We construct a class of two-dimensional (2D) phosphorus allotropes by assembling a previously proposed ultrathin metastable phosphorus nanotube into planar structures in different stacking orientations. Based on first-principles methods, the structures, stabilities, and fundamental electronic properties of these allotropes are systematically investigated. Our results show that these 2D van der Waals phosphorene allotropes possess remarkable stabilities due to the strong intertube van der Waals interactions, which cause an energy release of about $30–70\mathrm{meV}/\mathrm{atom}$, depending on their stacking details. Most of them are confirmed to be energetically more favorable than the experimentally viable $\alpha \text{−}\mathrm{P}$ and $\beta \text{−}\mathrm{P}$. Three of them, showing a relatively higher probability of being synthesized in the future, are further confirmed to be dynamically stable semiconductors with strain-tunable band gaps and intrinsic piezoelectricity, which may have potential applications in nanosized sensors, piezotronics, and energy harvesting in portable electronic nanodevices.

• Received 16 February 2017
• Revised 13 February 2018

DOI:https://doi.org/10.1103/PhysRevApplied.9.044032