| AVS 55th International Symposium & Exhibition | |
| Biological, Organic, and Soft Materials Focus Topic | Friday Sessions |
| Session BO+SS+AS-FrM |
| Session: | Self Assembled Ultrathin Organic Interfaces |
| Presenter: | A. Turchanin, University of Bielefeld, Germany |
| Authors: | A. Turchanin, University of Bielefeld, Germany D. Käfer, Ruhr-University Bochum, Germany M. El-Desawy, University of Bielefeld, Germany Ch. Wöll, Ruhr-University Bochum, Germany G. Witte, Ruhr-University Bochum, Germany A. Gölzhäuser, University of Bielefeld, Germany |
| Correspondent: | Click to Email |
Irradiation of aromatic self-assembled monolayers (SAMs) with low energy electrons1 or UV-light2 results in a lateral cross-linking and the formation of aromatic carbon nanosheets with a thickness of only one molecule. These films possess a high mechanical stability that allows their separation from the substrate and fabrication of free standing membranes with a thickness of ~1nm3 and exhibit further a remarkable thermal stability4 sustaining temperatures above 1000 K. Because of the promising potential of these ultrathin membranes for various applications in nano-devices, the knowledge of their molecular microstructure and the mechanisms of cross-linking are of great interest. We have employed a variety of in situ spectroscopic techniques including X-ray photoelectron spectroscopy (XPS), near edge X-ray absorption fine structure spectroscopy (NEXAFS), thermal desorption spectroscopy (TDS), and UV photoelectron spectroscopy (UPS) to characterize the electron irradiation of 1,1’-biphenyl-4-thiol (BPT) SAMs on Au. Experimental data are further compared with quantum chemical calculations of the electronic structure of cross-linked species, which allowed the identification of distinct molecular species leading to the formation of carbon nanosheets upon electron irradiation of BPT SAMs. Molecular mechanisms of the electron induced changes in aromatic SAMs will be discussed.
1Geyer, W.; Stadler, V.; Eck, W.; Zharnikov, M.; Gölzhäuser, A.; Grunze, M.; Appl. Phys. Lett. 75 (1999) 2401;
2Turchanin, A.; Schnietz, M.; El-Desawy, M.; Solak, H. H.; David, C.; Gölzhäuser, A.; Small 3 (2007) 2114.;
3Eck, W.; Küller, A.; Grunze, M.; Völkel, B.; Gölzhäuser, A.; Adv. Mater. 17 (2005) 2583.;
4Turchanin, A.; El-Desawy, M.; Gölzhäuser, A.; Appl. Phys. Lett. 90 (2007) 053102.