Triphenylene Benzo-Fused Thiophene Hosts for OLED Energy Quenching
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Solution Overview
Problem
Current organic light emitting devices (OLEDs) face challenges in achieving high efficiency and stability, particularly in accommodating red, green, and blue phosphorescent dopants without energy quenching, and in balancing charge transport for improved device performance.
Innovation Solution
The development of triphenylene-containing benzo-fused thiophene and furan compounds, which serve as hosts or enhancement layers in OLEDs, offering high triplet energy and improved charge balance, thereby enhancing device efficiency and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional host materials are used in OLEDs, then device fabrication is simpler, but energy quenching occurs between host and phosphorescent dopants, reducing device efficiency
Solution Approach 1:
The patent changes the energy parameter of the host material by incorporating triphenylene groups with high triplet energy levels (2.9-3.2 eV), which exceeds the energy of common phosphorescent dopants. This parameter change prevents energy quenching while maintaining compatibility with standard OLED fabrication processes
Solution Approach 2:
The patent creates composite host materials by combining triphenylene core structures with various substituents (carbazole, dibenzothiophene, dibenzofuran groups) to achieve both high triplet energy and good charge transport properties, resolving the contradiction between energy matching and device performance
2Reliability
If standard organic materials are used in OLEDs, then cost is lower, but charge transport balance is poor, reducing device performance
Solution Approach 1:
The patent applies local quality by introducing specific functional groups (carbazole for hole transport, dibenzothiophene/dibenzofuran for electron transport) at strategic positions on the triphenylene core, creating molecules with balanced charge transport properties while maintaining overall structural simplicity
Solution Approach 2:
The triphenylene-based host molecules serve multiple functions simultaneously: providing high triplet energy for phosphorescence, enabling balanced charge transport through integrated functional groups, and ensuring good film-forming properties, thereby improving reliability without proportionally increasing complexity
3Duration of action of moving object
If OLEDs use phosphorescent dopants with standard hosts, then device structure is simpler, but device lifetime is short due to energy quenching
Solution Approach 1:
The patent changes the triplet energy parameter of the host material to 2.9-3.2 eV through triphenylene incorporation, which is higher than typical phosphorescent dopants (2.1-2.6 eV), preventing energy back-transfer and quenching, thereby extending device lifetime while maintaining manageable structural complexity
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
These compounds provide high efficiency and stability in OLEDs by accommodating phosphorescent dopants without energy quenching and improving charge balance, leading to extended device lifetime and performance.
Implementation Method 1
One application for phosphorescent emissive molecules is a full color display
Implementation Method 2
accommodating red, green, and blue phosphorescent dopants without energy quenching
Data Source
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AI summary
A compound comprising a triphenylene containing benzo-fused thiophene or benzo-fused furan, wherein the compound is represented by the structure of Formula (IV) or Formula (V): wherein X is S or O; wherein R1, R2, and R3 are unfused substituents independently selected from the group consisting of CnH2n+1, OCnH2n+1, OAr1, N(CnH2n+1)2, N(Ar1)(Ar2), CH=CH-CnH2n+1, C≡C-CnH2n+1, Ar1, Ar1-Ar2, CnH2n-Ar1, or no substitution, and wherein each of R1, R2, and R3 may represent mono, di, tri, or tetra substitutions; wherein n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; wherein Ar1 and Ar2 are independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and heteroaromatic analogs thereof; and wherein at least one of R1, R2, and R3 includes a triphenylene group.