Elucidation and Control of Advanced Photofunctions based on Excited States in Molecular Materials
- PC Department Seminar
- Date: Jul 1, 2024
- Time: 11:00 AM (Local Time Germany)
- Speaker: Kiyoshi Miyata
- Kyushu University, Japan
- Location: Building G
- Room: 2.06
- Host: Sebastian Mährlein
Microscopic understanding of exciton physics in molecular materials for optoelectronics is a great challenge because of their complexity resulting from strong electron-phonon coupling and perhaps interaction to spin degree of freedom, electron spin-flip of intersystem crossing in molecular optoelectronic materials are strongly connected to molecular geometries in the excited states and vibronic coupling, and singlet fission, ultrafast generation of a correlated triplet pair state from a singlet excited state, is viewed as an extreme example of a concerted process of electron-phonon-spin degrees of freedom. To understand the complex exciton dynamics, direct observation of exciton dynamics using ultrafast spectroscopy is a key. Here, I would like to discuss a few topics mainly focusing on triplet excited state based photofunctions: Reverse intersystem crossing (RISC), room temperature phosphorescence (RTP), triplet-triplet energy transfer (TTET), and singlet fission (SF). Using ultrafast spectroscopy such as transient absorption, time-resolved emission spectroscopy, time-resolved infrared spectroscopy, we revealed microscopic mechanisms of the photofunctions from molecular point of view, which allows us to control the functionality.
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