Budget Amount *help |
¥5,590,000 (Direct Cost: ¥4,300,000、Indirect Cost: ¥1,290,000)
Fiscal Year 2014: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2013: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2012: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
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Outline of Final Research Achievements |
Thermally activated delayed fluorescence (TADF) has been expected as a next generation emitting-mechanism of organic light-emitting diodes. Donor-acceptor systems have been reported as TADF molecules. However, it is known that non donor-acceptor systems such as C60 and Sn porphins exhibit TADF. We theoretically investigated the emitting mechanism of the non-donor-acceptor molecules to establish a novel design principle for emitting molecules. We found that the selection rules of electric dipole transition and spin-orbit coupling play crucial roles in these systems. In this mechanism, reverse intersystem crossing occurs via triplet excited state higher than T1. We call this TADF symmetry-controlled TADF. Furthermore, the energy gap can be negative. This electronic structure is called inverted singlet-triplet (iST) structure. We obtain a design principle for these novel mechanism. Based on the design principle, we succeeded in designing novel emitting molecules with the iST structure.
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