MSSe-N2CO2 (M = Mo, W and N = Zr, Hf) van der Waals heterostructures; A first principles study

Abstract

Using density functional theory (DFT), we fabricated MSSe-N2CO2 (M = Mo, W and N = Hf, Zr) van der Waals heterostructures (vdWHs). The calculated binding energies, interlayer distance and the AIMD simulations confirm the thermal and dynamic stability of MSSe-N2CO2 vdWHs. Electronic band structure reveals that, model-I of MoSSe-Zr2Co2(WSSe-Zr2CO2) and MoSSe-Hf2CO2(WSSe-Hf2CO2) vdWHs are indirect type-I(-II) bandgap semiconductors. In case of model-II of MSSe-N2CO2 vdWH, the valance band maxima (VBM) and conduction band minima (CBM) lies from different monolayers, hence confirm type-II band alignment. Furthermore, in these vdWHs, transition of electrons between two different constituents (layers) of the vdWHs, greatly facilitates effective separation for photogenerated charge carriers. Absorption spectra are also calculated to understand the optical behavior of these systems. Favorable band edge positions of MSSe-N2CO2 vdWHs also facilitate water splitting at pH = 0 in photocatalysis. Our simulated design of MSSe-N2CO2 vdWHs is promising for future optoelectronic, and photocatalytic device applications.