Three-fold Symmetric Doping Mechanism in GaAs Nanowires.

Dastjerdi, M H T; Fiordaliso, E M; Leshchenko, E D; Akhtari-Zavareh, A; Kasama, T; Aagesen, M; Dubrovskii, V G; LaPierre, R R · Nano Lett · 2017

basic_science · Level V

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Abstract

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.