Stability of MoS$_{\mathrm{2(1-x)}}$Se$_{\mathrm{2x}}$ alloy: insight from first-principles calculations

Two-dimensional transition metal dichalcogenide (TMD) alloy is an interesting class of TMD because the ability to tune continuously its bandgap opens many new possibilities for basic studies, device concepts, and fabrication of novel heterostructures. We will present phonon dispersions of MoS$_{\mathrm{2(1-x)}}$Se$_{\mathrm{2x}}$ alloy calculated using Density Functional Perturbation Theory (DFPT). The dispersions do not show any existence of instability modes for various Se concentrations ($x)$, attesting the stability of this TMD alloy. We will, in addition, show electronic and optical properties, including Raman spectra, of MoS$_{\mathrm{2(1-x)}}$Se$_{\mathrm{2x}}$ alloy as a function of Se concentrations and their comparison with available experimental data.