Nano-thin films of Ge on GaAs: preparation and properties

V. F. Mitin, P. M. Lytvyn, V. V. Kholevchuk, L. A. Matveera, E. Yu. Kolyadina, E. F. Venger, Vlado Lazarov, Philip James Hasnip, I. E. Kotenko, V. V. Mitin

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We investigate the electronic, optical and structural properties of thin (100 nm) Ge films on GaAs(100) for a variety of growth rates. All of the films have a granular, single-crystal structure but the electronic properties vary dramatically, with resistivity and carrier concentration changing by more than three orders of magnitude. For high deposition rates the films are n-type, with relatively high carrier concentration and low resistivity. The temperature-dependence of the resistivity indicates metallic-like transport with degenerate charge carriers. For low deposition rates the films are p-type, with lower carrier
concentrations and higher resistivity whose temperature-dependence indicates semiconducting, activation-type transport. At moderate deposition rates a metal-insulator transition occurs. The electrical properties are analyzed in terms of the 2D percolation of charge carriers through a fluctuating electrostatic potential.
Original languageEnglish
Title of host publicationProceedings of the 2nd International Conference on Nanotechnology: Fundamentals and Applications
Pages283-1
Number of pages9
Publication statusPublished - Jul 2011

Keywords

  • Ge/GaAs, heterojunctions, thin Ge films, potential fluctuations, percolation.

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