title: Improvement of the emission properties from InGaN/GaN dot-in-a-wire nanostructures after treatment in the flowing afterglow of a microwave N₂ plasma.
abstract: Nominally pure GaN nanowires (NWs) and InGaN/GaN dot-in-a-wire heterostructures were exposed to the flowing afterglow of a N2 microwave plasma and characterized by photoluminescence (PL) spectroscopy. While the band-edge emission from GaN NWs and the GaN matrix of the InGaN/GaN NWs strongly decreased due to the creation of non-radiative recombination centers in the near-surface region, the emission from the InGaN dots strongly increased. PL excitation measurements indicate that such an increase cannot be explained by a plasma-induced shift of the GaN absorption edge. It is rather ascribed to the passivation of grown-in defects and dynamic annealing due to the presence of plasma-generated N atoms and N2 metastables without excessive introduction of ion-induced damage.
authors.affiliation: Département de physique, Université de Montréal, Montréal, Québec, H3C 3J7, Canada.
authors.forename: J Afonso
authors.initials: JA
authors.lastname: Ferreira
authors.forename: H P T
authors.initials: HP
authors.lastname: Nguyen
authors.forename: Z
authors.initials: Z
authors.lastname: Mi
authors.forename: R
authors.initials: R
authors.lastname: Leonelli
authors.forename: L
authors.initials: L
authors.lastname: Stafford