Strain modulated electronic and optical properties of laterally stitched MoSi2N4/XSi2N4 (X=W, Ti) 2D heterostructures

We used first-principles calculations to investigate the laterally stitched monolayered MoSi2N4/XSi2N4 (X = W, Ti) two-dimensional heterostructures. The structural stability of such heterostructures is confirmed by the phonon spectra exhibiting no imaginary frequencies. From the electronic band structures, the MoSi2N4/WSi2N4- lateral heterostructure (MWLH) shows semiconducting nature with an indirect bandgap of 2.35 eV, while the MoSi2N4/TiSi2N4-lateral heterostructure (MTLH) reveals a bandgap of 0.343 eV. Moreover, the effect of biaxial strain on the electronic and optical properties of MWLH and MTLH is studied, which indicated substantial modifications in their electronic and optical spectra. For instance, the compressive strain in MWLH causes an indirect to direct bandgap transition, while that in MTLH semiconducting to metallic transition. Besides, the absorbance, transmittance and reflectance spectra can effectively be tuned by means of biaxial strain. Our findings provide insights into the strain engineering of electronic and optical features, which could pave the way for future nano-and optoelectronic applications.

Automated summary

By using first-principles calculations, the structural stability and electronic properties of laterally stitched MoSi2N4/XSi2N4 two-dimensional heterostructures were investigated. The results showed that electronic and optical properties can be tuned through biaxial strain.