Phosphorene is a two dimensional material whose direct semiconducting band-gap, high carrier mobility and sensitivity to strain make it promising for applications.
We report a series of quantum Monte Carlo (QMC) calculations for bulk black phosphorus and related few-layer phosphorene, which elucidate the nature of theforces that bind these systems and provide benchmark data for the energetics of these systems. We find a significant charge redistribution due to the interaction between electrons on adjacent layers.Comparison to density functional theory (DFT) calculations indicate not only wide variability even among different vdW corrected functionals, but the failure of these functionals to capture the trendof reorganization predicted by QMC. The delicate interplay of steric and dispersive forces between layers indicate that few-layer phosphorene presents an unexpected challenge for the development ofvdW corrected DFT.
L. Shulenburger, A. D. Baczewski, Z. Zhu, J. Guan, and D. Tomanek. "The Nature of the Interlayer Interaction in Bulk and Few-Layer Phosphorus", Nano Letters 15 8170 (2015). https://doi.org/10.1021/acs.nanolett.5b03615