title: Polarity assignment in ZnTe, GaAs, ZnO, and GaN-AlN nanowires from direct dumbbell analysis.
abstract: Aberration corrected scanning transmission electron microscopy (STEM) with high angle annular dark field (HAADF) imaging and the newly developed annular bright field (ABF) imaging are used to define a new guideline for the polarity determination of semiconductor nanowires (NWs) from binary compounds in two extreme cases: (i) when the dumbbell is formed with atoms of similar mass (GaAs) and (ii) in the case where one of the atoms is extremely light (N or O: ZnO and GaN/AlN). The theoretical fundaments of these procedures allow us to overcome the main challenge in the identification of dumbbell polarity. It resides in the separation and identification of the constituent atoms in the dumbbells. The proposed experimental via opens new routes for the fine characterization of nanostructures, e.g., in electronic and optoelectronic fields, where the polarity is crucial for the understanding of their physical properties (optical and electronic) as well as their growth mechanisms.
authors.affiliation: Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, E-08193 Bellaterra, CAT, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: de la Mata
authors.forename: Cesar
authors.initials: C
authors.lastname: Magen
authors.forename: Jaume
authors.initials: J
authors.lastname: Gazquez
authors.forename: Muhammad Iqbal Bakti
authors.initials: MI
authors.lastname: Utama
authors.forename: Martin
authors.initials: M
authors.lastname: Heiss
authors.forename: Sergei
authors.initials: S
authors.lastname: Lopatin
authors.forename: Florian
authors.initials: F
authors.lastname: Furtmayr
authors.forename: Carlos J
authors.initials: CJ
authors.lastname: Fernández-Rojas
authors.forename: Bo
authors.initials: B
authors.lastname: Peng
authors.forename: Joan Ramon
authors.initials: JR
authors.lastname: Morante
authors.forename: Riccardo
authors.initials: R
authors.lastname: Rurali
authors.forename: Martin
authors.initials: M
authors.lastname: Eickhoff
authors.forename: Anna
authors.initials: A
authors.lastname: Fontcuberta i Morral
authors.forename: Qihua
authors.initials: Q
authors.lastname: Xiong
authors.forename: Jordi
authors.initials: J
authors.lastname: Arbiol