Focusing on the liquid role in the vapour liquid solid growth mechanism

In this work we dive into key questions regarding the wetting of a nanoscale droplet which provides fundamental understanding of Vapor-Liquid-Solid growth mode of nanowires. This understanding is important to performreproducible NW fabrication and allow their industrial implementation. Our method relies on the continuous interplay between experimental efforts and theoreticalmodeling in order to combine computational prediction power with reality. In particular the main aspects analysed are the stability of the calalyst-NW system and the dynamics of nucleation at the nanoscale. These phenomena are of fundamental importance not only for the synthesis of nanostructures but also in other areas such as colloidal chemistry and bioengineering. We proceed by focusing on three main aspects of NW preparation: first stages of NW’s growth, catalyst-NW system stability and nucleation dynamics. At first we focus on the preparation of arrays of semiconductor nanowires with the target to optimize the vertical yield thanks to the engineering of the wetting behavior of the catalytic droplets at the initial stages of growth. Secondly we investigate the wetting behavior of droplets constrained on top of nanowires and/or cylindrical pillars. In such conditions, droplet volume and constraint geometry are the key factors for determining the most stable configuration of the droplet and thus the direction of further steps of growth. In the last chapters, we analyzemore exotic nanowires and thus the wetting behavior of droplets is observed on new geometrical constraints. Beyond droplet’s morphological investigation, we consider the consequences of the presence of the liquid phase on the nucleation dynamics, in particular at the triple-phase line, under the assumption of crystal anisotropy of the nucleating phase and the presence of stretching capillary forces.