Strain-engineering the electronic properties and anisotropy of GeSe monolayers.

As a new two-dimensional (2D) material, GeSe has attracted significant attention recently due to its distinctive in-plane anisotropic properties originated from the in-plane anisotropic crystal structure, high air stability and excellent performance in polarization-sensitive photodetection. However, no systematic study of the strain effect on the electronic properties and anisotropy of GeSe has been reported, restricting the relevant applications such as mechanical-electronic devices. Here we investigate the change of the electronic properties and anisotropy of GeSe monolayer under strains along and directions through first-principle calculations. The electronic band structure and effective mass of charge carriers are highly sensitive to the strain. Notably, through appropriate or directional strain, the anisotropy of the hole effective mass can even be rotated by 90°. These plentiful strain-engineering properties of GeSe give it many opportunities in novel mechanical-electronic applications.