American Journal of Applied Sciences

Photoelectrochemical Corrosion of GaN/AlGaN-Based p-n Structures

Alexander Usikov, Heikki Helava, Alexey Nikiforov, Michael Puzyk, Boris Papchenko and Yuri Makarov

DOI : 10.3844/ajassp.2016.845.852

American Journal of Applied Sciences

Volume 13, Issue 7

Pages 845-852

Abstract

Direct water photoelectrolysis using III-N materials is a promising way for hydrogen production. GaN/AlGaN based p-n structures were used as working electrodes in a photoelectrochemical process to investigate the material etching (corrosion). The structures were grown on sapphire substrates by chloride Hydride Vapor Phase Epitaxy (HVPE). First, the etching process occurs near vertically via channels associated with defects in the structure and penetrates deep into the structure. Then, the process involves etching of the n-type AlGaN barrier and n-GaN active layer in lateral direction resulting in formation of voids and cavities. The lateral etching is due to net positive charges at the AlGaN/GaN interfaces arising because of spontaneous and piezoelectric polarization in the structure and positively charged ionized donors in the space charge region of the p-n junction.

Copyright

© 2016 Alexander Usikov, Heikki Helava, Alexey Nikiforov, Michael Puzyk, Boris Papchenko and Yuri Makarov. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.