Temperature behaviour of the average size of nanoparticle lattices co-deposited with an amorphous matrix. Analysis of Ge + Al2O3 and Ni + Al2O3 thin films

J Phys Condens Matter. 2017 Nov 1;29(43):435301. doi: 10.1088/1361-648X/aa7f3c.

Abstract

We theoretically interpret the thermal behaviour of the average radius versus substrate temperature of regular quantum dot/nanocluster arrays formed by sputtering semiconductor/metal atoms with oxide molecules. The analysis relies on a continuum theory for amorphous films with given surface quantities, perturbed by a nanoparticle lattice. An account of the basic thermodynamic contributions is given in terms of force-flux phenomenological coefficients of each phase (Ge, Ni, Al2O3). Average radii turn out to be expressible by a characteristic length scale and a dimensionless parameter, which mainly depend upon temperature through diffusion lengths, film pressures and finite-size corrections to interfacial tensions. The numerical agreement is good in both Ge ([Formula: see text]) and Ni ([Formula: see text]) lattices grown at temperatures [Formula: see text]800 K, despite the lower temperature behaviour of quantum dots seeming to suggest further driving forces taking part in such processes.