Role of the wetting layer in the crystallization stage during droplet epitaxy of InAs/GaAs nanostructures

摘要

In this paper, we present the results of experimental study of the role of the wetting layer in the crystallization stage of droplet nanostructures in the lattice-mismatched InAs/GaAs material system. We demonstrate that the thickness of the wetting layer can significantly affect the characteristics of nanostructures formed during crystallization in the arsenic flux. While the surface density of InAs nanostructures does not increase relatively to the initial droplet density obtained at 300 °C, a significant increase of the nanostructure density is observed after crystallization of droplets obtained at 200 °C. This behaviour is attributed to the additional stress-driven Stranski-Krastanov quantum dot formation and confirmed by the 2D-3D transformation of indium layer obtained at 100 °C.