Hexagonal and pentagonal shapes of self-catalyzed one-dimensional GaAs nanostructures: Shape dependence of the phase evolutions

摘要

Hexagonal and pentagonal shapes of one-dimensional (1-D) nanostructures were observed at the growth of GaAs by molecular beam epitaxy method without catalyst aid. We report on the phase evolution dependence on the shapes of 1-D GaAs nanostructures. The hexagonal-shaped nanostructures showed a transition region composed of twin boundaries and stacking faults during the phase transition from a zinc-blende (ZB) structure to a wurtzite (WZ) structure. On the other hand, the pentagonal-shaped nanostructures appeared to have an abrupt transition from a ZB structure to a WZ structure and to be elongated along (112) directions of a ZB structure.