Role of intermediate state in the excited state dynamics of highly efficient TADF molecules

Takuya Hosokai, Hiroyuki Matsuzaki, Akihiro Furube, Katsumi Tokumaru, Tetsuo Tsutsui, Hajime Nakanotani, Masayuki Yahiro, Chihaya Adachi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)


We hereby report the results of our direct investigation into the excited-state dynamics of thermally activated delayed fluorescence (TADF) molecules in solution using pump-probe transient absorption spectroscopy (TAS). We found that the charge-transfer (CT) state commonly stated for TADF molecules encompasses two forms: localized and delocalized CT states. A highly efficient TADF molecule, 4CzIPN [Uoyama et al., Nature, 492, 234-238 (2012)], showed both the localized and delocalized CT states, while an inefficient TADF molecule, 2CzPN, exhibited only a localized CT state. By analyzing the time profile of triplet species observed in TAS, we propose that the reverse intersystem crossing (RISC) of 4CzIPN occurs via a mutual interaction in multiple energy levels of localized neutral and CT states, and delocalized CT states.

Original languageEnglish
Title of host publicationOrganic Light Emitting Materials and Devices XX
EditorsFranky So, Chihaya Adachi, Jang-Joo Kim
ISBN (Electronic)9781510602731
Publication statusPublished - 2016
EventOrganic Light Emitting Materials and Devices XX - San Diego, United States
Duration: Aug 28 2016Aug 30 2016

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherOrganic Light Emitting Materials and Devices XX
Country/TerritoryUnited States
CitySan Diego

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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