Type I band alignment in GaAs 81 Sb 19 /GaAs core-shell nanowires

Tao Xu , Mengjie Wei , Pierre Capiod (1) , Adrian Díaz Álvarez , Xiang-Lei Han , David Troadec (1) , Jean-Philippe Nys , Maxime Berthe (1) , Isabelle Lefebvre (2) , Gilles Patriarche (3) , S.R. Plissard (4) , Philippe Caroff (1) , Philipp Ebert , B. Grandidier (1)

1 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
2 IBMM - Institut des Biomolécules Max Mousseron [Pôle Chimie Balard]
3 LPN - Laboratoire de photonique et de nanostructures
4 LAAS-MPN - Équipe Matériaux et Procédés pour la Nanoélectronique

The composition and band gap of the shell that formed during the growth of axial GaAs/GaAs81Sb19/ GaAs heterostructure nanowires have been investigated by transmission electron microscopy combined with energy dispersion spectroscopy, scanning tunneling spectroscopy, and density functional theory calculations. On the GaAs81Sb19 intermediate segment, the shell is found to be free of Sb (pure GaAs shell) and transparent to the tunneling electrons, despite the (110) biaxial strain that affects its band gap. As a result, a direct measurement of the core band gap allows the quantitative determination of the band offset between the GaAs81Sb19 core and the GaAs shell and identifies it as a type I band alignment.

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Physique Quantique [quant-ph]; Cristallographie; Matériaux

Tao Xu, Mengjie Wei, Pierre Capiod, Adrian Díaz Álvarez, Xiang-Lei Han, et al.. Type I band alignment in GaAs 81 Sb 19 /GaAs core-shell nanowires. Applied Physics Letters, 2015, 107 (11), pp.112102. ⟨10.1063/1.4930991⟩. ⟨hal-01713079⟩