Adatom incorporation and step crossing at the edges of 2D nanoislands

TL;DR

This paper analyzes how adatoms incorporate into the edges of 2D nanoislands, deriving step permeability and incorporation coefficients, and explores conditions affecting step permeability during nanoisland growth.

Contribution

It introduces a detailed analysis of adatom incorporation and step crossing at nanoisland edges, including derivation of key coefficients for various growth scenarios.

Findings

Permeability can occur even with fast edge migration if kink formation is delayed.

Alternating rough and straight segments affect permeability depending on adatom transport.

Step structure influences adatom incorporation and crossing during nanoisland growth.

Abstract

Adatom incorporation into the ``faceted'' steps bordering the 2D nanoislands is analyzed. The step permeability and incorporation coefficients are derived for some typical growth situations. It is shown that the step consisting of equivalent straight segments can be permeable even in the case of fast egde migration if there exist factors delaying creation of new kinks. The step consisting of alternating rough and straight segments may be permeable if there is no adatom transport between neighboring segments through the corner diffusion.