DFT study of the electronic and vibrational properties of silicene/stanene heterobilayer

Abstract In the recent years, many studies have been showed that bilayer and heterobilayer silicene (or stanene) might offer properties superior to those of monolayer. Nevertheless, only very few have been synthesized. Using first-principles calculations, we study the structural, vibrational, and electronic properties of silicene/stanene heterobilayer. We show that the structure of silicene/stanene can be stable, where the dynamical stability is demonstrated by the phonon dispersion curve. The interlayer binding energy is found to be typical of van der Waals bonding. Our LDA, GGA, and vdW results show that the band-gaps are direct in a range between 70 and 160 meV, which are promising candidates for diverse device applications.