Dresden 2006 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 3: III-V semiconductors I
HL 3.5: Vortrag
Montag, 27. März 2006, 11:15–11:30, POT 51
Agglomeration of As Antisites in As-rich LT-GaAs: Nucleation without a critical nucleus size — •Torsten E.M. Staab1, Risto M. Nieminen2, Martina Luysberg3, and Thomas Frauenheim4 — 1Helmholtz Institut für Strahlen- und Kernphysik,Rheinische Friedrich-Wilhelms-Universität Bonn, Nußallee 14-16,D-53115 Bonn, Germany — 2Laboratory of Physics, Helsinki University of Technology,P.O. Box 1100, FIN–02015 HUT, Finland — 3Institut für Festkörperforschung,Forschungszentrum Jülich, D–52425 Jülich, Germany — 4University GH Paderborn, Department of Physics, Theoretical Physics, D–33098 Paderborn, Germany
To investigate the early stages of nucleation and growth of As precipitations in GaAs grown at low substrate temperature (LT-GaAs) we make use of a self-consistent-charge density-functional based tight-binding method. Since already a pair of As-antisite shows a significant binding energy which increases when attaching more As-antisites, there is no critical nucleus size. Provided that all excess As has precipitated the clusters may grow in size since the binding energies increase with increasing agglomeration size. These findings close the gap between experimental investigation of point defects and the detection of nanometer-size precipitations in the TEM [1].
[1] T.E.M. Staab, R.M. Nieminen, M. Luysberg, and Th. Frauenheim, Phys. Rev. Lett. 95 (2005) 12550