Theoretical investigation on the structural stability of GaAs nanowires with two different types of facets

摘要

The relative stability between the wurtzite and zinc blende structures in GaAs nanowires with 111/1100 facets and those of 110 / 1120 facets is systematically investigated using our empirical interatomic potential calculations and first-principles calculations. Our calculations clarify that the wurtzite structure is stabilized over entire diameters range for nanowires with 111/1100 facets. In contrast, for nanowires consisting of 110/1120 facets, the zinc blende structure is favorable for diameters larger than 29 nm. This is because the surface energy difference between 110 and 1120 surfaces is quite small compared to that between 1 1 1 and 1100 surfaces. The calculated results imply that the stability of nanowire side facets is a quite important factor determining the crystal structure.