Hybridized local and charge transfer dendrimers with near-unity exciton utilization for enabling high-efficiency solution-processed hyperfluorescent OLEDs
- Authors
- Yin, Yixiao; Zeng, Songkun; Xiao, Chen; Fan, Peng; Shin, Dong Jin; Kim, Ki Ju; Nam, Hyewon; Ma, Qian; Ma, Huili; Zhu, Weiguo; Kim, Taekyung; Lee, Jun Yeob; Wang, Yafei
- Issue Date
- 16-Jan-2024
- Publisher
- ROYAL SOC CHEMISTRY
- Citation
- MATERIALS HORIZONS, v.11, no.7, pp 1741 - 1751
- Pages
- 11
- Journal Title
- MATERIALS HORIZONS
- Volume
- 11
- Number
- 7
- Start Page
- 1741
- End Page
- 1751
- URI
- https://scholarworks.bwise.kr/hongik/handle/2020.sw.hongik/32708
- DOI
- 10.1039/d3mh01860a
- ISSN
- 2051-6347
2051-6355
- Abstract
- Achieving both high emission efficiency and exciton utilization efficiency (eta S) in hot exciton materials is still a formidable task. Herein, a proof-of-concept design for improving eta S in hot exciton materials is proposed via elaborate regulation of singlet-triplet energy difference, leading to an additional thermally activated delayed fluorescence (TADF) process. Two novel dendrimers, named D-TTT-H and D-TTT-tBu, were prepared and characterized, in which diphenylamine derivatives were used as a donor moiety and tri(triazolo)triazine (TTT) as an acceptor fragment. Compounds D-TTT-H and D-TTT-tBu showed an intense green color with an emission efficiency of approximately 80% in solution. Impressively, both dendrimers simultaneously exhibited a hot exciton process and TADF characteristic in the solid state, as was demonstrated via theoretical calculation, transient photoluminescence, magneto-electroluminescence and transient electroluminescence measurements, thus achieving almost unity eta S. A solution processable organic light-emitting diode (OLED) employing the dendrimer as a dopant represents the best performance with the highest luminance of 15090 cd m-2 and a maximum external quantum efficiency (EQEmax) of 11.96%. Moreover, using D-TTT-H as a sensitizer, an EQEmax of 30.88%, 24.08% and 14.33% were achieved for green, orange and red solution-processed OLEDs, respectively. This research paves a new avenue to construct a fluorescent molecule with high eta S for efficient and stable OLEDs. Two dendrimers, called D-TTT-H and D-TTT-tBu, were prepared, which exhibits both hot exciton process and TADF characteristic simultaneously in solid state. The solution processable OLED showed an EQEmax of 30.88% employing D-TTT-H as a sensitizer.
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Collections - College of Science and Technology > School of Materials Science and Engineering > 1. Journal Articles
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