Observation of Two Triplet-Pair Intermediates in Singlet Exciton Fission

被引：208

作者：

Pensack, Ryan D. ^{[1
]}

Ostroumov, Evgeny E. ^{[1
]}

Tilley, Andrew J. ^{[2
]}

Mazza, Samuel ^{[3
]}

Grieco, Christopher ^{[4
]}

Thorley, Karl J. ^{[3
]}

Asbury, John B. ^{[4
]}

Seferos, Dwight S. ^{[2
]}

Anthony, John E. ^{[3
]}

Scholes, Gregory D. ^{[1
]}

机构：

[1] Princeton Univ, Dept Chem, Princeton, NJ 08544 USA

[2] Univ Toronto, Dept Chem, Toronto, ON M5S 3H6, Canada

[3] Univ Kentucky, Dept Chem, Lexington, KY 40506 USA

[4] Penn State Univ, Dept Chem, University Pk, PA 16802 USA

来源：

JOURNAL OF PHYSICAL CHEMISTRY LETTERS | 2016年 / 7卷 / 13期

基金：

美国国家科学基金会;

关键词：

CRYSTALLINE TETRACENE; ENERGY-TRANSFER; PENTACENE; DYNAMICS; STATES; KINETICS; FLUORESCENCE; SPECTROSCOPY; ANNIHILATION; DERIVATIVES;

D O I：

10.1021/acs.jpclett.6b00947

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Singlet fission is an excitation multiplication process in molecular systems that can circumvent energy losses and significantly boost solar cell efficiencies; however, the nature of a critical intermediate that enables singlet fission and details of its evolution into multiple product excitations remain obscure. We resolve the initial sequence of events comprising the fission of a singlet exciton in solids of pentacene derivatives using femtosecond transient absorption spectroscopy. We propose a three-step model of singlet fission that includes two triplet-pair intermediates and show how transient spectroscopy can distinguish initially interacting triplet pairs from those that are spatially separated and noninteracting. We find that the interconversion of these two triplet-pair intermediates is limited by the rate of triplet transfer. These results clearly highlight the classical kinetic model of singlet fission and expose subtle details that promise to aid in resolving problems associated with triplet extraction.

引用

页码：2370 / 2375

页数：6

共 40 条

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