Dynamics and ordering of the nucleationless island formation in heteroepitaxy

TL;DR

This paper investigates how strained islands form and evolve during heteroepitaxial growth, revealing flux-dependent dynamics, island ordering, and spatial correlations through a continuum model.

Contribution

It introduces a continuum model that captures flux-tuned nonlinear regimes and island ordering in heteroepitaxial growth, highlighting new morphological behaviors.

Findings

Flux controls transition from annealing to ripening regimes.

High flux leads to ordered island arrangements with ridge-like clusters.

Island density increases steadily with flux.

Abstract

We study the morphological evolution of strained islands in growing crystal films by use of a continuum description including wetting, elasticity and deposition flux. Wetting breaks translational invariance, allowing the flux to tune different nonlinear regimes. Increasing the flux, we find first an annealing-like dynamics, then a slower but non-conventional ripening followed by a steady regime, while the island density continuously increases. The islands develop spatial correlations and ordering with a narrow two-peaked distance distribution and ridge-like clusters of islands for high flux.