Three-fold Symmetric Doping Mechanism in GaAs Nanowires

• Published in: Nano letters Vol. 17; no. 10; pp. 5875 - 5882
• Main Authors: Dastjerdi, M. H. T, Fiordaliso, E. M, Leshchenko, E. D, Akhtari-Zavareh, A, Kasama, T, Aagesen, M, Dubrovskii, V. G, LaPierre, R. R
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 11-10-2017
• Subjects: gallium arsenide; molecular beam epitaxy; nanowires; self-assisted; doping; beryllium; GaAs
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.7b00794

A new dopant incorporation mechanism in Ga-assisted GaAs nanowires grown by molecular beam epitaxy is reported. Off-axis electron holography revealed that p-type Be dopants introduced in situ during molecular beam epitaxy growth of the nanowires were distributed inhomogeneously in the nanowire cross-section, perpendicular to the growth direction. The active dopants showed a remarkable azimuthal distribution along the (111)B flat top of the nanowires, which is attributed to preferred incorporation along 3-fold symmetric truncated facets under the Ga droplet. A diffusion model is presented to explain the unique radial and azimuthal variation of the active dopants in the GaAs nanowires.