Tuning the electronic structure and Schottky barrier by NbX2 contact to MXY (M=Mo, W; (X/=Y)--S, Se, Te) monolayer

Electronic structure, contact type (Schottky contact) and height of the Schottky barrier at the interface of NbX2 and MXY (M = Mo, W; (X/=Y)--S, Se, Te) metal -semiconductor (MS) contact in the form of NbX2-MXY van der Waals heterostructure (vdWH) are investigated by first -principles calculations. Thermal and dynamical stabilities of these systems confirmed via Ab-initio molecular dynamics (AIMD) simulation, binding energies and phonon spectrum calculations. Electronic band structures, show that NbX2-MXY MS contact in model -I and -II are metal and seem to be simple sum of NbX2 and MXY monolayers due to the weak vdW interaction. The quite small effective mass in specific cases of the NbX2-MXY MS vdWH in model -I and -II, exhibit high carrier mobility, hence can be considered a potential candidate for future high-speed nanoelectronic applications. Furthermore, electrostatic potential, charge density difference and bader charges are also evaluated for detail understanding of the variation in the work function and transfer of charges among the layer, while fabricating NbX2-MXY MS contact in the form of vdWHs. At the equilibrium interlayer distance, the NbX2-MXY MS contact forms a p -type (n -type in specific cases) Schottky contact.