Adatom-induced dislocation annihilation in epitaxial silicene

Abstract

The transformation of the stripe domain structure of spontaneously-formed epitaxial silicene on ZrB2 thin films into a single-domain driven by the adsorption of a fraction of a monolayer of silicon was used to investigate how dislocations react and eventually annihilate in a two-dimensional honeycomb structure. The in-situ real time scanning tunneling microscopy monitoring of the evolution of the domain structure after Si deposition revealed the mechanisms leading to the nucleation of a single-domain island into a domain structure through a stepwise reaction of partial dislocations. After its nucleation, the single-domain island extends by the propagation of edge dislocations at its frontiers. The identification of this particular nucleation-propagation formation of dislocation-free silicene sheet provides insights into how crystallographic defects can be healed in two-dimensional materials.

Epitaxial growth and structural properties of silicene and other 2D allotropes of Si

“…151 A mechanism for adatom integration into the initial stripe pattern has been proposed, based on STM measurements performed at RT after deposition of 0.015 ML of Si. 152…”

“…151 A mechanism for adatom integration into the initial stripe pattern has been proposed, based on STM measurements performed at RT aer deposition of 0.015 ML of Si. 152 4.3.2 Si/ZrC. Silicene formation has been reported aer deposition of 1 ML of Si on a ZrC(111)/NbC(111) lm at 800 K. 17 Reection high-energy electron diffraction (RHEED) observations have indicated the formation of a (2 × 2) reconstruction, interpreted as a ð ffiffiffi 3 p  ffiffiffi 3 p Þ silicene reconstruction with a lattice constant of 3.84 Å. Phonon dispersion curves have been obtained from HREELS measurements.…”