LAUSR

Hybrid two-dimensional (2D) materials composed of carbon- and germanium-doped silicene monolayers, denoted as Si1–xCx, Si1–xGex, and Si1–2xCxGex (0 ≤ x ≤ 1), were investigated by first-principles calculations. Their structural features can be understood on the basis of Vegard’s law. The lattice parameters were found to correlate well with the arithmetic mean of the percentage doping of the individual constituents. The electronic band gap showed an interesting bell-shaped behavior for Si1–xCx with respect to doping, wherein Eg increased from 0 (for x = 0) to a maximum (for x = 0.5) and eventually decreased again to 0 (for x = 1). Clearly controlled carbon doping of the silicene monolayer was found to open up the band gaps and also provides a means of harvesting solar energy for semiconductor and photovoltaic applications. In addition to pristine monolayer silicene, we also investigated the effects of Ca(II)-intercalated multilayer silicene/germanene as available in the van der Waals mineral phases of CaSi2...