Evidence and mechanism of efficient thermally activated delayed fluorescence promoted by delocalized excited states

被引：308

作者：

Hosokai, Takuya ^{[1
,2
]}

Matsuzaki, Hiroyuki ^{[1
,2
]}

Nakanotani, Hajime ^{[1
,2
,3
,4
,5
]}

Tokumaru, Katsumi ^{[2
]}

Tsutsui, Tetsuo ^{[2
]}

Furube, Akihiro ^{[1
,2
,8
]}

Nasu, Keirou ^{[6
]}

Nomura, Hiroko ^{[6
]}

Yahiro, Masayuki ^{[7
]}

Adachi, Chihaya ^{[3
,4
,5
]}

机构：

[1] Natl Inst Adv Ind Sci & Technol, 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 8190395, Japan

[4] Kyushu Univ, Int Inst Carbon Neutral Energy Res WPI I2CNER, Nishi Ku, 744 Motooka, Fukuoka 8190395, Japan

[5] Kyushu Univ, OPERA, Japan Sci & Technol Agcy JST, Exploratory Res Adv Technol ERATO,Adachi Mol Exci, Fukuoka 8190395, Japan

[6] Kyulux Inc, Fukuoka Ind Acad Symphon FiaS, Nishi Ku, Suite 227,Bldg 2,4-1 Kyudai Shinmachi, Fukuoka 8190388, Japan

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

[8] Univ Tokushima, Dept Opt Sci, 2-1 Minamijosanjima Cho, Tokushima 7708506, Japan

来源：

SCIENCE ADVANCES | 2017年 / 3卷 / 05期

关键词：

LIGHT-EMITTING DIODE; TRANSIENT ABSORPTION-SPECTROSCOPY; ELECTRON INJECTION EFFICIENCY; QUANTUM EFFICIENCY; EMITTERS; SOLVENTS; OLEDS; FILMS; TIO2;

D O I：

10.1126/sciadv.1603282

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

The design of organic compounds with nearly no gap between the first excited singlet (S-1) and triplet (T-1) states has been demonstrated to result in an efficient spin-flip transition from the T-1 to S-1 state, that is, reverse intersystem crossing (RISC), and facilitate light emission as thermally activated delayed fluorescence (TADF). However, many TADF molecules have shown that a relatively appreciable energy difference between the S-1 and T-1 states (similar to 0.2 eV) could also result in a high RISC rate. We revealed from a comprehensive study of optical properties of TADF molecules that the formation of delocalized states is the key to efficient RISC and identified a chemical template for these materials. In addition, simple structural confinement further enhances RISC by suppressing structural relaxation in the triplet states. Our findings aid in designing advanced organic molecules with a high rate of RISC and, thus, achieving the maximum theoretical electroluminescence efficiency in organic light-emitting diodes.

引用

页数：9

共 35 条

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