Universality of optoelectronic and thermoelectric properties of novel two-dimensional CrSiM2N (M=As, P and N[dbnd]Se, Te) monolayers and their vdWHs with MoTe2

Abstract

In this study, we introduce a novel two-dimensional (2D) monolayer of CrSiM2N (M = As, P and NSe, Te) and explore its electronic properties. For the first time, we employ density functional theory and investigate the electronic and thermoelectric (TE) properties of CrSiM2N (M = As, P and NSe, Te) monolayers. Our calculated phonon band structure confirms that these monolayers are stable and can potentially be synthesized experimentally. The CrSiM2N (M = As, P and NSe, Te) monolayers exhibit an indirect band nature, with the CBM and VBM located at the K and G-points of the first Brillouin zone, respectively. We have also calculated the thermoelectric properties of these systems, which suggest that these monolayers could play a crucial role in enhancing the thermoelectric performance. Furthermore, we investigated the electronic, optical and thermoelectric properties of CrSiM2N (M = As, P and NSe, Te) and MoTe2 van der Waals heterostructures (vdWHs). The electronic band structure exhibits an indirect semiconductor nature, with the conduction band maxima and valence band minima originating from the CrSiM2N (M = As, P and NSe, Te) and MoTe2 monolayers, thereby confirming a type II band alignment. The optical properties indicate that these vdWHs can absorb a broad range of light, from the ultraviolet to the visible and infrared regions. We demonstrated that CrSiM2N (M = As, P and NSe, Te) monolayers exhibit p-type TE behavior, while their vdWHs counterparts exhibit n-type TE behavior.