Document Type

Journal Article

Department/ Unit

Institute of Computational and Theoretical Studies

Abstract

Oxygen vacancies (VO) are known to be common native defects in zinc oxide (ZnO) and to play important roles in many applications. Based on density functional theory, we present a study for the migration of oxygen vacancies in ultra-thin ZnO nanowires (NWs). We find that under equilibrium growth conditions VO has a higher formation energy (Ef) inside the wire than that at shallow sites and surface sites, with different geometric relaxations and structural reconstructions. The migration of VO has lower barriers in the NW than in the bulk and is found to be energetically favorable in the direction from the bulk to the surface. These results imply a higher concentration of VO at surface sites and also a relative ease of diffusion in the NW structure. Our results support the previous experimental observations and are important for the development of ZnO-based devices in photocatalysis and optoelectronics.

Publication Year

2014

Journal Title

Nanoscale

Volume number

6

Issue number

20

Publisher

Royal Society of Chemistry

First Page (page number)

11882

Last Page (page number)

11886

Referreed

1

DOI

10.1039/C4NR03582H

ISSN (print)

20403372

Included in

Physics Commons

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