Photoexcitation Dynamics in Films of C60 and Zn Phthalocyanine with a Layered Nanostructure
Photoexcitation Dynamics in Films of C60 and Zn Phthalocyanine with a Layered Nanostructure
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DOI：
10.1103/physrevlett.108.077402
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发表时间：
2012-02-15
影响因子：
8.6
通讯作者：
Heilweil, Edwin J.
中科院分区：
文献类型：
--
作者：
Lane, Paul A.;Cunningham, Paul D.;Heilweil, Edwin J.
利用瞬态吸收和时间分辨太赫兹光谱分析了C-60和酞菁锌（ZnPc）从皮秒到毫秒的光激发动力学。C-60的自电离是光载流子产生的前兆。太赫兹信号的衰减是由于前20 ps光载流子迁移率的下降，此后反映了复合动力学。通过模拟C-60激发后ZnPc吸收基态漂白的上升，确定了C-60中的单线态扩散速率。随着层厚的减小，复合动力学从双分子转变为单分子，在C-60/ZnPc界面处形成亚稳态杂络合物，其寿命为150 μ s。
We elucidate photoexcitation dynamics in C-60 and zinc phthalocyanine (ZnPc) from picoseconds to milliseconds by transient absorption and time-resolved terahertz spectroscopy. Autoionization of C-60 is a precursor to photocarrier generation. Decay of the terahertz signal is due to decreasing photocarrier mobility over the first 20 ps and thereafter reflects recombination dynamics. Singlet diffusion rates in C-60 are determined by modeling the rise of ground state bleaching of ZnPc absorption following C-60 excitation. Recombination dynamics transform from bimolecular to monomolecular as the layer thickness is reduced, revealing a metastable exciplex at the C-60/ZnPc interface with a lifetime of 150 mu s.