Boron-Containing Organic Compound for OLED Efficiency
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Solution Overview
Problem
Current organic light-emitting diodes (OLEDs) face limitations in luminous efficiency and lifetime due to the roll-off effect at high luminance, and the high cost and rarity of rare metal complexes used in phosphorescent materials, while thermally activated delayed fluorescence (TADF) materials still have efficiency and lifetime performance differences compared to phosphorescent materials.
Innovation Solution
A boron-containing organic compound with a specific molecular structure that facilitates thermally activated delayed fluorescence, allowing for a non-D-A configuration and a small energy level difference between singlet and triplet excited states, enabling efficient reverse intersystem crossing and improved luminous efficiency and lifetime in organic electronic devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If phosphorescent materials are used to achieve high internal electroluminescence quantum efficiency, then luminous efficiency is improved, but roll-off effect occurs at high luminance causing luminous efficiency to decrease rapidly
Solution Approach 1:
The patent changes the energy level parameters of the organic compound by introducing a boron-containing heterocyclic ring structure, which modifies the HOMO and LUMO energy levels to achieve a small energy gap between singlet and triplet excited states. This parameter change enables efficient reverse intersystem crossing while maintaining high luminous efficiency and reducing the roll-off effect at high luminance.
2Productivity
If phosphorescent materials including iridium or platinum are used to achieve high efficiency, then internal electroluminescence quantum efficiency is improved, but manufacturing cost increases due to rarity and complexity of synthesis
Solution Approach 1:
The patent replaces expensive and rare metal complexes (iridium or platinum) with inexpensive organic compounds containing boron-containing heterocyclic ring structures. These organic materials can be synthesized through relatively simple and economical routes, significantly reducing manufacturing cost while maintaining high internal electroluminescence quantum efficiency through the reverse intersystem crossing mechanism.
3Use of energy by moving object
If TADF materials with electron-donating group linked to electron-accepting group are used to reduce energy level difference, then reverse intersystem crossing is enabled, but efficiency and lifetime performance still differ from phosphorescent materials
Solution Approach 1:
The patent creates a composite molecular structure by introducing a boron-containing heterocyclic ring structure that integrates both electron-donating and electron-accepting characteristics within a single molecular framework. This composite structure achieves a small energy gap between singlet and triplet excited states while providing enhanced efficiency and lifetime performance compared to conventional TADF materials, bridging the performance gap with phosphorescent 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 boron-containing organic compound enhances the luminous efficiency and extends the lifetime of organic electronic devices while reducing manufacturing costs, achieving high efficiency and low roll-off effects, making it suitable for use in OLEDs and other opto-electronic applications.
Implementation Method 1
Adachi proposed the concept of reverse intersystem crossing, which allows the use of organic compounds, i.e., without using metal complexes, to achieve high efficiencies comparable to phosphorescent OLEDs. This concept has been achieved through various combinations of materials, such as: 1) using exciplex, see Adachi et al., Nature Photonics, Vol. 6, p 253 (2012); 2) using thermally activated delayed fluorescence (TADF) materials, see Adachi et al., Nature, Vol. 492, 234, (2012).
Implementation Method 2
Adachi proposed the concept of reverse intersystem crossing, which allows the use of organic compounds, i.e., without using metal complexes, to achieve high efficiencies comparable to phosphorescent OLEDs.
Data Source
AI summary
An organic compound containing boron and uses thereof, an organic mixture, and an organic electronic device, the structure of said organic compound containing boron being as shown in formula (1). The substituents in formula (I) have the same definitions as in the description.