Electronic and optical properties of SnX2(X = S, Se)-InSe van der Waal's heterostructures from first-principle calculations

In this work from first-principles simulations we investigate bilayer van der Waal's heterostructures (vdWh) of emerging 2-dimensional optical materials SnS2 and SnSe2 with monolayer InSe. With density functional theory calculations, we study the structural, electronic, optical and carrier transport properties of the SnX2 (X = S, Se)-InSe vdWh. Calculations show SnX2-InSe in its most stable stacking form (named AB-1) to be a material with a small (0.6-0.7 eV) indirect band-gap. The bilayer vdWh shows broad spectrum optical response, with number of peaks in the infra-red to visible region. In terms of carrier transport properties, asymmetry in conductance was observed with respect to the transport direction and electron and hole transmission. The findings are promising from the viewpoint of nanoelectronics and photonics.