Regensburg 2004 – scientific programme

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HL: Halbleiterphysik

HL 12: Poster I

HL 12.59: Poster

Monday, March 8, 2004, 16:30–19:00, Poster A

Investigation of Experimentally Observed InAs Quantum Dots with an Analytical Bond-Order Potential — •Thomas Hammerschmidt and Peter Kratzer — Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin

A thorough understanding of the experimentally observed shape of InAs quantum dots (QD) calls for non-equilibrium simulations that take kinetic growth-effects into account. The modeling of such effects requires large system sizes and long simulation times.

We address this issue with a new analytical bond-order potential of the Abell-Tersoff type for InGaAs that was derived from previously published potentials. We optimized the new potential for reconstructions of the GaAs (001) surface with preserving the previous adoptions to GaAs bulk phases. Furthermore, we adjusted the potential to capture different In and InAs bulk phases, as well as InAs surfaces, more accurately.

With the new potential we determined the potential energy surface and various diffusion barriers on high-index surfaces and compare with density functional calculations. Additionally we relaxed uncapped InAs QD in different experimentally observed shapes and investigate strain effects.