V. Vonk, D. Pontoni, M. Cremers, A. Kerkenaar, A.A.C. Bode, W. Szweryn, G. Nowak, A.E.F. de Jong, H. Dosch, E. Vlieg,
Observation of ultrathin precursor film formation during Ge−Si liquid-phase epitaxy from an undersaturated solution,
Langmuir 33 (2017) 814-819

Abstract

Our in situ X-ray study shows that a silicon substrate in contact with an undersaturated In(Ge) solution is wetted by an approximately 1 nm thin germanium film, which does not grow any thicker. The results can be understood by the use of thickness-dependent correlated interfacial energies. This near-equilibrium heterogeneous interface structure marks the initial stage of crystal growth before the formation of bulk material, which can only form under conditions of supersaturation. This finding uncovers a fundamental aspect of the thermodynamics at solid–liquid interfaces relevant for understanding the transition from equilibrium to supersaturation and is of importance for nanoscale solution growth methods