First Principles Probing of Photo-Generated Intermolecular Charge Transfer State in Conjugated Oligomers

作     者：Ding-hao Hong Li Chen Qing-gangKong Hui Cao 洪顶豪;陈力;孔庆刚;曹晖

作者机构：Jiang Su Laboratory of Atmospheric Environment Monitoring and Pollution Control Collaborative Cen- ter of Atmospheric Environment and Equipment Technology School of Environmental Science and Engineering Nanjing University of Information Science and Technology Nanjing 210044 China 

出 版 物：《Chinese Journal of Chemical Physics》 (化学物理学报（英文）)

年 卷 期：2018年第31卷第2期

页      面：171-176,245页

核心收录：

学科分类：081704[工学-应用化学] 070207[理学-光学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 070305[理学-高分子化学与物理] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0803[工学-光学工程] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China (No.21473092) the Jiangsu Province Production and Joint Innovation Fund-Prospective Joint Research Project (No. BY2014007-01) 

主　　题：CPDTBT Charge transfer state Charge separation 

摘      要：We perform density functional theory calculations to investigate the polaron pair （charge transfer state） photo-generation in donor-acceptor oligomer methyl-capped （4,7- benzo[2,1,3]thiadiazole-2,6-（4,4-bis（2-ethylhexyl）-4H-cyclopent a[1,2-b;3,4-b＇]dithiophene-4, 7-benzo[2,1,3]thiadiazole） （CPDTBT）. Results show that effective photo-generation of charge transfer state can happen in CPDTBT dimer when the group 4,7-benzo[2,1,3]thiadiazole （BT） in one monomer deviates against the conjugated plane （onset torsion angle is about 20°）. The lower excitation energy （530 nm） can only generate the intramolecular excitonic state, while the higher excitation energy （370 nm） can generate the intermolecular charge transfer state, in good agreement with the experiment. Moreover, the mechanism of charge separation in CPDTBT oligorners is discussed.