エクシトンの形成,リラックス,そしてPCDTBTにおける崩壊
Natalie Banerji1, Sarah Cowan, Mario Leclerc
1Center for Polymers and Organic Solids, University of California at Santa Barbara, Santa Barbara, California 93106-5090, USA.
Journal of the American Chemical Society
|November 20, 2010
まとめ
PCDTBTのようなプリスティン結合ポリマーは,ピコ秒以内にエクシトンを形成します. これらのエクシトンは,PCDTBT:フルレンの混合物での電荷移転よりもはるかに遅いプロセスで,移動し,リラックスし,超高速の電荷分離のための代替メカニズムを示唆します.
科学分野:
- オーガニック・エレクトロニクス
- 結合ポリマーの光物理学
背景:
- 結合ポリマーは,有機電子機器の重要な材料です.
- 初次刺激のダイナミクスを理解することは,デバイスの効率化にとって極めて重要です.
研究 の 目的:
- 純粋なPCDTBTにおける刺激の時間進化を調査する.
- 薄膜と溶液におけるリラックスダイナミクスを比較する.
- 光誘導電荷分離のメカニズムを明らかにする.
主な方法:
- フェムト秒解像度の光向上変換スペクトロスコーピー.
- PCDTBT薄膜および溶液に関する測定.
- 偏振に敏感で波長に依存する研究.
主要な成果:
- モバイルチャージのフォトジェネレーションに続いて,100fs以内のセルフローカライゼーションが行われます.
- <1 psで結合したシングレットエクシトンの形成.
- エクシトン移動とコンフォーマーションリラクゼーションは500fsから数十ピコ秒で起こります.
結論:
- PCDTBT:フルレンの混合物における電荷移転よりもPCDTBTにおけるエクシトンの形成と移行が遅い.
- 充電分離に先立つエクシトン拡散のモデルに異議を唱える.
- エクシトンの局所化前に超高速の電荷分離のための代替メカニズムを提案する.
関連する概念動画
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