| 研究課題/領域番号 |
24KF0245
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| 研究機関 | 九州大学 |
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研究代表者 |
安達 千波矢 九州大学, 工学研究院, 教授 (30283245)
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| 研究分担者 |
BARMAN DEBASISH 九州大学, 工学研究院, 外国人特別研究員
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| 研究期間 (年度) |
2024-11-15 – 2027-03-31
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| キーワード | Multiresonance / charge transfer / molecular orientation / TADF / EQE |
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| 研究実績の概要 |
We summarize our approach with two simple donor-acceptor (D-A) and donor-acceptor-donor (D-A-D) design strategies, which combine short-range (SR) charge transfer (CT) with main long-range (LR) CT, resulting in multi-resonance (MR) CT-type thermally activated delayed fluorescence (TADF) emitters. By modifying the auxiliary push-pull connection between a carbazole donor and a boron-based acceptor core, we constructed C-C bond-extended DBACzPh and DBADCzPh emitters with strong TADF emission in solution and thin films. Preferential 100% horizontal molecular orientation resulted in balanced bipolar carrier transport and effective host-to-dopant energy transfer in a high-polarity host matrix. Thereby, DBADCzPh significantly boosts outcoupling efficiency with a record-high EQE of over 40%.
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| 現在までの達成度 |
現在までの達成度
1: 当初の計画以上に進展している
理由
We successfully synthesized two of the proposed emitters. Afterward, we could obtain feasible optical properties. Further, evaluate the exclusive photophysics and device physics of the synthesized emitters as planned.
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| 今後の研究の推進方策 |
We summarize all the obtained results and prepare them for publication. Unlike very high EQE, the device lifetime of these emitters was not satisfactory for the sky-blue emitter. Therefore, we plan to synthesize cyclic MRCT-type D-A-D-A structures to achieve blue emission with improved operational device lifetime. We believe that a cyclic framework could reduce molecular vibration and enhance molecular stability, thereby reducing the likelihood of unnecessary chemical degradation. At the same time, the reverse intersystem crossing rate is also expected to be enhanced by the molecular rigidity factor.
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