MBE growth of van der Waals epitaxy using graphene buffer layer

SnS van der Waals epitaxies (vdWEs) were deposited by MBE on graphene buffer layer (GBL). Photo-absorption measurements indicate an indirect bandgap of ~1 eV and a direct bandgap of ~1.25 eV with high absorption coefficient, α, of >104 cm-1 at 1.5 eV. Significant improvements in both the grain size and the rocking curve FWHM were observed compared to films deposited without the GBL. Hole mobility of ~81 cm2V-1s-1 was observed for the films deposited on GBL. Such improvements are attributed to the high tolerances in the lattice mismatch between the SnS vdWE and the substrate when a GBL is used.