Mechanisms of droplet formation and Bi incorporation during molecular beam epitaxy of GaAsBi

Journal Article · Mon Jan 28 00:00:00 EST 2013 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4789369· OSTI ID:22162698

Vardar, G.; Warren, M. V.; Kang, M.; Jeon, S.; Goldman, R. S. ^[1]; Paleg, S. W. ^[2]

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1. Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)
2. Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130 (United States)

We have examined the mechanisms of droplet formation and Bi incorporation during molecular beam epitaxy of GaAsBi. We consider the role of the transition from group-V-rich to group-III-rich conditions, i.e., the stoichiometry threshold, in the presence of Bi. For As-rich GaAsBi growth, Bi acts as a surfactant, leading to the formation of droplet-free GaAsBi films. For films within 10% of the stoichiometric GaAsBi growth regime, surface Ga droplets are observed. However, for Ga-rich GaAsBi growth, Bi acts as an anti-surfactant, inducing Ga-Bi droplet formation. We propose a growth mechanism based upon the growth-rate-dependence of the stoichiometry threshold for GaAsBi.

• OSTI ID: 22162698
• Journal Information: Applied Physics Letters, Vol. 102, Issue 4; Other Information: (c) 2013 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BISMUTH COMPOUNDS
CRYSTAL GROWTH
DROPLETS
FILMS
GALLIUM ARSENIDES
LAYERS
MOLECULAR BEAM EPITAXY
SEMICONDUCTOR MATERIALS
STOICHIOMETRY
SURFACES
SURFACTANTS