| Title |
Exciplex-forming systems of physically mixed and covalently bonded benzoyl-1H-1,2,3-triazole and carbazole moieties for solution-processed white OLEDs / |
| Authors |
Stanitska, Mariia ; Mahmoudi, Malek ; Pokhodylo, Nazariy ; Lytvyn, Roman ; Volyniuk, Dmytro ; Tomkeviciene, Ausra ; Keruckiene, Rasa ; Obushak, Mykola ; Grazulevicius, Juozas Vidas |
| DOI |
10.1021/acs.joc.1c02784 |
| Full Text |
|
| Is Part of |
Journal of organic chemistry.. Washington, DC : American chemical society. 2022, vol. 87, iss. 6, p. 4040-4050.. ISSN 0022-3263. eISSN 1520-6904 |
| Keywords [eng] |
color ; triazole ; layers ; aromatic compounds ; diodes |
| Abstract [eng] |
Using the newly designed exciplex-forming 1,2,3-triazole-based acceptors with fast and efficient singlet → triplet intersystem crossing (ISC) processes, carbazole and benzoyl-1H-1,2,3-triazole derivatives were synthesized by Dimroth-type 1,2,3-triazole ring formation and Ullmann-Goldberg C-N coupling reactions. Due to the exciplex formation between covalently bonded electron-donating (carbazole) and 1,2,3-triazole-based electron-accepting moieties with small singlet-triplet splitting (0.07-0.13 eV), the compounds exhibited ISC-assisted bluish-green thermally activated delayed fluorescence. The compounds were characterized by high triplet energy levels ranging from 2.93 to 2.98 eV. The most efficient exciplex-type thermally activated delayed fluorescence was observed for ortho-substituted carbazole-benzoyl-1H-1,2,3-triazole which was selected as a host in the structure of efficient solution-processed white light-emitting diodes. The best device exhibited a maximum power efficiency of 10.7 lm/W, current efficiency of 18.4 cd/A, and quantum efficiency of 7.1%. This device also showed the highest brightness exceeding 10 thousand cd/m2. Usage of the exciplex-forming host allowed us to achieve a low turn-on voltage of 3.6 V. High-quality white electroluminescence was obtained with the close to nature white color coordinates (0.31, 0.34) and a color rendering index of 92. |
| Published |
Washington, DC : American chemical society |
| Type |
Journal article |
| Language |
English |
| Publication date |
2022 |
| CC license |
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