Strain relaxation in epitaxial GaAs/Si (0 0 1) nanostructures. Issue 31 (2nd November 2017)

• Record Type: Journal Article
• Authors: Kozak, Roksolana; Prieto, Ivan; Arroyo Rojas Dasilva, Yadira; Erni, Rolf; Skibitzki, Oliver; Capellini, Giovanni; Schroeder, Thomas; von Känel, Hans; Rossell, Marta D.
• Is Part Of: Philosophical magazine. Volume 97:Issue 31(2017)
• Page Start: 2845
• Page End: 2857
• Publication Date: 2017-11-02
• Subjects: Dislocations -- stacking faults -- twins -- strain relaxation -- HAADF-STEM -- GaAs -- Si nanostructures; Condensed matter -- Periodicals; Physics -- Periodicals; Matière condensée -- Périodiques; Physique -- Périodiques; 530.41
• DOI: 10.1080/14786435.2017.1355117
• Languages: English
• ISSNs: 1478-6435

Abstract

Abstract: Crystal defects, present in ~100 nm GaAs nanocrystals grown by metal organic vapour phase epitaxy on top of (0 0 1)-oriented Si nanotips (with a tip opening 50–90 nm), have been studied by means of high-resolution aberration-corrected high-angle annular dark-field scanning transmission electron microscopy. The role of 60° perfect, 30° and 90° Shockley partial misfit dislocations (MDs) in the plastic strain relaxation of GaAs on Si is discussed. Formation conditions of stair-rod dislocations and coherent twin boundaries in the GaAs nanocrystals are explained. Also, although stacking faults are commonly observed, we show here that synthesis of GaAs nanocrystals with a minimum number of these defects is possible. On the other hand, from the number of MDs, we have to conclude that the GaAs nanoparticles are fully relaxed plastically, such that for the present tip sizes no substrate compliance can be observed.