Investigation of structural, electronic and transport properties of Silicene on Graphene heterostructure by ab-initio calculations

In this work, the structural and transport properties of the heterostructure composed of silicene on graphene are investigated using the Quantum Espresso and BoltzTraP. The heterostructure of silicene and graphene
$(\text{Si}_{5}\mathrm{C}_{11})$
were examined initially, the binding energy
$(E_{\mathrm{b}})$
is found to be around 31.4 meV/atom and the formation energy
$(E_{\text{form}})$
of the heterostructure is found to be around -4.592 eV/atom. The
$E_{\text{form}}$
is found to be 0.763 eV larger than the monolayer graphene and 2.145 eV lower than the monolayer silicene. From the band structure it has been observed that, the heterostructure of silicene and graphene
$(\text{Si}_{5}\mathrm{C}_{11})$
has a weak interband interactions whereas the Van der Waal interaction is dominant at the interlayer contact between the graphene sheet and the silicene sheet. The bands crossing around Fermi level (Ef), implies that
$\text{Si}_{5}\mathrm{C}_{11}$
exhibits semi-metallic characteristics. The transport properties of the heterostructure shows that the electrical conductivity and Seebeck coefficient has good thermoelectric properties.