A van der Waals heterostructure of MoS/MoSiN: a first-principles study

Motivated by the successful preparation of MoSi 2 N 4 monolayers in the last year [Y.-L. Hong et al. , Science , 2020, 369 , 670-674], we investigate the structural, electronic and optical properties of the MoS 2 /MoSi 2 N 4 heterostructure (HTS). The phonon dispersion and the binding energy calculations refer to the stability of the HTS. The heterostructure has an indirect bandgap of 1.26 (1.84) eV using PBE (HSE06) which is smaller than the corresponding value of MoSi 2 N 4 and MoS 2 monolayers. We find that the work function of the MoS 2 /MoSi 2 N 4 HTS is smaller than the corresponding value of its individual monolayers. The heterostructure structure can enhance the absorption of light spectra not only in the ultraviolet region but also in the visible region as compared to MoSi 2 N 4 and MoS 2 monolayers. The refractive index behaviour of the HTS can be described as the cumulative effect which is well described in terms of a combination of the individual effects (the refractive index of MoSi 2 N 4 and MoS 2 monolayers). Motivated by the successful preparation of MoSi 2 N 4 monolayers in the last year [Y.-L. Hong et al. , Science , 2020, 369 , 670-674], the structural, electronic and optical properties of MoS 2 /MoSi 2 N 4 heterostructure are investigated.