Delayed Fluorescent OLED Compound Using Triplet-Singlet Conversion
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Solution Overview
Problem
Fluorescent materials used in organic light emitting diodes (OLEDs) exhibit low emitting efficiency due to the involvement of only singlet excitons in light emission, limiting their performance.
Innovation Solution
A delayed fluorescent compound is introduced, featuring an electron acceptor moiety of triazine and an electron donor moiety of indole derivative fused with a fused hetero-ring, which allows both triplet and singlet excitons to participate in light emission, enhancing efficiency through a charge transfer mechanism that bypasses the Selection Rule.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If fluorescent material is used as emitting material in OLED, then light emission is achieved, but emitting efficiency remains low due to involvement of only singlet exciton
Solution Approach 1:
The patent changes the emission mechanism parameter from conventional fluorescence to delayed fluorescence by introducing a specific molecular structure with electron donor and electron acceptor moieties. This structural parameter change enables triplet excitons to be converted into singlet excitons through reverse intersystem crossing, allowing both singlet and triplet excitons to contribute to light emission and achieving theoretical quantum efficiency of 100%
Solution Approach 2:
The delayed fluorescent compound is designed as a composite molecular structure combining electron donor moiety and electron acceptor moiety with specific structural features (fused hetero-ring, triazine group). This composite structure enables unique charge transfer mechanism that bypasses the Selection Rule and allows triplet-to-singlet exciton conversion, resolving the contradiction between light emission and energy loss
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 delayed fluorescent compound achieves high emitting efficiency, with theoretical quantum efficiency of 100%, improving the performance of OLEDs and organic light emitting display devices.
Implementation Method 1
A delayed fluorescent compound is introduced, featuring an electron acceptor moiety of triazine and an electron donor moiety of indole derivative fused with a fused hetero-ring, which allows both triplet and singlet excitons to participate in light emission
Implementation Method 2
enhancing efficiency through a charge transfer mechanism that bypasses the Selection Rule
Data Source
AI summary
The present disclosure provides a delayed fluorescent compound of following Formula, and an organic light emitting diode including a first electrode, a second electrode and an organic emitting layer between the first and second electrodes, where the delayed fluorescent compound is included in the organic emitting layer, and an organic light emitting display device including the organic emitting compound.