Investigation of mechanisms of thermally activated delayed fluorescence using multi-excitation transient spectroscopy

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K15508
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 32010:Fundamental physical chemistry-related
• Research Institution: Kyushu University
• Principal Investigator: Miyata Kiyoshi 九州大学, 理学研究院, 助教 (80808056)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: 光機能性材料 / 熱活性化遅延蛍光 / 超高速分光 / 高次励起状態 / 光化学 / 励起状態ダイナミクス

Outline of Final Research Achievements

To elucidate the mechanism of thermally activated delayed fluorescence (TADF) materials at the molecular level, we developed two approaches in parallel: 1) experimental observation of vibrational spectra of excited states using time-resolved infrared spectroscopy, and 2) observation of higher-order excited states by applying the pump-push-probe method. We elucidated the changes in the molecular conformation upon excitation of multi-resonant TADF molecules and donor-acceptor molecules. We also constructed a pump-push-probe system, and were able to detect the dynamics of some TADF molecules from the higher-order triplet excited state.

Free Research Field

物理化学、分光分析

Academic Significance and Societal Importance of the Research Achievements

熱活性化遅延蛍光材料は未来のエレクトロニクスを拓く可能性のある重要な物質群であり、今回この材料群の分子レベルでの設計指針に繋がる知見が得られたのは価値が高い。特に分子の高次励起状態の分析は最先端の科学でも未踏学術領域の一つであり、今回測定手法を開発できた点は今後の分子エレクトロニクスに限らず光化学反応など多くの光励起状態を利用する現象のメカニズム解明につながる可能性がある。