Polarity determination of crystal defects in zincblende GaN by aberration-corrected electron microscopy

Xiu, Huixin, Fairclough, Simon M., Gundimeda, Abhiram, Kappers, Menno J., Wallis, David J. ORCID: https://orcid.org/0000-0002-0475-7583, Oliver, Rachel A. and Frentrup, Martin 2023. Polarity determination of crystal defects in zincblende GaN by aberration-corrected electron microscopy. Journal of Applied Physics 133 , 105302. 10.1063/5.0138478

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Abstract

Aberration-corrected scanning transmission electron microscopy techniques are used to study the bonding configuration between gallium cations and nitrogen anions at defects in metalorganic vapor-phase epitaxy-grown cubic zincblende GaN on vicinal (001) 3C-SiC/Si. By combining high-angle annular dark-field and annular bright-field imaging, the orientation and bond polarity of planar defects, such as stacking faults and wurtzite inclusions, were identified. It is found that the substrate miscut direction toward one of the 3C-SiC ⟨110⟩ in-plane directions is correlated with the crystallographic [1–10] in-plane direction and that the {111} planes with a zone axis parallel to the miscut have a Ga-polar character, whereas the {111} planes in the zone perpendicular to the miscut direction have N-polarity. The polarity of {111}-type stacking faults is maintained in the former case by rotating the coordination of Ga atoms by 180° around the ⟨111⟩ polar axes and in the latter case by a similar rotation of the coordination of the N atoms. The presence of small amounts of the hexagonal wurtzite phase on Ga-polar {111} planes and their total absence on N-polar {111} planes is tentatively explained by the preferential growth of wurtzite GaN in the [0001] Ga-polar direction under non-optimized growth conditions. I. INTRODUCTION

Item Type:	Article
Date Type:	Published Online
Status:	Published
Schools:	Engineering
Publisher:	American Institute of Physics
ISSN:	0021-8979
Date of First Compliant Deposit:	10 March 2023
Date of Acceptance:	20 February 2023
Last Modified:	04 May 2023 05:36
URI:	https://orca.cardiff.ac.uk/id/eprint/157653

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