Walther, T. orcid.org/0000-0003-3571-6263 and Krysa, A.B. (2017) Transmission electron microscopy of AlGaAs/GaAs quantum cascade laser structures. Journal of Microscopy , 268 (3). pp. 298-304. ISSN 0022-2720
Abstract
Quantum cascade lasers can be efficient infrared radiation sources and consist of several hundreds of very thin layers arranged in stacks that are repeated periodically. Both the thicknesses of the individual layers as well as the period lengths need to be monitored to high precision. Different transmission electron microscopy methods have been combined to analyse AlGaAs/GaAs quantum cascade laser structures in cross-section. We found a small parabolic variation of the growth rate during deposition, affecting the stack periodicity and a reduced aluminium content of the AlGaAs barriers, whereas their widths as well as those of the GaAs quantum wells agreed with the nominal values within one atomic layer. Growth on an offcut substrate led to facets and steps at the interfaces.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017 The Authors. This is an author produced version of a paper subsequently published in Journal of Microscopy. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Annular dark-field scanning TEM; Z-contrast; composition mapping; high-resolution electron microscopy; quantum cascade laser (QCL); transmission electron microscopy (TEM) |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Electronic and Electrical Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 01 Dec 2017 12:32 |
Last Modified: | 03 Oct 2018 00:38 |
Published Version: | https://doi.org/10.1111/jmi.12655 |
Status: | Published |
Publisher: | Wiley |
Refereed: | Yes |
Identification Number: | 10.1111/jmi.12655 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:124676 |