Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 15 December 2006:
Vol. 314. no. 5806, pp. 1761 - 1764
DOI: 10.1126/science.1134441
Prev | Table of Contents | Next

Reports

Photoconductive Coaxial Nanotubes of Molecularly Connected Electron Donor and Acceptor Layers

Yohei Yamamoto,1 Takanori Fukushima,1,2* Yuki Suna,1 Noriyuki Ishii,3 Akinori Saeki,4 Shu Seki,4 Seiichi Tagawa,4 Masateru Taniguchi,4 Tomoji Kawai,4 Takuzo Aida1,2*

Controlled self-assembly of a trinitrofluorenone-appended gemini-shaped amphiphilic hexabenzocoronene selectively formed nanotubes or microfibers with different photochemical properties. In these nanotubes, which are 16 nanometers in diameter and several micrometers long, a molecular layer of electron-accepting trinitrofluorenone laminates an electron-donating graphitic layer of {pi}-stacked hexabenzocoronene. The coaxial nanotubular structure allows photochemical generation of spatially separated charge carriers and a quick photoconductive response with a large on/off ratio greater than 104. In sharp contrast, the microfibers consist of a charge-transfer complex between the hexabenzocoronene and trinitrofluorenone parts and exhibit almost no photocurrent generation.

1 Aida Nanospace Project, Exploratory Research for Advanced Technology–Solution Oriented Research for Science and Technology (ERATO-SORST), Japan Science and Technology Agency, National Museum of Emerging Science and Innovation, 2-41 Aomi, Koto-ku, Tokyo 135–0064, Japan.
2 Department of Chemistry and Biotechnology, School of Engineering, and Center for NanoBio Integration, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113–8656, Japan.
3 Biological Information Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba Central-6, 1-1-1 Higashi, Tsukuba, Ibaraki 305–8566, Japan.
4 Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567–0047, Japan.

* To whom correspondence should be addressed. E-mail: fukushima{at}nanospace.miraikan.jst.go.jp (T.F.); aida{at}macro.t.u-tokyo.ac.jp (T.A.)

Read the Full Text

To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)