Bandgap engineering in Si1−xCx by substitutional doping: First-principle calculations

Abstract

In this paper, a novel approach is presented for the first time to increase the energy gap of Si-based material by doping carbon atoms into Si-based material structures. The structural electronic properties and mechanical properties of [Formula: see text] ([Formula: see text], 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4) are investigated using a first-principles calculation method. Bandgaps of the [Formula: see text] shells were found to have, respectively, quadratic relationships with the Carbon content [Formula: see text]. Meanwhile, the electronic bandgap of Si-based material can be increased by 0.334 eV due to the carbon substitutions. The optimal structure is [Formula: see text] and the elastic constants and phono calculations reveal that [Formula: see text] is mechanically and dynamically stable. Finally, two different heavy doped [Formula: see text] have been investigated and the results indicate that the [Formula: see text]-type and [Formula: see text]-type doped [Formula: see text] do produce shallow levels. This study can be a theoretical guidance to improve the bandgap of Si-based semiconductors. In addition, [Formula: see text] show superior bandgap and material properties enabling [Formula: see text] power device operation at higher temperatures, voltages than current Si-based power semiconductor device.