TY - GEN
T1 - Role of intermediate state in the excited state dynamics of highly efficient TADF molecules
AU - Hosokai, Takuya
AU - Matsuzaki, Hiroyuki
AU - Furube, Akihiro
AU - Tokumaru, Katsumi
AU - Tsutsui, Tetsuo
AU - Nakanotani, Hajime
AU - Yahiro, Masayuki
AU - Adachi, Chihaya
N1 - Funding Information:
This work was supported in part by the 'Development of Fundamental Evaluation Technology for Next-generation Chemical Materials' program commissioned by the New Energy and Industrial Technology Development Organization (NEDO), and the International Institute for Carbon Neutral Energy Research (WPI-I2CNER) sponsored by the Ministry of Education, Culture, Sports, Science and Technology (MEXT).
Publisher Copyright:
© 2016 SPIE.
PY - 2016
Y1 - 2016
N2 - 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.
AB - 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.
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U2 - 10.1117/12.2236248
DO - 10.1117/12.2236248
M3 - Conference contribution
AN - SCOPUS:85006842003
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Organic Light Emitting Materials and Devices XX
A2 - So, Franky
A2 - Adachi, Chihaya
A2 - Kim, Jang-Joo
PB - SPIE
T2 - Organic Light Emitting Materials and Devices XX
Y2 - 28 August 2016 through 30 August 2016
ER -