Mechanisms of Stranski-Krastanov Growth

TL;DR

This paper presents a kinetic Monte Carlo model that replicates the Stranski-Krastanov growth mode, capturing key experimental features such as the wetting layer stability, critical thickness, and temperature effects in heteroepitaxial growth.

Contribution

A novel KMC model that accurately simulates SK growth, including wetting layer stability, critical thickness, and temperature dependence, aligning with experimental observations.

Findings

Wetting layer is stable due to entropy effects.

Critical thickness decreases with increasing temperature.

Wetting layer thickness increases with temperature.

Abstract

Stranski-Krastanov (SK) growth is reported experimentally as the growth mode that is responsible for the transition to three dimensional islands in heteroepitaxial growth. A kinetic Monte Carlo (KMC) model is proposed that can replicate many of the experimentally observed features of this growth mode. Simulations reveal that this model effectively captures the SK transition and subsequent growth. Annealing simulations demonstrate that the wetting layer formed during SK growth is stable, with entropy playing a key role in its stability. It is shown that this model also captures the apparent critical thickness that tends to occur at higher deposition rates and for alloy films (where intermixing is significant). This work shows that the wetting layer thickness increases with increasing temperature, whereas the apparent critical thickness decreases with increasing temperature. Both of which are in agreement with experiments.