Monolayer, Bilayer, and Heterostructures of Green Phosphorene for Water Splitting and Photovoltaics

Abstract

We report the results of density functional theory-based calculations on monolayer and bilayer green phosphorene and their heterostructures with MoSe 2 . Both monolayer and bilayer green phosphorene are direct band gap semiconductors and possess anisotropic carrier mobility as high as 10 4 cm 2 /V/s. In bilayers, the pressure of about 9 GPa induces the semiconductor-metal transition. Moreover, the band gap depends strongly on the thickness of the films and the external electric field. By employing strain engineering under suitable solution conditions, monolayer and AC-stacked bilayer green phosphorene offer the band edge alignments which can be used for water splitting. The upper limit of the power conversion efficiencies for monolayer and AB- and AC-stacked bilayer green phosphorene heterostructures with MoSe 2 is calculated to be 18-21%. Our results show the possibility of green phosphorene to be used as a photocatalytic and photovoltaic material in energy-related applications. - 2018 American Chemical Society.