Theoretical Study of Carbon Clusters in Silicon Carbide Nanowires

TL;DR

This theoretical study uses first-principles calculations to analyze the formation, stability, and energetics of carbon clusters in silicon carbide nanowires, revealing surface composition effects on defect stability.

Contribution

It provides new insights into the stability and energetics of carbon defects in SiC nanowires based on first-principles calculations, considering different surface terminations.

Findings

Carbon clusters are energetically favored in SiC nanowires.

Surface composition significantly influences defect stability.

Formation energies depend on carbon concentration and nanowire orientation.

Abstract

Using first-principles methods we performed a theoretical study of carbon clusters in silicon carbide nanowires. We examined small clusters with carbon interstitials and antisites in hydrogen-passivated SiC nanowires growth along the [100] and [111] directions. The formation energies of these clusters were calculated as a function of the carbon concentration. We verified that the energetic stability of the carbon defects in SiC nanowires depends strongly on the composition of the nanowire surface: the energetically most favorable configuration in carbon-coated [100] SiC nanowire is not expected to occur in silicon-coated [100] SiC nanowire. The binding energies of some aggregates were also obtained, and they indicate that the formation of carbon clusters in SiC nanowires is energetically favored.