Pristine nanostructures
Fullerenes and nanotubes are the third stable allotrope of carbon (besides graphite and diamond) and were first discovered in molecular beam experiments in 1985. This won the team of scientists involved the 1996 Nobel prize in chemistry for the discovery of C60 . (Harold W. Kroto, Robert F. Curl and Richard E. Smalley). Nanotubes were first discovered by Ijiima in an transmission electron microscope in 1991.
Carbon nanostructures come in all shapes and sizes, from the famous football-shaped C60 pictured above to monster fullerenes and nanotubes containing thousands of carbon atoms. Due to their fascinating electronic and mechanical properties these carbon nanostructures promise applications for nanoelectronics and nanoengineering, e.g. as molecular transistors, field emitters and STM tips. Especially, the electronic properties of single wall carbon nanotubes vary depend on the wrapping angle and diameter of the graphene sheet giving either metallic or semiconducting behavior. Hence, carbon nanostructures could serve as ideal building blocks for future bottom-up electronics.
We've been busy studying pristine fullerenes and nanotubes to understand which parameters control their electronic structure before one starts to engineer their properties by doping. Some of the highlights of this work include studies of :
Pristine fullerenes:
- Using EELS and PES to analyze the electronic structure of higher fullerenes as a function of cage symmetry. Different configuration of the five membered rings at the cage leads to strong differences in the electronic band structure.
Pristine single wall carbon nanotubes (SWCNT):
- Analysis of the production conditions by laser ablation:
SWCNT yield, mean diameter and diameter distribution as function of T, gas, pressure, catalyst particles, laser puls, ....
- Purification of SWCNT:
We are busy in purification by an effective removal of metal particles and amorphous carbon species of SWCNT by acid treatments, selective oxidation, and cross flow filtration. Some results are shown in the TEM pictures below.
Electronic properties of SWCNT from EELS and optical absorption:
We have been busy investigating the special features of these one-dimensional objects and to find out the character of the interband and collective electronic exitations in different types of single- and multi-wall carbon nanotubes.
Other carbon nanostructures:
- Analysis of the electronic properties of multi wall carbon nanotubes.
- Analysis of the electronic properties carbon onions.
Below are listed some of the papers which have resulted from our work on pristine carbon nanostructures. If you'd like a copy of any of these or more information, then please contact Thomas Pichler.
Literature:
- M. H. Rümmeli, E. Borowiak-Palen, T. Gemming, T. Pichler, M. Knupfer, M. Kalbác, L. Dunsch, O. Jost, S. R. P. Silva, W. Pompe, B. Büchner
Novel catalysts, room temperature and the importance of oxygen for the synthesis of single wall carbon nanotubes.
Nano Letters, Vol. 5, Nr. 7, (2005) S. 1209-121512 - C. Kramberger, A. Waske, K. Biedermann, T. Pichler, T. Gemming, B. Buechner, H. Kataura
Tailoring carbon nanostructures via temperature and laser irradiation
Chemical Physics Letters 407 (2005), S. 254-259 - B. Bendjemil, E. Borowiak-Palen, A. Graff, T. Pichler, M. Guerioune, J. Fink, M. Knupfer
Elimination of metal catalyst and carbon-like impurities from single-wall carbon nanotube raw material
Appl. Phys. A 78, 311–314 (2004)
- R. Pfeiffer, H. Kuzmany, C. Kramberger, C. Schaman, T. Pichler, H. Kataura, Y. Achiba, J. Kuerti, V. Zolyomi
Unusual high degree of unperturbed environment in the interior of single-wall carbon nanotubes
Physical Review Letters 90 (2003), 225501 - A.G. Marinopoulos, L. Reining, V. Olevano, A. Rubio, T. Pichler, X. Liu, M. Knupfer and J. Fink
Anisotropy and interplane interactions in the dielectric response of graphite
Phys. Rev. Lett. 89, 076402 (2002) - E. Borowiak-Palen, T. Pichler, X. Liu, M. Knupfer, A. Graff, O. Jost, W. Pompe, R.J. Kalenczuk, J. Fink
Reduced diameter distribution of single-wall carbon nanotubes by selective oxidation
Chem. Phys. Lett. 363 (2002) Nr. 5-6, S. 567-572 - R. Pfeiffer, H. Kuzmany, W. Plank, T. Pichler, H. Kataura, Y. Achiba
Spectroscopic analysis of single-wall carbon nanotubes and carbon nanotube peapods
Diamond and Related Materials 11 (2002) Nr. 3-6, S. 957-960 - O. Jost, A.A. Gorbunov, J. Moeller, W. Pompe, X. Liu, P. Georgi, L. Dunsch, M.S. Golden, J. Fink
Rate-limiting processes in the formation of single-wall carbon nanotubes: Pointing the way to the nanotube formation mechanism
Journal of Physical Chemistry B 106 (2002) Nr. 11, S. 2875-2883 - X. Liu, T. Pichler, M. Knupfer, M.S. Golden, J. Fink, H. Kataura and Y. Achiba
Detailed analysis of the mean diameter and diameter distribution of single wall carbon nanotubes from their optical response
Phys. Rev. B 66, 045411 (2002) - T. Pichler, M. Knupfer, M. S. Golden, J. Fink, T. Cabioc'h
Electronic structure and optical properties of concentric-shell fullerenes from electron energy-loss spectroscopy in transmission
Phys. Rev. B 63, 155415 (2001) - X. Liu, T. Pichler, M. Knupfer, M. S. Golden, J. Fink, D. A. Walters, M. J. Casavent, J. Schmidt, R. E. Smalley
An electron energy-loss study of the structural and electronic properties of magnetically aligned single-walled carbon nanotubes
Synth. Metals, 121, 1183 (2001) - H. Kuzmany, W. Plank, M. Hulman, Ch. Kramberger, A. Grueneis, Th. Pichler, H. Peterlik, H. Kataura, Y. Achiba
Determination of SWCNT diameters from the Raman response of the radial breathing mode
European Physical Journal B 22 (2001) Nr. 3, S. 307-320 - T. Pichler
Electron energy-loss studies of pristine and doped nanotubes, New Diamond and Frontier Carbon
Technology 11 (2001) Nr. 6, S. 375-397 - O. Jost, A. A. Gorbunov, J. Möller, W. Pompe, A. Graff, R. Friedlein, X. Liu, M. S. Golden, J. Fink
Impact of catalyst coarsening on the formation of single-wall carbon nanotubes
Chem. Phys. Lett, 339, 297-304 (2001) - M. Knupfer
Electronic properties of carbon nanostructures
Surface Science Reports 42, 1 (2001) - A. A. Gorbunov, R. Friedlein, O. Jost, M.S. Golden, J. Fink and W. Pompe
Gas dynamic consideration of the laser evaporation synthesis of single-wall carbon nanotubes
Appl. Phys. A 69, S593 (1999) - O. Jost, A. A. Gorbunov, W. Pompe, T. Pichler, R. Friedlein, M. Knupfer, M. Reibold, H.-D. Bauer, L. Dunsch, M. S. Golden and J. Fink
Diameter grouping of bulk samples of single-walled carbon nanotubes from optical absorption spectroscopy
Appl. Phys. Lett., 75, 2217 (1999) - M. Knupfer, T. Pichler, M.S. Golden, J. Fink, A. Rinzler, and R.E. Smalley
Electron energy-loss spectroscopy studies of single wall carbon nanotubes
Carbon 37, 733 (1999) - T. Pichler, M. Knupfer, M.S. Golden, J. Fink, A. Rinzler, and R.E. Smalley
The loss function and optical conductivity of polassium intercalated bundles of single wall carbon nanotubes
Synth. Metals 103, 2515 (1999) - M. Knupfer, O. Knauff, M. S. Golden, J. Fink, M. Bürk, D. Fuchs, S. Schuppler, R. H. Michels, and M. M. Kappes
Electronic structure of the two C78 isomers with C2v symmetry
Chem. Phys. Lett. 258 (1996) 513 - M. S. Golden, M. Knupfer, J. Fink, J. F. Armbruster, T. R. Cummins, H. A. Romberg, M. Roth, M. Sing, M. Schmidt, E. Sohmen
The electronic structure of fullerenes and fullerene compounds from high-energy spectroscopy
[this paper gives an overview of our work in the filed up to 1994]
J. Phys. Cond. Matter 7 (1995) 8219. - H. A. Romberg, M. Knupfer, J. F. Armbruster, and G. Roth
Electronic structure of C70 and C70(S8)6 studied using electron energy-loss spectroscopy
Synthetic Metals 70 (1995) 1379 - J. F. Armbruster, M. Roth, H. A. Romberg, M. Sing, M. Schmidt, P. Schweiss, P. Adelmann, M. S. Golden, J. Fink, R. H. Michel, J. Rockenberger, F. Hennrich, and M. M. Kappes
Electron energy-loss and photoemission studies of solid C84
Phys. Rev. B 50 (1994) 4933 - J. F. Armbruster, H. A. Romberg, P. Schweiss, P. Adelmann, M. Knupfer, J. Fink, R. H. Michel, J. Rockenberger, F. Hennrich, H. Schreiber, and M. M. Kappes
Crystal and electronic structure of solid C76
Z. Phys. B 95 (1994) 469 - E. Sohmen, J. Fink, R. H. Baughman and W. Krätschmer
Electron energy-loss spectroscopy studies on C60 and C70 fullerite
Z. Phys. B, 86 (1992) 87
IFF / Electronic and optical Properties || Last update 5. December 2006 || Author: T. Pichler