Investigation of the effect of the doping order in GaN nanowire p-n junctions grown by molecularbeam epitaxy

Omar Saket (1) , Junkang Wang (1) , Nuno Amador-Mendez (1) , Martina Morassi (1) , Arup Kunti (1) , Fabien Bayle (1) , Stéphane Collin (1) , Arnaud Jollivet (1) , Andrey Babichev (2) , Tanbir Sodhi (1) , Jean-Christophe Harmand (1) , François H Julien (1) , Noëlle Gogneau (1) , Maria Tchernycheva (1)

1 C2N - Centre de Nanosciences et de Nanotechnologies
2 ITMO University [Russia]

We analyse the electrical and optical propreties of single GaN nanowire p-n junctions grown by plasma-assisted molecular-beam epitaxy using magnesium and silicon as doping sources. Different junction architectures having either a n-base or a p-base structure are compared using optical and electrical analyses. Electron-beam induced current microscopy of the nanowires shows that in the case of a n-base p-n junction the parasitic radial growth enhanced by the Mg doping leads to a mixed axial-radial behavior with strong wire-to-wire fluctuations of the junction position and shape. By reverting the doping order p-base p-n junctions with a purely axial well-defined structure and a low wire-to-wire dispersion are achieved. The good optical quality of the top n nanowire segment grown on a p-doped stem is preserved. A hole concentration in the p-doped segment exceeding 10 18 cm-3 was extracted from electron beam induced current mapping and photoluminescence analyses. This high concentration is reached without degrading the nanowire morphology.

Mots clés: nanowires; GaN; doping; EBIC; PAMBE

Domaines: Matériaux; Micro et nanotechnologies/Microélectronique; Optique / photonique

Omar Saket, Junkang Wang, Nuno Amador-Mendez, Martina Morassi, Arup Kunti, et al.. Investigation of the effect of the doping order in GaN nanowire p-n junctions grown by molecularbeam epitaxy. Nanotechnology, 2020, ⟨10.1088/1361-6528/abc91a⟩. ⟨hal-03019946⟩