Plastic relaxation of the misfit stress in core-shell semi-conducting nanowires can lead to structural defects, detrimental to applications. Core-shell Zn0.7Mg0.3O/ZnO quantum well heterostructures were deposited on ZnO nanowires. Strain along the a and c axes of the wurtzite structure was relaxed through the glide of dislocation half-loops from the free surfaces, within pyramidal and prismatic planes. Some half-loops were closed up in the barriers to accommodate the misfit at two consecutive interfaces of the quantum well stack. Dislocations were also observed within the nanowire core: contrary to two-dimensional structures, both the core and the shell can be plastically relaxed.

Strain Relaxation by Dislocation Glide in ZnO/ZnMgO Core-Shell Nanowires. G.Perillat-Merceroz, R.Thierry, P.H.Jouneau, P.Ferret, G.Feuillet: Applied Physics Letters, 2012, 100[17], 173102