Structural analysis of organic device materials by DNP-NMR

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K15648
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 35030:Organic functional materials-related
• Research Institution: Kyoto University
• Principal Investigator: Suzuki Katsuaki 京都大学, 化学研究所, 助教 (90747859)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 有機EL / 固体NMR

Outline of Final Research Achievements

In this study, the torsion angle of the thermally active delayed fluorescent (TADF) material was evaluated by combining dynamic nuclear polarization NMR (DNP-NMR) and quantum chemical calculations. Specifically, by using DNP-NMR, a significant improvement in the sensitivity of the 15N NMR spectrum could be achieved, and a signal with good S / N was obtained in a short time. Based on the results, we succeeded in evaluating the donor and acceptor torsion angle of a TADF emitter. We have also worked on optimizing the measurement conditions of DNP-NMR under static conditions, and have obtained the best sensitivity improvement per unit time when a biradical sensitizer is used. It has become possible to analyze the orientation distribution of the film thickness of about 200 nm actually used in the device. In addition, we were able to develop research on light-irradiated DNP-NMR and conformation analysis including distribution.

Free Research Field

有機機能材料

Academic Significance and Societal Importance of the Research Achievements

本研究成果はこれまで、不可能であった、非晶膜中における有機EL発光材料のコンフォメーション解析を初めて行った例である。この成果を他の材料へさらに適用することにより、有機EL発光材料の構造ー物性相関の解明につながり、より高効率な材料の開発につながっていくと期待される。