半導体ポリマーにおける活性化されたシングレットエクシトン分裂
Andrew J Musser1, Mohammed Al-Hashimi, Margherita Maiuri
1Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom. am956@cam.ac.uk
Journal of the American Chemical Society
|July 26, 2013
まとめ
シングレットエクシトン分裂は,一つの光子から直接2つのトリプルエクシトンを生成します. この研究では,このプロセスは2Agエクシトンではなく,ポリ・チエニレン・ビニレンの最初の1Buエクシトンから発生し,有機光伏に意味があることが明らかになりました.
科学分野:
- フォトフィジックスの光学
- オーガニック・エレクトロニクス
- マテリアルサイエンス 材料科学
背景:
- シングレットエクシトン分裂 (Singlet exciton fission,SEF) は,有機光伏の強化の可能性のある光物理学的プロセスである.
- SEFメカニズムを理解することは,デバイスのパフォーマンスを最適化するために不可欠です.
- 以前の研究は主に小分子における分子間SEFに焦点を当てていた.
研究 の 目的:
- 半導体ポリチエニレンビニレンのシングレットエクシトン分裂のメカニズムを調査する.
- 核分裂が発生するエクシトン状態を決定する.
- 溶液と固体フィルムの間で生成されたトリプルエクシトンの振る舞いを調査する.
主な方法:
- 核分裂過程を直接観察するために,超高速光譜法 (100 fs未満の解像度) が採用されました.
- 溶液状態と薄膜状態の両方で,ポリエチエニレンビニレン (PETV) の研究が行われました.
- エクシトンダイナミクスとトリプレット状態形成の特徴.
主要な成果:
- 100フェムト秒未満で発生する活性化されたシングレットエクシトン分裂の直接観察.
- 核分裂は最初の1Bu刺激から直接発生することを実証し,既存のモデルに挑戦した.
- 溶液では,トリプレットペアは2Ag状態を経由して急速に再結合する;フィルムでは,エキシトン拡散により長寿のトリプレットと電荷移転状態が生じる.
結論:
- この研究は,1Buエクシトンによって開始されるシングレットエクシトン分裂のための新しい経路を明らかにしています.
- 固体膜におけるエキシトンの拡散は,長寿の三胞胎を生成し,電荷の分離を可能にするために重要である.
- 発見は,効率的な有機光伏材料とデバイスの設計のための新しい洞察を提供します.
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