Two dimensional allotropes of arsenene with a wide range of high and anisotropic carrier mobility.

Considering the rapid development of experimental techniques for fabricating 2D materials in recent years, various monolayers are expected to be experimentally realized in the near future. Motivated by the recent research activities focused on the honeycomb arsenene monolayers, the stability and carrier mobility of non-honeycomb and porous allotropic arsenene are determined using first principles calculations. In addition to five honeycomb structures of arsenene, a total of eight other structures are considered in this study. An extensive analysis comprising energetics, phonon spectra and mechanical properties confirms that these structures are energetically and dynamically stable. All these structures are semiconductors with a broad range of band gaps varying from ∼1 eV to ∼2.5 eV. Significantly, these monolayer allotropes possess anisotropic carrier mobilities as high as several hundred cm2 V-1 s-1 which is comparable with well-known 2D materials such as black phosphorene and monolayer MoS2. Combining such broad band gaps and superior carrier mobilities, these monolayer allotropes can be promising candidates for the superior performance of the next generation nanoscale devices. We further explore these monolayer allotropes for photocatalytic water splitting and find that arsenene monolayers have potential for usage in visible light driven photocatalytic water splitting.