Organic Compound Host for OLED Efficiency and Lifespan
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Solution Overview
Problem
Conventional organic light emitting diodes (OLEDs) face limitations in lifespan and emitting efficiency due to the quenching problem of excitons and energy transiting issues related to triplet energy levels in n-type hosts.
Innovation Solution
An organic compound with high triplet energy, featuring an electron acceptor moiety and electron donor moiety connected via a phenylene linker, is used as an n-type host in the emitting material layer, preventing exciton quenching and energy transiting problems, thereby improving charge balance and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional organic compounds are used as n-type hosts in OLEDs, then device operation is enabled, but exciton quenching occurs and emitting efficiency decreases
Solution Approach 1:
The patent changes the triplet energy parameter of the host compound by introducing specific molecular structures (carbazole, dibenzofuran, dibenzothiophene moieties with alkyl groups) to achieve high triplet energy (2.8-3.2 eV). This parameter change prevents exciton quenching and improves both emitting efficiency and device lifespan simultaneously.
Solution Approach 2:
The patent employs composite molecular structures combining electron-accepting carbazole groups with electron-donating dibenzofuran/dibenzothiophene groups linked by phenylene linkers. This composite structure achieves both n-type character and high triplet energy, resolving the contradiction between operational functionality and exciton stability.
2Productivity
If n-type host materials are used to improve charge balance, then electron transport is enhanced, but triplet energy loss occurs due to energy transiting problems
Solution Approach 1:
The patent optimizes the LUMO energy level parameter to -2.5 to -3.5 eV to achieve good electron transport and charge balance, while simultaneously maintaining triplet energy above 2.8 eV through specific molecular design. This dual parameter optimization resolves the energy loss issue while preserving charge balance improvement.
Solution Approach 2:
The patent introduces electron-donating dibenzofuran and dibenzothiophene moieties at specific positions on the carbazole core, creating local electron-rich regions that enhance electron transport capability while the overall molecular structure maintains high triplet energy through the rigid phenylene linker framework.
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 organic compound enhances the emitting efficiency and lifespan of OLEDs by maintaining high triplet energy and promoting charge balance, shifting the emitting zone near the interface between the emitting material layer and electron blocking layer, resulting in improved performance.
Implementation Method 1
An organic compound with high triplet energy, featuring an electron acceptor moiety and electron donor moiety connected via a phenylene linker, is used as an n-type host in the emitting material layer, preventing exciton quenching and energy transiting problems
Implementation Method 2
The organic light emitting diode emits light by injecting electrons from a cathode as an electron injection electrode and holes from an anode as a hole injection electrode into an organic emitting layer, combining the electrons with the holes, generating an exciton, and transforming the exciton from an excited state to a ground state
Data Source
AI summary
The present disclosure provides an organic compound of following formula and an organic light emitting diode and an OLED device including the organic compound.