Plane Strain on Band Structures and Photoelectric Properties of 2D Monolayer MoSi2N4

Two-dimensional (2D) monolayer MoSi2N4 has attracted wide attention due to its excellent carrier transport capacity and chemical stability. However, the relationship between its photoelectric properties and applied plane strain has not been thoroughly explored. The effect of plane strain on band structures and photoelectric properties of 2D monolayer MoSi2N4 is revealed by the plane-wave ultrasoft pseudopotentials. The results show that the monolayer MoSi2N4 is an indirect band gap semiconductor. Its top of valance band is dominated by Mo4d orbitals and partly contributed by N2p orbitals, while its bottom of conduction band is mainly contributed by Mo4d orbitals. Under tensile strain, band gap of monolayer MoSi2N4 narrows gradually and effective mass of photogenerated carriers decreases continuously. Under compressive strain, the band gap widens gradually and the effective mass increases slowly. It is worth noting that a compressive strain (epsilon=-2.8%) results in transition form indirect to direct band gap. Optical absorption of monolayer MoSi2N4 exhibits obvious anisotropy, which edge shifts in different degree under the plane strain, effectively expanding the spectral response range of the system and beneficial to the photoelectric properties. These results provide a theoretical guidance for further research on the application of 2D monolayer MoSi2N4 in the field of new tunable nano optoelectronic devices.

Automated summary

This study investigates the effect of plane strain on the band structure and photoelectric properties of two-dimensional MoSi2N4. The results show that strain can modify the band gap and effective mass of photogenerated carriers in MoSi2N4, expanding its potential applications in the field of optoelectronic devices.