マルチフォノンリラクゼーションは,結晶ヘクサセンのシングレット分裂を遅らせます

Erik Busby¹, Timothy C Berkelbach, Bharat Kumar

¹Energy Frontier Research Center, ¶Department of Chemistry, and §Departments of Physics and Electrical Engineering, Columbia University , New York, New York 10027, United States.

Journal of the American Chemical Society

|July 2, 2014

まとめ

ヘクサセンの結晶のシングレット分裂は530fsで発生し,太陽電池の効率を高めるためにアセンの材料設計の洞察を提供します. この研究は,シングレット分裂速度のメカニズム的傾向を明らかにしています.

科学分野:

マテリアルサイエンス材料科学
フォトケミストリーは,写真化学です.
オーガニック・エレクトロニクス

背景:

シングレット分裂 (SF) は,1つのシングレット刺激を2つのトリプル刺激に変換するプロセスです.
SFは,太陽電池の効率を高めるための有望な戦略です.
SFメカニズムを理解することは,新しい材料の設計に不可欠です.

研究の目的:

メカニズムの傾向を理解するために,結晶ヘクサセンのSFを調査します.
アセネ族 (ペンタセネ,テトラセネ,ヘクサセネ) のSF率を比較する.
SFレートの理論的枠組みを策定する.

主な方法:

ヘクサセンの静的および一時的な光学吸収の特徴.
電子カップリングとSF率の理論分析.
顕微鏡理論の開発. 顕微鏡理論の開発.

主要な成果:

ヘクサセンは530fsのSF時間スケールを示しています.
ヘクサセンのSFはテトラセン (10-100 ps) よりも著しく速いが,ペンタセン (80-110 fs) よりも遅い.
大量のエクソ熱性によるマルチフォノンリラクゼーション効果は,ヘクサセンのSF率を説明する.

結論:

SFのメカニズム的傾向は,アセネ族を研究することによって解明することができます.
開発された顕微鏡理論は,アセンのSF率を定量的に予測する.
発見は,太陽エネルギーアプリケーションのためのSF材料の合理的な設計のための基盤を提供します.

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