Band gap controlling of doped bulk silicon carbide structure under the influence of tensile stress: DFT

Abstract

We investigated the effect of tensile stress on a bulk pristine silicon carbide (SiC) and Titanium-doped silicon carbide in two different substitutional sites employing first-principle calculations. The changes in electronic properties have been monitored after the substitution of a silicon atom or a carbon atom in SiC crystal with titanium atom. The simulation results show a clear band gap closing in all structures with symmetric behavior observed in the case of titaniumin in the silicon substitutional site and asymmetric behavior in the case of titanium in the carbon substitutional site. Furthermore, the changes in the Fermi energy, valence bands, and conduction bands have been studied. Calculations reveal a systematic up-shift in the Fermi energy as a consequence of the applied stress, and a systematic down-shift in the Fermi energy in response to the applied tensile strain.