Three dimensional atom probe imaging of GaAsSb quantum rings

Beltrán...et al.Unambiguous evidence of ring-shaped self-assembled GaSb nanostructures grown by molecular beam epitaxy is presented on the basis of atom-probe tomography reconstructions and dark field transmission electron microscopy imaging. The GaAs capping process causes a strong segregation of Sb out of the center of GaSb quantum dots, leading to the self-assembled GaAsxSb1−xquantumrings of 20–30 nm in diameter with x∼0.33.This work was supported by the Spanish MCI (projects TEC2008-06756-C03-02/TEC and CONSOLIDER INGENIO2010 CSD2009-00013) and the Junta de Andalucía (PAI research groups TEP-120 and TIC-145; project P08-TEP-03516).Peer reviewe