Variation of lattice constant and cluster formation in GaAsBi

Puustinen J, Wu M, Luna E, Schramm A, Laukkanen P, Laitinen M, Sajavaara T, Guina M (2013)

Publication Language: English

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2013

Journal

Journal of Applied Physics AIP Publishing

Book Volume: 114

Article Number: 243504

Journal Issue: 24

DOI: 10.1063/1.4851036

Abstract

We investigate the structural properties of GaAsBi layers grown by molecular beam epitaxy on GaAs at substrate temperatures between 220-315 °C. Irrespective of the growth temperature, the structures exhibited similar Bi compositions, and good overall crystal quality as deduced from X-Ray diffraction measurements. After thermal annealing at temperatures as low as 500 °C, the GaAsBi layers grown at the lowest temperatures exhibited a significant reduction of the lattice constant. The lattice variation was significantly larger for Bi-containing samples than for Bi-free lowerature GaAs samples grown as a reference. Rutherford backscattering spectrometry gave no evidence of Bi diffusing out of the layer during annealing. However, dark-field and Z-contrast transmission electron microscopy analyses revealed the formation of GaAsBi clusters with a Bi content higher than in the surrounding matrix, as well as the presence of metallic As clusters. The apparent reduction of the lattice constant can be explained by a two-fold process: the diffusion of the excess As incorporated within As antisites to As clusters, and the reduction of the Bi content in the GaAs matrix due to diffusion of Bi to GaAsBi clusters. Diffusion of both As and Bi are believed to be assisted by the native point defects, which are present in the lowerature as-grown material. © 2013 AIP Publishing LLC.

Authors with CRIS profile

Mingjian Wu Lehrstuhl für Werkstoffwissenschaften (Mikro- und Nanostrukturforschung)

Additional Organisation(s)

Interdisziplinäres Zentrum, Center for Nanoanalysis and Electron Microscopy (CENEM)

Involved external institutions

Tampere University of Technology FI Finland (FI) University of Jyväskylä / Jyväskylän yliopisto FI Finland (FI) Paul-Drude-Institut für Festkörperelektronik - Leibniz-Institut im Forschungsverbund Berlin e.V. DE Germany (DE) University of Turku / Turun yliopisto FI Finland (FI)

How to cite

APA:

Puustinen, J., Wu, M., Luna, E., Schramm, A., Laukkanen, P., Laitinen, M.,... Guina, M. (2013). Variation of lattice constant and cluster formation in GaAsBi. Journal of Applied Physics, 114(24). https://doi.org/10.1063/1.4851036

MLA:

Puustinen, Janne, et al. "Variation of lattice constant and cluster formation in GaAsBi." Journal of Applied Physics 114.24 (2013).

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