title: Molecular beam epitaxial growth and characterization of catalyst-free InN/InxGa1-xN core/shell nanowire heterostructures on Si(111) substrates.
abstract: We report on the achievement of, for the first time, InN/InGaN core/shell nanowire heterostructures, which are grown directly on Si(111) substrates by plasma-assisted molecular beam epitaxy. The crystalline quality of the heterostructures is confirmed by transmission electron microscopy, and the elemental mapping through energy dispersive x-ray spectrometry further reveals the presence of an InGaN shell covering the sidewall and top regions of the InN core. The optical characterizations reveal two emission peaks centered at ∼1685 nm and 1845 nm at 5 K, which are related to the emission from the InGaN shell and InN core, respectively. The InN/InGaN core/shell nanoscale heterostructures exhibit a very high internal quantum efficiency of ∼62% at room temperature, which is attributed to the strong carrier confinement provided by the InGaN shell as well as the nearly intrinsic InN core.
authors.affiliation: Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, QC, Canada.
authors.forename: Kai
authors.initials: K
authors.lastname: Cui
authors.forename: Saeed
authors.initials: S
authors.lastname: Fathololoumi
authors.forename: Md
authors.initials: M
authors.lastname: Golam Kibria
authors.forename: Gianluigi A
authors.initials: GA
authors.lastname: Botton
authors.forename: Zetian
authors.initials: Z
authors.lastname: Mi
mesh_terms: D002384:Catalysis; D003460:Crystallization / Q000379:methods*; D005708:Gallium / Q000737:chemistry* / Q000528:radiation effects; D020450:Heavy Ions; D007204:Indium / Q000737:chemistry* / Q000528:radiation effects; D046911:Macromolecular Substances / Q000737:chemistry / Q000528:radiation effects; D008422:Materials Testing; D008968:Molecular Conformation / Q000528:radiation effects; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure*; D010316:Particle Size; D016062:Porosity; D045663:Quantum Dots; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties / Q000528:radiation effects
chemical_list: D046911:Macromolecular Substances; D007204:Indium; C473348:gallium nitride; D005708:Gallium; C513701:indium nitride; D012825:Silicon