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HL: Halbleiterphysik

HL 4: Diamant

HL 4.1: Vortrag

Montag, 17. März 1997, 10:30–10:45, H3

Dotierung von Kohlenstoff Systemen – Eine Theoretische Untersuchung. — •P. Sitch., Th. K"ohler, G. Jungnickel, D. Porezag, and Th. Frauenheim — Instit"ut f"ur Physik, T. U. Chemnitz, D-09107, Chemnitz.

The problem of n– and p–doping of diamond and highly tetrahedral diamond-like amorphous carbon (ta–C) is one of immense technological significance. Diamond has been p–doped using Boron, but to date, no n–dopant has been found. For (ta–C), the ability of Boron and Nitrogen to dope is a subject of controversy amongst experimental workers, with some groups claiming to find doping [1], whilst others not [2].
We use a density functional–based tight–binding method (DF–TB) to investigate the effects of Boron and Nitrogen in diamond and ta–C. We explain why Boron dopes in diamond, but Nitrogen does not and also resolve the ta–C controversy, showing that both Nitrogen and Boron fail to dope due to charge transfer effects resulting from the presence of localized states associated with π clusters inherent in such systems.
We discuss also the possibility of n-type doping with Phosphorous and Arsenic.

[1] C. Ronning, U. Griesmeier, M. Gross, H. C. Hofsäss, R. G. Downing and G. P. Lamaze, Diamond and Related Materials 4, 666 (1995).

[2] V. S. Veerasamy, G. A. J. Amaratunga, C. A. Davies, A. E. Timbs, W. I. Milne, D. R. Mckenzie, J. Phys. Condens. Matter 5, L169 (1993).