Effect of point defects on the electronic density states of SnC nanosheets: First-principles calculations

Abstract

In this work, we investigated the electronic and structural properties of various defects including single Sn and C vacancies, double vacancy of the Sn and C atoms, anti-sites, position exchange and the Stone–Wales (SW) defects in SnC nanosheets by using density-functional theory (DFT). We found that various vacancy defects in the SnC monolayer can change the electronic and structural properties. Our results show that the SnC is an indirect band gap compound, with the band gap of 2.10eV. The system turns into metal for both structure of the single Sn and C vacancies. However, for the double vacancy contained Sn and C atoms, the structure remains semiconductor with the direct band gap of 0.37eV at the G point. We also found that for anti-site defects, the structure remains semiconductor and for the exchange defect, the structure becomes indirect semiconductor with the K-G point and the band gap of 0.74eV. Finally, the structure of SW defect remains semiconductor with the direct band gap at K point with band gap of 0.54eV.