Negative Poissons ratios in few-layer orthorhombic arsenic from first-principles calculations

A material exhibiting a negative Poissons ratio is always one of the leading topics in materials science, which is due to the potential applications in those special areas such as defence and medicine. In this letter, we demonstrate a new material, few-layer orthorhombic arsenic, also possesses the negative Poissons ratio. For monolayer arsenic, the negative Poissons ratio is predicted to be around -0.09, originated from the hinge-like structure within the single layer of arsenic. When the layer increases, the negative Poissons ratio becomes more negative and finally approaches the limit at four-layer, which is very close to the bulks value of -0.12. The underlying mechanism is proposed for this layer-dependent negative Poissons ratio, where the internal bond lengths as well as the normal Poissons ratio within layer play a key role. The study like ours sheds new light on the physics of negative Poissons ratio in those hinge-like nano-materials.

Manifestation of unexpected semiconducting properties in few-layer orthorhombic arsenene

In this express, we demonstrate few-layer orthorhombic arsenene is an ideal semiconductor. Due to the layer stacking, multilayer arsenenes always behave as intrinsic direct bandgap semiconductors with gap values of around 1 eV. In addition, these bandgaps can be further tuned in its nanoribbons. Based on the so-called acoustic phonon limited approach, the carrier mobilities are predicted to approach as high as several thousand square centimeters per volt-second and simultaneously exhibit high directional anisotropy. All these make few-layer arsenene promising for device applications in semiconducting industry.