Ultrafast dynamics of excitons in tetracene single crystals
Ultrafast dynamics of excitons in tetracene single crystals
复制标题
DOI：
10.1063/1.4867696
复制
发表时间：
2014-03-21
影响因子：
4.4
通讯作者：
Schwoerer, Heinrich
中科院分区：
文献类型：
--
作者：
Birech, Zephania;Schwoerer, Markus;Schwoerer, Heinrich
在室温下，通过可见光谱范围内的飞秒瞬态吸收光谱研究了独立式 200 nm 薄并四苯单晶中的超快激子动力学。单晶复杂的光谱重叠瞬态吸收迹线被系统地解卷积。由此，确定了基态、激发态和过渡态的超快动力学，包括单线态激子裂变成两个三线态激子。裂变是通过亚皮秒时间尺度上较高单线态 S-n 的直接裂变和 40 ps 时间尺度上单线态激子 S-1 的热激活裂变产生的。 S-1 激子的高能达维多夫分量预计会在亚皮秒时间尺度上发生裂变。在高密度三重态激子下，它们的相互湮灭（三重态-三重态湮灭）发生在 < 10 ps 的时间尺度上。 (C) 2014 AIP 出版有限责任公司。
Ultrafast exciton dynamics in free standing 200 nm thin tetracene single crystals were studied at room temperature by femtosecond transient absorption spectroscopy in the visible spectral range. The complex spectrally overlapping transient absorption traces of single crystals were systematically deconvoluted. From this, the ultrafast dynamics of the ground, excited, and transition states were identified including singlet exciton fission into two triplet excitons. Fission is generated through both, direct fission of higher singlet states S-n on a sub-picosecond timescale, and thermally activated fission of the singlet exciton S-1 on a 40 ps timescale. The high energy Davydov component of the S-1 exciton is proposed to undergo fission on a sub-picoseconds timescale. At high density of triplet excitons their mutual annihilation (triplet-triplet annihilation) occurs on a < 10 ps timescale. (C) 2014 AIP Publishing LLC.