title: High Yield of GaAs Nanowire Arrays on Si Mediated by the Pinning and Contact Angle of Ga.
abstract: GaAs nanowire arrays on silicon offer great perspectives in the optoelectronics and solar cell industry. To fulfill this potential, gold-free growth in predetermined positions should be achieved. Ga-assisted growth of GaAs nanowires in the form of array has been shown to be challenging and difficult to reproduce. In this work, we provide some of the key elements for obtaining a high yield of GaAs nanowires on patterned Si in a reproducible way: contact angle and pinning of the Ga droplet inside the apertures achieved by the modification of the surface properties of the nanoscale areas exposed to growth. As an example, an amorphous silicon layer between the crystalline substrate and the oxide mask results in a contact angle around 90°, leading to a high yield of vertical nanowires. Another example for tuning the contact angle is anticipated, native oxide with controlled thickness. This work opens new perspectives for the rational and reproducible growth of GaAs nanowire arrays on silicon.
authors.affiliation: †Laboratoire des Matériaux Semiconducteurs, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Russo-Averchi
authors.affiliation: †Laboratoire des Matériaux Semiconducteurs, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
authors.forename: Jelena
authors.initials: J
authors.lastname: Vukajlovic Plestina
authors.affiliation: †Laboratoire des Matériaux Semiconducteurs, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
authors.forename: Gözde
authors.initials: G
authors.lastname: Tütüncüoglu
authors.affiliation: †Laboratoire des Matériaux Semiconducteurs, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
authors.forename: Federico
authors.initials: F
authors.lastname: Matteini
authors.affiliation: †Laboratoire des Matériaux Semiconducteurs, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
authors.forename: Anna
authors.initials: A
authors.lastname: Dalmau-Mallorquí
authors.affiliation: ‡Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193 Bellaterra, Catalonia, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: de la Mata
authors.affiliation: †Laboratoire des Matériaux Semiconducteurs, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Rüffer
authors.affiliation: †Laboratoire des Matériaux Semiconducteurs, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
authors.forename: Heidi A
authors.initials: HA
authors.lastname: Potts
authors.affiliation: ‡Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193 Bellaterra, Catalonia, Spain.|§ICREA and Institut Català de Nanociència i Nanotecnologia (ICN2), Campus UAB, 08193 Bellaterra, Catalonia, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Arbiol
authors.affiliation: †Laboratoire des Matériaux Semiconducteurs, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
authors.forename: Sonia
authors.initials: S
authors.lastname: Conesa-Boj
authors.affiliation: †Laboratoire des Matériaux Semiconducteurs, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
authors.forename: Anna
authors.initials: A
authors.lastname: Fontcuberta i Morral
keywords: Ga-assisted GaAs nanowires; III−V on silicon; arrays; molecular beam epitaxy; vertical nanowires