Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-19T02:08:26.619Z Has data issue: false hasContentIssue false
  • English
  • Français

Radiotracer Diffusion Measurements of Noble Metal Atoms in Semiconducting Organic Films.

Published online by Cambridge University Press:  01 February 2011

Michael Scharnberg ,
Jörn Kanzow ,
Klaus Rätzke ,
Rainer Adelung ,
Franz Faupel ,
Stephan Meyer  and
Jens Pflaum
Michael Scharnberg
Affiliation:
Chair for Multicomponent Materials, CAU Kiel, Kaiserstrasse 2, 24143 Kiel, Germany
Jörn Kanzow
Affiliation:
Chair for Multicomponent Materials, CAU Kiel, Kaiserstrasse 2, 24143 Kiel, Germany
Klaus Rätzke
Affiliation:
Chair for Multicomponent Materials, CAU Kiel, Kaiserstrasse 2, 24143 Kiel, Germany
Rainer Adelung
Affiliation:
Chair for Multicomponent Materials, CAU Kiel, Kaiserstrasse 2, 24143 Kiel, Germany
Franz Faupel
Affiliation:
Chair for Multicomponent Materials, CAU Kiel, Kaiserstrasse 2, 24143 Kiel, Germany
Stephan Meyer
Affiliation:
3. Physikalisches Institut, University Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
Jens Pflaum
Affiliation:
3. Physikalisches Institut, University Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
Get access

Abstract

The application of organic field effect transistors (OFETs) for large scale low-cost electronic devices has lead to intense research. Diindenoperylene (DIP) thin films on SiO2 are a prominent system due to their high structural out-of-plane order. While bottom contact OFET structures can be realized easily, preparation of top contacts might cause diffusion of metal atoms (typically Ag or Au) deep into the organic film changing the injection properties at the interface. These properties are of great importance for device fabrication. Therefore, only by understanding the diffusion behaviour of metals into the organic layer, formation of well defined interfaces and control of their properties will become possible. For a better understanding of the diffusion of noble metal atoms into crystalline organic films, a radiotracer technique has been used to obtain diffusion profiles for Ag and Au diffusion in crystalline DIP films. For Ag diffusion in DIP, the decrease in Ag concentration of four orders of magnitude within the first few nanometers indicates that most of the metal atoms remain near the surface while small amounts can penetrate deep into the thin film and can even accumulate at the interface between organic film and the silicon substrate. A comparison with diffusion profiles obtained for polymers indicates that the interplay between diffusion and immobilization by aggregation also determine the diffusion behaviour of metals in organic crystalline materials. Latest experiments support this interpretation of the diffusion profiles. Single atoms are highly mobile in the organic crystalline material due to the weak interaction between the metal and the organic material. Therefore, most of the single atoms that penetrate into the material do so during the initial phase of the deposition. When more and more atoms arrive at the surface, cluster formation sets in. Due to the high cohesive energy of the metal the atoms can not leave the cluster and become immobilized. After deposition of a closed surface layer no further metal diffusion should be observed. With the knowledge about the diffusion processes gained by the radiotracer measurements control of process parameters and development of barrier layers in sub-monolayer range should be possible.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 871: Symposium I – Organic Thin-Film Electronics , 2005 , I6.31
Copyright
Copyright © Materials Research Society 2005

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Gupta, D. and Tsui, R.T.C., Appl. Phys. Lett. 17, 7, 294–297 (1970).Google Scholar
2 Faupel, F., Gupta, D., Silverman, B. D., and Ho, P. S., Appl. Phys. Lett. 55, 357 (1989).Google Scholar
3 Faupel, F., Willecke, R., and Thran, A., Mater. Sci. Eng. R 22, 1 (1998), invited reviewGoogle Scholar
4 Faupel, F., Thran, A., Zaporojtchenko, V., Strunskus, T., and Kiene, M., in Advanced Technological Materials, edited by Gupta, D., (Noyes Publication, William Andrew Publishing, LLC, 2004).Google Scholar
5 Dimitrakopoulos, C.D. and Malenfant, P.R.L., Adv. Mater. 14, 99, (2002).Google Scholar
6 Ishii, H. Hayashi, N., and Seki, K., Conjugated Polymer and Molecular Interfaces, edited by. Salaneck, W.R., Seki, K., Khan, A., and Pireaux, J.J., (M. Dekker, New York 2002), Chap. 10.Google Scholar
7 Horowitz, G., Adv. Mater. 10, 365 (1998).Google Scholar
8 Koch, N. et al., in Conjugated Polymer and Molecular Interfaces, edited by Salaneck, W.R. et al., (M. Dekker, New York, 2002).Google Scholar
9 Shen, C., Kahn, A. and Hill, I.G., in Conjugated Polymer and Molecular Interfaces, edited by Salaneck, W.R., Seki, K., Khan, A., and Pireaux, J.J. (M. Dekker, New York, 2002) Chap. 11.Google Scholar
10 Dürr, A. C., Koch, N., Kelsch, M., Rühm, A., Ghijsen, J., Johnson, R. L., Pireaux, J.-J., Schwartz, J., Dosch, H., and Kahn, A., Phys. Rev. B, 68, 115428, (2003).Google Scholar
11 Dürr, A. C., Schreiber, F., Kelsch, M., Carstanjen, H. D., and Dosch, H., Adv. Mater. 14, 961, (2002).Google Scholar
12 Thran, A., Strunskus, T., Zaporojtchenko, V., and Faupel, F., Appl. Phys. Lett. 81, 2, 244 (2002).Google Scholar
13 Karl, N., in Organic Electronic Materials, Part II: Low Molecular Weight Organic Solids, edited by Farchioni, R. and Grosso, G. (Springer Verlag, Berlin, 2001), Chap. 3.Google Scholar
14 Willecke, R., Faupel, F., Macromolecules 30, 567 (1997).Google Scholar
15 LeGoues, F. K., Silverman, B. D., and Ho, P. S. J. Vac. Sci. Technol. A 6, 2200–2204 (1988).Google Scholar