Lattice Boltzmann simulation of metal-induced crystallization of amorphous semiconductor films

摘要

Interface interactions in metal-semiconductor couples are a subject of current interest in electronics, optics, catalysis, energy, and biotechnology. The process of interaction is unknown in many aspects and might be accompanied by a mass transfer on large scales as in the case of the metal-induced crystallization of amorphous semiconductor films. We simulated the kinetics of interaction of liquid Au nanoparticles on the amorphous Ge substrate by means of lattice Boltzmann method for the first time. We supposed that (i) crystalline Ge randomly nucleated and grew under the Au nanoparticle, and (ii) amorphous Ge has a higher surface wettability with Au than the crystalline one. The advancement of the Au nanoparticle on the Ge substrate has been observed and the conditions of activation and maintenance of the movement have been analyzed. Nucleation and growth rates of the crystalline phase, as well as the difference in wetting conditions, were the primary factors that initiated and controlled the nanoparticle movement. The simulations results have been compared with the experimental high-resolution TEM observations.