TY  - JOUR
AU  - Usikov, Alexander 
AU  - Helava, Heikki 
AU  - Nikiforov, Alexey 
AU  - Puzyk, Michael 
AU  - Papchenko, Boris 
AU  - Makarov, Yuri 
PY  - 2016
TI  - Photoelectrochemical Corrosion of GaN/AlGaN-Based p-n Structures
JF  - American Journal of Applied Sciences
VL  - 13
IS  - 7
DO  - 10.3844/ajassp.2016.845.852
UR  - https://thescipub.com/abstract/ajassp.2016.845.852
AB  - 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.