title: Controlled Growth of Well-Defined Conjugated Polymers from the Surfaces of Multiwalled Carbon Nanotubes: Photoresponse Enhancement via Charge Separation.
abstract: The installation of heterojunctions on the surfaces of carbon nanotubes (CNTs) is an effective method for promoting the charge separation processes needed for CNT-based electronics and optoelectronics applications. Conjugated polymers are proven state-of-the-art candidates for modifying the surfaces of CNTs. However, all previous attempts to incorporate conjugated polymers to CNTs resulted in unordered interfaces. Herein we show that well-defined chains of regioregular poly(3-hexylthiophene) (P3HT) were successfully grown from the surfaces of multiwalled CNTs (MWNTs) using surface-initiated Kumada catalyst-transfer polycondensation. The polymerization was found to proceed in a controlled manner as chains of tunable lengths were prepared through variation of the initial monomer-to-initiator ratio. Moreover, it was determined that large-diameter MWNTs afforded highly ordered P3HT aggregates, which exhibited a markedly bathochromically shifted optical absorption due to a high grafting density induced planarization of the polymer chains. Using ultrafast spectroscopy, the heterojunctions formed between the MWNTs and P3HT were shown to effectively overcome the binding energy of excitons, leading to photoinduced electron transfer from P3HT to MWNTs. Finally, when used as prototype devices, the individual MWNT-g-P3HT core-shell structures exhibited excellent photoresponses under a low illumination density.
authors.affiliation: Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , 29 Zhongguancun East Road, Haidian District, Beijing 100190, China.
authors.forename: Wenpeng
authors.initials: W
authors.lastname: Hou
authors.affiliation: Department of Chemistry, Renmin University of China , Beijing 100872, China.
authors.forename: Ning-Jiu
authors.initials: NJ
authors.lastname: Zhao
authors.affiliation: Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS) , Ulsan 44919, Republic of Korea.
authors.forename: Dongli
authors.initials: D
authors.lastname: Meng
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Tang
authors.affiliation: Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , 29 Zhongguancun East Road, Haidian District, Beijing 100190, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zeng
authors.affiliation: Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , 29 Zhongguancun East Road, Haidian District, Beijing 100190, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , 29 Zhongguancun East Road, Haidian District, Beijing 100190, China.
authors.forename: Yangziwan
authors.initials: Y
authors.lastname: Weng
authors.affiliation: Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , 29 Zhongguancun East Road, Haidian District, Beijing 100190, China.
authors.forename: Chungui
authors.initials: C
authors.lastname: Cheng
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Xiulai
authors.initials: X
authors.lastname: Xu
authors.affiliation: Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , 29 Zhongguancun East Road, Haidian District, Beijing 100190, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Chemistry, Renmin University of China , Beijing 100872, China.
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Zhang
authors.affiliation: Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , 29 Zhongguancun East Road, Haidian District, Beijing 100190, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS) , Ulsan 44919, Republic of Korea.|Department of Chemistry and Department of Energy Engineering, Ulsan National Institute of Science and Technology (UNIST) , Ulsan 689-798, Republic of Korea.
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Bielawski
authors.affiliation: Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , 29 Zhongguancun East Road, Haidian District, Beijing 100190, China.
authors.forename: Jianxin
authors.initials: J
authors.lastname: Geng
keywords: carbon nanotubes; charge separation; photoresponse; poly(3-hexylthiophene); surface-initiated Kumada catalyst-transfer polycondensation