Tuning electronic properties of MSb (M = C, Si, Ge and Sn) monolayers by strain engineering

In this work, the electronic properties of MSb (M = C, Si, Ge, and Sn) monolayers in the presence of biaxial strain are investigated. The electronic properties such as bandgap, effective mass, deformation potential, and mobility of these monolayers along both zigzag and armchair directions are studied. In these compounds, the hole in the valence band demonstrates higher mobility with respect to the electron. In the following, the effects of the strain on the electronic properties are explored. The bandgap displays a maximum at small tensile strain and decreases at both compressive and tensile strains and a semiconductor-to-metal is also observed. The energy of valleys with respect to strain is studied to find the effective valleys in the conduction and valence bands. In addition, the effective masses of these valleys are calculated. We find that these compounds show a Mexican-hat dispersion at the top of valence for large tensile strain. The Mexican-hat energy and coefficient are explored for various strains.