1984-49-2Relevant articles and documents
Molecular engineering of “A-D-D-A” dual-emitting-cores emitters with thermally activated delayed fluorescence and aggregation-induced emission characteristics
Sun, Yibai,Sun, Yueming,Tang, Jinan,Tang, Qifeng
, (2021)
Endowing thermally activated delayed fluorescence (TADF) emitter with aggregation-induced emission (AIE) peculiarity is of great significance for realizing more promising commercial applications. Herein, two new dual-emitting-cores emitters with a structu
An effective thermally activated delayed fluorescence host material for highly efficient blue phosphorescent organic light-emitting diodes with low doping concentration
Liu, Yan,Pan, Jie,Chen, Feng,Gao, Kun,Zhu, Aiyun,Wang, Ruoxian,Yue, Xuan,Ban, Xinxin
, (2020)
A thermally activated delayed fluorescence (TADF) material BCz-2SO has been designed and synthesized as host for blue phosphorescent organic light-emitting diodes (OLEDs). Photophysical studies and theoretical calculations show that the molecule has a small singlet-triplet energy gap (ΔEST) of 0.345 eV, which is beneficial to the reverse energy transferring between the singlet and triplet state. Thanks to the TADF property, the triplet energy can be transmitted to the singlet state through reverse intersystem crossing (RISC), and then transmitted to the guest through the Fo?rster energy transfer (FET) to achieve 100% utilization of energy. Thus, the triplet–triplet annihilation (TTA) of the blue phosphor can be avoided by the extremely low doping concentration of 1%. By using BCz-2SO as the host of FIrpic, the solution-processed blue phosphorescent device achieves the maximum current efficiency (CE), power efficiency (PE), external quantum efficiency (EQE) and highest brightness of 16.38 cd A?1, 9.04 lm W?1, 7.8% and 16,537 cd m-2, respectively. It demonstrates that one can employ the solution-processed method to prepare the high performance phosphorescent OLEDs using the TADF host material we have developed.
A thermally cross-linkable hole-transporting small-molecule for efficient solution-processed organic light emitting diodes
Dubey, Deepak Kumar,Swayamprabha, Sujith Sudheendran,Kumar Yadav, Rohit Ashok,Tavgeniene, Daiva,Volyniuk, Dmytro,Grigalevicius, Saulius,Jou, Jwo-Huei
, p. 94 - 101 (2019)
Fabrication of multilayered organic light-emitting diodes (OLEDs) through solution process involves several challenges, especially in preventing dissolution of prior layers during subsequent coating. To overcome, extensive efforts had been made in developing cross-linkable materials. In this work, a thermally cross-linkable hole-transporting material, (9,9′-bis(4-vinylbenzyl)-9H,9′H-3,3′-bicarbazole) (VyPyMCz), is synthesized, characterized and successfully applied to multilayered OLEDs via solution-process. After cross-linking, the hole-transporting material forms robust, smooth and solvent-resistant network, enabling a subsequent spin-coating without deteriorating its film integrity. The measured energy level suggests that VyPyMCz facilitates the injection of hole and effectively blocks electron to realize high efficiency, especially at high luminance. At 1000 cd m?2 for example, the power efficiency of a studied red device is increased from 7.5 to 11.9 lm W?1, an increment of 58%, and the maximum brightness improved from 7724 to 13,560 cd m?2, an increment of 75%, as this electron confining, hole transporting material is incorporated. Remarkably, VyPyMCz also works for a high band gap (2.90 eV) with a high triplet energy (2.80 eV) blue emitter containing OLED device, the power efficiency is increased from 6.6 to 11.8 lm W?1, an increment of 78%, and the maximum luminance enhanced from 5260 to 6857 cd m?2, an increment of 30%, because of its higher triplet energy (2.87 eV).
Synthesis of new bicarbazole-linked triazoles as non-cytotoxic reactive oxygen species (ROS) inhibitors
Iqbal, Shazia,Khan, Maria A.,Ansari, Zulqarnain,Jabeen, Almas,Faheem, Aisha,Fazal-Ur-Rehman, Saba,Basha, Fatima Z.
supporting information, p. 2330 - 2341 (2019/07/05)
Carbazole analogs 3 and 4 and a new library of bicarbazole-linked triazoles 6–11 were prepared via new synthetic methodology. Metal-catalyzed oxidative coupling reaction was utilized for the synthesis of bicarbazole acetylene 4 and different metals (Znsu