Carbazole Derivatives with Thermally Activated Delayed Fluorescence Property as Photoinitiators/Photoredox Catalysts for LED 3D Printing Technology

2017 ◽  
Vol 50 (13) ◽  
pp. 4913-4926 ◽  
Author(s):  
Assi Al Mousawi ◽  
Diego Magaldi Lara ◽  
Guillaume Noirbent ◽  
Frederic Dumur ◽  
Joumana Toufaily ◽  
...  
Keyword(s):  
3D Printing ◽  
Delayed Fluorescence ◽  
Fluorescence Property ◽  
Printing Technology ◽  
Thermally Activated Delayed Fluorescence ◽  
Carbazole Derivatives ◽  
3D Printing Technology ◽  
Thermally Activated

scholarly journals Impurity Conundrum of Organic Room Temperature Afterglow

2019 ◽  
Author(s):  
Chengjian Chen ◽  
Zhenguo Chi ◽  
Kok Chan Chong ◽  
Andrei S. Batsanov ◽  
Zhan Yang ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
Room Temperature ◽  
Functional Materials ◽  
Delayed Fluorescence ◽  
Impurity Effect ◽  
Thermally Activated Delayed Fluorescence ◽  
Carbazole Derivatives ◽  
Thermally Activated ◽  
Commercial Sources ◽  
Triplet Excited States

<p>Commercial carbazole has been widely used to synthesize organic functional materials that entwine with the recent breakthroughs in thermally activated delayed fluorescence, organic luminescent radicals and organic laser diodes. Recently, the strategy of stabilizing triplet excited states in carbazole derivatives ignited the booming development of organic room temperature afterglow (RTA). The unusual RTA of carbazole and its derivatives was elaborated by crystal quality and packing. However, impurity hypotheses in organic RTA have been under debate for nearly a century. Here we show that an isomer of carbazole, accompanying the commercial sources with less than 0.5%, is the key to activating RTA for many carbazole derivatives. As compared to commercial carbazole, the fluorescence of lab-synthesized carbazole is blue-shifted by 54 nm and the well-known RTA disappears. The same phenomenon is also observed for a series of carbazole derivatives. Interestingly, even 0.01% isomer doping could yield the reported RTA. Our results demonstrate that the isomer doping in carbazole derivatives is responsible for their RTA. The impurity effect has also been confirmed for <a>dibenzothiophene</a> based RTA. We anticipate that isomer doping effect is applicable to many organic semiconductors derived from commercial carbazole, which will drive the review of organic functional materials in optoelectronics.</p>

Transfer printing of polymer light-emitting devices with a small molecular seeding layer featuring thermally activated delayed fluorescence for triplet harvesting

2020 ◽  
Vol 5 (1) ◽  
pp. 144-149 ◽  
Author(s):  
Yang Tang ◽  
Yuhan Gao ◽  
Guohua Xie ◽  
Chuluo Yang
Keyword(s):  
Delayed Fluorescence ◽  
Transfer Printing ◽  
Printing Technology ◽  
Seeding Layer ◽  
Thermally Activated Delayed Fluorescence ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Thermally Activated ◽  
Polymer Light Emitting Devices ◽  
Triplet Harvesting

Transfer-printing technology combined with a TADF-based HTL realized a 2-fold enhancement of EL efficiency for a polymer fluorescence emitter.

Thermally Activated Delayed Fluorescence (Green) in Undoped Film and Exciplex Emission (Blue) in Acridone–Carbazole Derivatives for OLEDs

2018 ◽  
Vol 123 (2) ◽  
pp. 1003-1014 ◽  
Author(s):  
Qamar T. Siddiqui ◽  
Ankur A. Awasthi ◽  
Prabhjyot Bhui ◽  
Mohammad Muneer ◽  
Kuttay R. S. Chandrakumar ◽  
...  
Keyword(s):  
Delayed Fluorescence ◽  
Undoped Film ◽  
Thermally Activated Delayed Fluorescence ◽  
Carbazole Derivatives ◽  
Thermally Activated ◽  
Exciplex Emission

Blue thermally activated delayed fluorescence materials based on bi/tri-carbazole derivatives

2018 ◽  
Vol 58 ◽  
pp. 238-244 ◽  
Author(s):  
Wenjuan Zhang ◽  
Ye-Xin Zhang ◽  
Xiao-Qing Zhang ◽  
Xiang-Yang Liu ◽  
Jian Fan ◽  
...  
Keyword(s):  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Carbazole Derivatives ◽  
Thermally Activated

scholarly journals Impurity Conundrum of Organic Room Temperature Afterglow

2019 ◽  
Author(s):  
Chengjian Chen ◽  
Zhenguo Chi ◽  
Kok Chan Chong ◽  
Andrei S. Batsanov ◽  
Zhan Yang ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
Room Temperature ◽  
Functional Materials ◽  
Delayed Fluorescence ◽  
Impurity Effect ◽  
Thermally Activated Delayed Fluorescence ◽  
Carbazole Derivatives ◽  
Thermally Activated ◽  
Commercial Sources ◽  
Triplet Excited States

<p>Commercial carbazole has been widely used to synthesize organic functional materials that entwine with the recent breakthroughs in thermally activated delayed fluorescence, organic luminescent radicals and organic laser diodes. Recently, the strategy of stabilizing triplet excited states in carbazole derivatives ignited the booming development of organic room temperature afterglow (RTA). The unusual RTA of carbazole and its derivatives was elaborated by crystal quality and packing. However, impurity hypotheses in organic RTA have been under debate for nearly a century. Here we show that an isomer of carbazole, accompanying the commercial sources with less than 0.5%, is the key to activating RTA for many carbazole derivatives. As compared to commercial carbazole, the fluorescence of lab-synthesized carbazole is blue-shifted by 54 nm and the well-known RTA disappears. The same phenomenon is also observed for a series of carbazole derivatives. Interestingly, even 0.01% isomer doping could yield the reported RTA. Our results demonstrate that the isomer doping in carbazole derivatives is responsible for their RTA. The impurity effect has also been confirmed for <a>dibenzothiophene</a> based RTA. We anticipate that isomer doping effect is applicable to many organic semiconductors derived from commercial carbazole, which will drive the review of organic functional materials in optoelectronics.</p>

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