Investigation of energy and charge transfer dynamics in lanthanide complexes using electric-field modulated transient spectroscopy

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K14590
• 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, 大学院理学研究院, 准教授 (80808056)
• Project Period (FY): 2021-04-01 – 2023-03-31
• Keywords: 発光性希土類錯体 / 時間分解分光 / 光化学 / 発光材料 / エネルギー移動 / 有機EL

Outline of Final Research Achievements

In our research, we aimed to elucidate the photoluminescence mechanisms in luminescent lanthanide complexes, specifically focusing on the energy transfer between organic ligands and lanthanide ions. We accomplished several key findings: the elucidation of the dynamics of level-selective intramolecular energy transfer in trivalent europium complexes; understanding the activation barrier for forward/reverse energy transfer in trivalent terbium complexes; and the creation of highly luminescent thin films of trivalent europium through host-guest sensitization. Additionally, we developed a spectroscopic device for observing the dynamics under an electric field. This work advances our understanding of energy transfer in luminescent lanthanide complexes, offering potential for future development in optoelectronics.

Free Research Field

光物理化学

Academic Significance and Societal Importance of the Research Achievements

希土類イオンの演色性の高い発光は更なる応用の観点から意義があるが、高効率化の鍵となる配位子-希土類イオン間のエネルギー移動は未解明な点が多く、高効率化のデザイン指針は必ずしも確立されていない。希土類イオンは4f軌道由来の多彩な電子配置を取るため、基底状態・励起状態ともに様々なスピン多重度を有し、有機配位子が取り得る一重項・三重項とは異なる。従って配位子-希土類イオンのエネルギー移動はスピン転換を伴う電子ダイナミクスであり、この電子・構造・スピンの自由度が関わる複雑なメカニズムを独自の時間分解分光のアプローチから解明した点は基礎分子科学としても意義が大きい。