Dislocation loops in solid and hollow semiconductor and metal nanoheterostructures

Abstract

This paper has considered theoretical models of misfit stress relaxation in solid and hollow “core-shell” composite nanoparticles of semiconductors and metals due to the formation of dislocations of two types: circular prismatic dislocation loops (PDLs) lying at the interface in the equatorial nanoparticle plane and rectangular PDLs growing from the free surface of such a nanoparticle and extended along its surface. Critical conditions of nucleation of such loops have been compared. It has been shown that either a coherent (dislocation-free) state of the nanoparticle or its relaxed state with a circular PDL at the interface is favorable in the case of a relatively small lattice misfit between the core and shell materials. For large misfits, the coherent state is unfavorable. In this case, as the shell thickness increases, it can be expected that, first, rectangular PDLs will appear, then circular PDLs will be formed while retaining rectangular PDLs, and then rectangular PDLs will gradually grow and transform to circular PDLs.