Atomic-resolution spectrum imaging of semiconductor nanowires

Zamani, R. R., Hage, F. S., Lehmann, S., Ramasse, Q. M. and Dick, K. A. (2018) Atomic-resolution spectrum imaging of semiconductor nanowires. Nano Letters, 18(3), pp. 1557-1563. (doi: 10.1021/acs.nanolett.7b03929) (PMID:29116807)

Abstract

Over the past decade, III–V heterostructure nanowires have attracted a surge of attention for their application in novel semiconductor devices such as tunneling field-effect transistors (TFETs). The functionality of such devices critically depends on the specific atomic arrangement at the semiconductor heterointerfaces. However, most of the currently available characterization techniques lack sufficient spatial resolution to provide local information on the atomic structure and composition of these interfaces. Atomic-resolution spectrum imaging by means of electron energy-loss spectroscopy (EELS) in the scanning transmission electron microscope (STEM) is a powerful technique with the potential to resolve structure and chemical composition with sub-angstrom spatial resolution and to provide localized information about the physical properties of the material at the atomic scale. Here, we demonstrate the use of atomic-resolution EELS to understand the interface atomic arrangement in three-dimensional heterostructures in semiconductor nanowires. We observed that the radial interfaces of GaSb–InAs heterostructure nanowires are atomically abrupt, while the axial interface in contrast consists of an interfacial region where intermixing of the two compounds occurs over an extended spatial region. The local atomic configuration affects the band alignment at the interface and, hence, the charge transport properties of devices such as GaSb–InAs nanowire TFETs. STEM–EELS thus represents a very promising technique for understanding nanowire physical properties, such as differing electrical behavior across the radial and axial heterointerfaces of GaSb–InAs nanowires for TFET applications.

• Item Type: Articles
• Additional Information: This work was financially supported by the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC grant agreement no. 336126; the Swedish Research Council (VR); the Knut and Alice Wallenberg Foundation (KAW); and UK Engineering and Physical Sciences Research Council (EPSRC).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hage, Dr Fredrik Sydow
• Authors: Zamani, R. R., Hage, F. S., Lehmann, S., Ramasse, Q. M., and Dick, K. A.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Nano Letters
• Publisher: American Chemical Society
• ISSN: 1530-6984
• ISSN (Online): 1530-6992
• Published Online: 08 November 2017
• Copyright Holders: Copyright © 2017 American Chemical Society
• First Published: First published in Nano Letters 18(3): 1557-1563
• Publisher Policy: Reproduced in accordance with the publisher copyright policy