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Defect Dynamics in Self-Catalyzed III-V Semiconductor Nanowires

Gott, JA; Beanland, R; Fonseka, HA; Peters, JJP; Zhang, Y; Liu, H; Sanchez, AM; (2019) Defect Dynamics in Self-Catalyzed III-V Semiconductor Nanowires. Nano Letters , 19 (7) pp. 4574-4580. 10.1021/acs.nanolett.9b01508. Green open access

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Abstract

The droplet consumption step in self-catalyzed III–V semiconductor nanowires can produce material that contains a high density of line defects. Interestingly, these defects are often associated with twin boundaries and have null Burgers vector, i.e., no long-range strain field. Here, we analyze their stability by considering the forces that act on them and use in situ aberration corrected scanning transmission electron microscopy (STEM) to observe their behavior in GaAsP nanowires (NWs) using short annealing cycles. Their movement appears to be consistent with the thermally activated single- or double-kink mechanisms of dislocation glide, with velocities that do not exceed 1 nm s–1. We find that motion of individual defects depends on their size, position, and surrounding environment and set an upper limit to activation energy around 2 eV. The majority of defects (>70%) are removed by our postgrowth annealing for several seconds at temperatures in excess of 640 °C, suggesting that in situ annealing during growth at lower temperatures would significantly improve material quality. The remaining defects do not move at all and are thermodynamically stable in the nanowire.

Type: Article
Title: Defect Dynamics in Self-Catalyzed III-V Semiconductor Nanowires
Open access status: An open access version is available from UCL Discovery
DOI: 10.1021/acs.nanolett.9b01508
Publisher version: https://doi.org/10.1021/acs.nanolett.9b01508
Additional information: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
Keywords: Defects, In-Situ, Nanowires, STEM, TEM
UCL classification: UCL
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Electronic and Electrical Eng
URI: https://discovery.ucl.ac.uk/id/eprint/10080694
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