Impact of Electron Delocalization on the Nature of the Charge-Transfer States in Model Pentacene/C60 Interfaces: A Density Functional Theory Study
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- 作者：Bing Yang ; Yuanping Yi ; Cai-Rong Zhang ; Saadullah G. Aziz ; Veaceslav Coropceanu ; Jean-Luc Br茅das
- 刊名：Journal of Physical Chemistry C
- 出版年：2014
- 出版时间：December 4, 2014
- 年：2014
- 卷：118
- 期：48
- 页码：27648-27656
- 全文大小：619K
- ISSN：1932-7455
文摘
Electronic delocalization effects have been proposed to play a key role in photocurrent generation in organic photovoltaic devices. Here, we study the role of charge delocalization on the nature of the charge-transfer (CT) states in the case of model complexes consisting of several pentacene molecules and one fullerene (C60) molecule, which are representative of donor/acceptor heterojunctions. The energies of the CT states are examined by means of time-dependent density functional theory (TD-DFT) using the long-range-corrected functional, 蠅B97X, with an optimized range-separation parameter, 蠅. We provide a general description of how the nature of the CT states is impacted by molecular packing (i.e., interfacial donor/acceptor orientations), system size, and intermolecular interactions, features of importance in the understanding of the charge-separation mechanism.