Island Sliding Barriers: A first-principles metric for determining remote epitaxy viability

TL;DR

This paper introduces a first-principles metric based on island sliding barriers to predict the viability of remote epitaxy, offering a kinetic perspective over previous electrostatic potential metrics.

Contribution

It proposes the island sliding barrier as a new, more effective criterion for assessing remote epitaxy compatibility between substrate and film.

Findings

Sliding barrier correlates with remote epitaxy success

Electrostatic potential metrics are insufficient

Kinetics of island migration influence remote epitaxy

Abstract

Remote epitaxy, where a 2D van der Waals material (usually graphene) is inserted on top of the substrate before film epitaxy, has emerged as a promising path for growing electronics with lower defect rates and less stringent lattice matching requirements. The exact mechanism behind remote epitaxy has not been definitively shown, however, and it is not obvious when examining a new substrate-film pair whether they would be compatible with the remote epitaxy process. In this paper, we use first principles calculations to test several different mechanisms for determining whether a given substrate-film pair will successfully be grown with remote epitaxy. We find that previously calculated metrics such as electrostatic potential do not hold sufficient explanatory power. We find that the sliding barrier of small islands on the surface when the atomic positions are allowed to optimize provides the most rigorous criteria for whether a given substrate-film pair is remote epitaxy active. This indicates that remote epitaxy is likely a phenomenon related to the kinetics and ease of island migration on the graphene surface.