Dresden 2003 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

HL: Halbleiterphysik

HL 14: Poster I

HL 14.24: Poster

Montag, 24. März 2003, 17:00–19:30, HSZ/P2

Lattice Relaxation around Arsenic in Silicon and CdTe — •Vasil Koteski¹, Heinz Haas¹, Elisabeth Holub-Krappe¹, Nenad Ivanovic², and Heinz-Eberhard Mahnke¹ — ¹Hahn-Meitner-Institut Berlin, 14109 Berlin — ²Vinča Institute of Nuclear Science, POB 522, 11001 Belgrade, Yugoslavia

We have measured the lattice relaxation around As as dopant in Si and in CdTe with fluorescence detected EXAFS at HASYLAB. The experimental challenge lies in the necessary compromise between a concentration high enough for absorption and low enough to avoid compensation and clustering of the dopants. In the case of As in Si, special emphasis was given to reach a lower concentration than in earlier investigations. We complement our experimental work by ab-initio calculations based on density functional theory with the WIEN97 package using the LAPW method and with the FHI96md pseudo-potential program and find good convergence of the results with increasing size of the super-cells constructed around one substitutional As atom in Si. The calculations yield good agreement with our EXAFS experiment. In the case of As in CdTe, we could experimentally verify the lattice relaxation around the impurity atom as determined indirectly from calculations of the electric field gradient in comparison with the measured value in a PAC experiment (S. Lany et al., Phys. Rev. B 62, R2259 (2000)).