Droplet Epitaxy of Nanostructures

The droplet epitaxy is an innovative growth method, performed in the molecular beam epitaxy environment, for the fabrication of quantum nanostructures with highly designable shapes and complex morphologies. Droplet epitaxy is based on the split of the deposition of III and V column elements at controlled temperatures and fluxes. The first step of droplet epitaxy is the formation of nanoscale metal atoms reservoirs on the growth surface in forms of nanometer-size droplets with small-size dispersion. The metallic droplets on the surface will constitute the group III localized sources from which the nanostructures will evolve. Second, and more relevant for the nanostructure shape control, is the supply of group V elements at different temperatures and fluxes. This allows for the possibility finely to control, through flux and temperature, the transformation kinetics of the metal droplets in to III–V nanocrystals, thus leading to `the formation of nanostructures with complex and controlled shapes. In this chapter, droplet epitaxy founding concepts will be introduced. A detailed review of the droplet epitaxy fabrication procedure of III–V nanostructures, as well of the main droplet epitaxy achievements, will be presented.