Berlin 2012 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 45: Correlated Electrons: Poster Session

TT 45.58: Poster

Thursday, March 29, 2012, 15:00–19:00, Poster B

Band structure engineering and vacancy induced metallicity at the GaAs-AlAs interface — •Mousumi Upadhyay Kahaly, Safdar Nazir, and Udo Schwingenschlögl — KAUST, PSE Division, Thuwal 23955-6900, Kingdom of Saudi Arabia

We study the epitaxial GaAs-AlAs interface of wide gap materials by means of full-potential density functional theory based calculations. We find an insulating state at the interface and a negligible charge transfer. Optimization of the atomic positions results in very small changes in the chemical bonding. We aim to understand how an anionic defect at and near the interface modifies the electronic structure and therefore the physical properties of the GaAs-AlAs heterostructure. Introduction of As vacancies near the interface induces metallicity, which opens great potential for GaAs-AlAs heterostructures in modern electronics. While GaAs and AlAs are known since long to form high quality epitaxial superlattices, the effect of n-doping on the electronic properties of this heterostructure has been ignored so far. The systems under investigation are suitable for disentangling the complex behavior of metallic interface states.