Highly effective nicotinonitrile-derivatives-based thermally activated delayed fluorescence emitter with asymmetric molecular architecture for high-performance organic light-emitting diodes

Choi, Shin Hyung; Lee, Chan Hee; Adachi, Chihaya; Lee, Sae Youn

doi:10.1016/j.dyepig.2019.107849

Cited by 6 publications

(1 citation statement)

References 31 publications

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“…An INN segment is a strong acceptor having a CN-modified pyridine ring and can be functionalized with four donors to provide multidonor−acceptor TADF materials. 23 Instead of adding common carbazole donors, two (2BT34CzINN) or four BT34Cz donors (4BT34CzINN) were employed to modify the INN acceptor because the BT34Cz donor can redshift the emission wavelength through a strong donor and suppress DET by increasing the intermolecular distance through the bulky donor. In addition, 2BT12CzINN was synthesized by introducing BT12Cz, an isomer of BT34Cz, for further steric hindrance through a benzothiophene unit.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Suppression of Dexter Energy Transfer through Modulating Donor Segments of Thermally Activated Delayed Fluorescence Assistant Dopants

Lee

2023

ACS Appl. Mater. Interfaces

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Device degradation in red hyperfluorescent organic light-emitting diodes is primarily caused by exciton energy loss due to Dexter energy transfer (DET) from a thermally activated delayed fluorescence (TADF) assistant dopant to a fluorescent dopant. In this work, the donor segments in the TADF assistant dopants were delicately modulated to suppress DET for high efficiency. The derived benzothienocarbazole donors were introduced to the TADF assistant dopants instead of carbazole, and they accelerated the reverse intersystem crossing of the TADF assistant dopant and managed the DET from the TADF assistant dopant to the fluorescent dopant. As a result, the red TADFassisted device showed a high external quantum efficiency of 14.7% and improved the device lifetime by 70% compared to a well-known TADF-assisted device.

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Section: ■ Results and Discussionmentioning

confidence: 99%