title: Plastic and elastic strain fields in GaAs/Si core-shell nanowires.
abstract: Thanks to their unique morphology, nanowires have enabled integration of materials in a way that was not possible before with thin film technology. In turn, this opens new avenues for applications in the areas of energy harvesting, electronics, and optoelectronics. This is particularly true for axial heterostructures, while core-shell systems are limited by the appearance of strain-induced dislocations. Even more challenging is the detection and understanding of these defects. We combine geometrical phase analysis with finite element strain simulations to quantify and determine the origin of the lattice distortion in core-shell nanowire structures. Such combination provides a powerful insight in the origin and characteristics of edge dislocations in such systems and quantifies their impact with the strain field map. We apply the method to heterostructures presenting single and mixed crystalline phase. Mixing crystalline phases along a nanowire turns out to be beneficial for reducing strain in mismatched core-shell structures.
authors.affiliation: Laboratoire des Matériaux Semiconducteurs (LMSC)and ‡Institute of Microengineering (IMT), Photovoltaics and Thin Film Electronics Laboratory, École Polytechnique Fédérale de Lausanne (EPFL) , 1015 Lausanne, Switzerland.
authors.forename: Sònia
authors.initials: S
authors.lastname: Conesa-Boj
authors.forename: Francesca
authors.initials: F
authors.lastname: Boioli
authors.forename: Eleonora
authors.initials: E
authors.lastname: Russo-Averchi
authors.forename: Sylvain
authors.initials: S
authors.lastname: Dunand
authors.forename: Martin
authors.initials: M
authors.lastname: Heiss
authors.forename: Daniel
authors.initials: D
authors.lastname: Rüffer
authors.forename: Nicolas
authors.initials: N
authors.lastname: Wyrsch
authors.forename: Christophe
authors.initials: C
authors.lastname: Ballif
authors.forename: Leo
authors.initials: L
authors.lastname: Miglio
authors.forename: Anna
authors.initials: A
authors.lastname: Fontcuberta i Morral
mesh_terms: D001152:Arsenicals / Q000737:chemistry*; D003460:Crystallization; D004548:Elasticity; D020342:Finite Element Analysis; D005708:Gallium / Q000737:chemistry*; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D012666:Semiconductors; D012825:Silicon / Q000737:chemistry*
chemical_list: D001152:Arsenicals; C043055:gallium arsenide; D005708:Gallium; D012825:Silicon