Use of Side‐Chain Incompatibility for Tailoring Long‐Range p/n Heterojunctions: Photoconductive Nanofibers Formed by Self‐Assembly of an Amphiphilic Donor–Acceptor Dyad Consisting of Oligothiophene and Perylenediimide |
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| Authors: | Wei‐Shi Li Prof. Dr. Akinori Saeki Dr. Yohei Yamamoto Dr. Takanori Fukushima Dr. Shu Seki Prof. Dr. Noriyuki Ishii Dr. Kenichi Kato Dr. Masaki Takata Prof. Dr. Takuzo Aida Prof. Dr. |
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| Affiliation: | 1. Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Ling‐Ling Road, Shanghai 200032 (China), Fax: (+86)?21‐5492‐5381;2. Graduate School of Engineering, Osaka University and PRESTO, Japan Science and Technology Agency (JST), 2‐1 Yamadaoka, Suita, Osaka 565‐0871(Japan);3. ERATO‐SORST Nanospace Project, Japan Science and Technology Agency (JST), National Museum of Emerging Science and Innovation, 2‐3‐6 Aomi, Koto‐ku, Tokyo 135‐0064 (Japan), Fax: (+81)?3‐5841‐7310;4. Advanced Science Institute, RIKEN, 2‐1 Hirosawa, Wako, Saitama 351‐0198 (Japan), Fax: (+81)?48‐467‐8214;5. National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central‐6, 1‐1‐1 Higashi, Tsukuba, Ibaraki 305‐8566 (Japan);6. RIKEN SPring‐8 Center, 1‐1‐1 Kouto, Sayo‐cho, Sayo‐gun, Hyogo 679‐5148 (Japan) |
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| Abstract: | To tailor organic p/n heterojunctions with molecular‐level precision, a rational design strategy using side‐chain incompatibility of a covalently connected donor–acceptor (D–A) dyad has been successfully carried out. An oligothiophene–perylenediimide dyad, when modified with triethylene glycol side chains at one terminus and dodecyl side chains at the other ( 2 Amphi ), self‐assembles into nanofibers with a long‐range D/A heterojunction. In contrast, when the dyad is modified with dodecyl side chains at both termini ( 2 Lipo ), ill‐defined microfibers result. In steady‐state measurements using microgap electrodes, a cast film of the nanofiber of 2 Amphi displays far better photoconducting properties than that of the microfiber of 2 Lipo . Flash‐photolysis time‐resolved microwave conductivity measurements, in conjunction with transient absorption spectroscopy, clearly indicate that the nanofiber of 2 Amphi intrinsically allows for better carrier generation and transport properties than the microfibrous assembly of 2 Lipo . |
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| Keywords: | amphiphiles heterojunctions nanostructures photoconduction self‐assembly |
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