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

被引：1

作者：

Hosokai, Takuya ^{[1
,2
]}

Matsuzaki, Hiroyuki ^{[1
,2
]}

Furube, Akihiro ^{[1
,2
,7
]}

Tokumaru, Katsumi ^{[2
]}

Tsutsui, Tetsuo ^{[2
]}

Nakanotani, Hajime ^{[3
,4
,5
]}

Yahiro, Masayuki ^{[3
,4
,6
]}

Adachi, Chihaya ^{[3
,4
]}

机构：

[1] Natl Inst Adv Ind Sci & Technol, Natl Metrol Inst Japan, Tsukuba Cent 2,1-1-1 Umezono, Tsukuba, Ibaraki 3058568, Japan

[2] Chem Mat Evaluat & Res Base CEREBA, 1-1-1 Higashi, Tsukuba, Ibaraki 3058561, Japan

[3] Kyushu Univ, Ctr Organ Photon & Elect Res OPERA, Nishi Ku, 744 Motooka, Fukuoka 8290395, Japan

[4] Kyushu Univ, Int Inst Carbon Neutral Energy Res WPI I2 CNER, Nishi Ku, 744 Motooka, Fukuoka 8190395, Japan

[5] Kyushu Univ, OPERA, Adachi Mol Exciton Engn Project, ERATO,JST,Nishi Ku, 744 Motooka, Fukuoka 8190395, Japan

[6] Inst Informat Technol & Nanotechnol ISIT, Nishi Ku, Fukuoka 8190388, Japan

[7] Univ Tokushima, Dept Opt Sci, 2-1 Minamijosanjima Cho, Tokushima, Japan

来源：

ORGANIC LIGHT EMITTING MATERIALS AND DEVICES XX | 2016年 / 9941卷

关键词：

TADF; delayed fluorescence; excited-state dynamics; transient absorption spectroscopy; intermediate state; delocalized excited state; RISC; reverse intersystem crossing; ACTIVATED DELAYED FLUORESCENCE; LIGHT-EMITTING-DIODES; MECHANISM; COMPLEXES; EMITTERS;

D O I：

10.1117/12.2236248

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

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.

引用

页数：6

共 27 条

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