaining device simplicity.
Solution Approach 2:
The patent employs an organometallic compound with specific structural features (Formula 1) combining metal centers (Pt, Pd, Ir, etc.) with organic ligands containing nitrogen atoms. This composite material structure provides both the simplicity of organic materials and the superior electroluminescence performance of metal complexes, resolving the contradiction between manufacturing ease and display performance.
2Ease of manufacture
If existing emission materials are used, then the device is easy to manufacture, but the response time and luminance are inadequate
Solution Approach 1:
The patent specifies that the organometallic compound must have triplet excited state energy greater than binding energy and buried volume less than 25%. These parameter changes optimize the emission characteristics, enabling fast response times and high luminance while maintaining ease of manufacture through conventional deposition techniques.
Solution Approach 2:
The organometallic compound's optimized energy levels and small buried volume enable rapid exciton recombination and light emission, allowing the device to achieve fast response times. This 'skipping' through the emission process efficiently converts electrical energy to light, improving productivity without complicating manufacturing.
3Quantity of substance
If the triplet excited state energy is not greater than the binding energy, then the molecular packing may be denser, but the energy efficiency and emission performance deteriorate
Solution Approach 1:
The patent establishes a critical parameter relationship: triplet excited state energy must be greater than binding energy (ΔG(T1) > ΔG(BDE)). This parameter change ensures that excitons remain localized on individual molecules rather than forming aggregates, maintaining high energy efficiency and bright emission even with moderate packing densities.
Solution Approach 2:
The patent converts the potential harm of molecular aggregation (which would reduce energy efficiency) into a benefit by carefully designing the organometallic compound's energy levels. The triplet excited state energy is engineered to be higher than the binding energy, so that even when molecules pack closely, the excitons remain confined to individual emitters, turning the packing density issue into an opportunity for efficient energy use.
4Stability of the object's composition
If the buried volume of the organometallic compound is large, then the molecular packing may be more stable, but the response time and emission efficiency are reduced
Solution Approach 1:
The patent specifies that the buried volume of the organometallic compound must be less than 25% of the total volume. This parameter change creates sufficient free volume around each molecule, allowing rapid exciton migration and recombination while maintaining stability through the rigid organometallic core structure. The small buried volume enables fast response times without sacrificing compositional stability.
Solution Approach 2:
The patent applies local quality by designing the organometallic compound with a rigid core structure (providing local stability) and sufficient free volume around it (enabling rapid energy transfer). The stable metal-ligand coordination sphere maintains compositional integrity, while the available space allows fast response, resolving the contradiction between stability and speed.
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 compound improves the light-emitting device's performance by enhancing viewing angle, contrast ratio, response time, and luminance, while maintaining efficient energy use and stability.
Implementation Method 1
In the emission layer, these carriers, (e.g., the holes and electrons), recombine to produce excitons that may then transition (e.g., relax) from an excited state to a ground state, thereby emitting (e.g., generating) light
Implementation Method 2
the organometallic compound satisfies Condition 1: ΔG(T1) > ΔG(BDE), wherein ΔG(T1) is a triplet excited state energy of the organometallic compound
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A light-emitting device including an organometallic compound represented by Formula 1, and an electronic apparatus including the light-emitting device are provided. Also provided is the organometallic compound represented by Formula 1. A detailed description (e.g., of Formula 1) is in the specification.