title: Semiconductor-oxide heterostructured nanowires using postgrowth oxidation.
abstract: Semiconductor-oxide heterointerfaces have several electron volts high-charge carrier potential barriers, which may enable devices utilizing quantum confinement at room temperature. While a single heterointerface is easily formed by oxide deposition on a crystalline semiconductor, as in MOS transistors, the amorphous structure of most oxides inhibits epitaxy of a second semiconductor layer. Here, we overcome this limitation by separating epitaxy from oxidation, using postgrowth oxidation of AlP segments to create axial and core-shell semiconductor-oxide heterostructured nanowires. Complete epitaxial AlP-InP nanowire structures were first grown in an oxygen-free environment. Subsequent exposure to air converted the AlP segments into amorphous aluminum oxide segments, leaving isolated InP segments in an oxide matrix. InP quantum dots formed on the nanowire sidewalls exhibit room temperature photoluminescence with small line widths (down to 15 meV) and high intensity. This optical performance, together with the control of heterostructure segment length, diameter, and position, opens up for optoelectrical applications at room temperature.
authors.affiliation: Solid State Physics, Lund University , Box 118, S-221 00, Lund, Sweden.
authors.forename: Jesper
authors.initials: J
authors.lastname: Wallentin
authors.forename: Martin
authors.initials: M
authors.lastname: Ek
authors.forename: Neimantas
authors.initials: N
authors.lastname: Vainorious
authors.forename: Kilian
authors.initials: K
authors.lastname: Mergenthaler
authors.forename: Lars
authors.initials: L
authors.lastname: Samuelson
authors.forename: Mats-Erik
authors.initials: ME
authors.lastname: Pistol
authors.forename: L
authors.initials: L
authors.lastname: Reine Wallenberg
authors.forename: Magnus T
authors.initials: MT
authors.lastname: Borgström
mesh_terms: D000535:Aluminum / Q000737:chemistry; D007204:Indium / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry*; D053770:Nanowires / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D010758:Phosphorus / Q000737:chemistry; D012666:Semiconductors
chemical_list: D010087:Oxides; D007204:Indium; D010758:Phosphorus; D000535:Aluminum; D010100:Oxygen