1College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061 2College of Mechanical and Electronic Engineering, Nanyang Normal University, Nanyang 473061 3College of Material Science and Engineering, Guilin University of Technology, Guilin 541004
Abstract：By means of the particle-swarm optimization method and density functional theory calculations, the lowest-energy structure of SnAs is determined to be a bilayer stacking system and the atoms on top of each other are of the same types. Using the hybrid functional of Heyd–Scuseria–Ernzerhof, SnAs is calculated to be a semiconductor with an indirect band gap of 1.71 eV, which decreases to 1.42 eV with the increase of the bi-axial tensile stress up to 2%, corresponding to the ideal value of 1.40 eV for potential photovoltaic applications. Based on the deformation potential theory, the two-dimensional (2D) SnAs has high electron motilities along $x$ and $y$ directions ($1.63\times10^{3}$ cm$^{2}$V$^{-1}$s$^{-1}$). Our calculated results suggest that SnAs can be viewed as a new type of 2D materials for applications in optoelectronics and nanoelectronic devices.
2018, Vol. 35 
