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HL: Halbleiterphysik

HL 9: Poster I

HL 9.48: Poster

Montag, 27. März 2006, 15:15–17:45, P3

Spontaneous 2D accumulation of charged Be dopants in GaAs p-n superlattices — •Sebastian Landrock, Knut Urban, and Philipp Ebert — Institut für Festkörperforschung, Forschungszentrum Jülich, 52425 Jülich

In a classical view abrupt dopant profiles in semiconductors tend to be smoothed out by diffusion due to concentration gradients and repulsive screened Coulomb interactions between the charged dopants. We demonstrate, however, using scanning tunneling microscopy and secondary ion mass spectroscopy, that charged Be dopant atoms in GaAs p-n superlattices spontaneously accumulate and form two-dimensional dopant layers. These are stabilized by reduced repulsive screened Coulomb interactions between the charged dopants arising from the two-dimensional quantum mechanical confinement of charge carriers.