Dynamic stability in phosphorene bilayer with different stacking orders: A first principle study

Phosphorene, a two-dimensional (2D) material obtained by chemical and mechanical exfoliation of its bulk structure named black phosphorus, has recently been of great importance because of its interesting properties. The intercalation of lithium and sodium in phosphorene multilayer can modify the reordering atoms in the structure lead to different properties. In this work we are interested in bilayer phosphorene as the thinnest multilayer structure of phosphorene nanosheets that can provide deep understanding of the interlayer coupling and the stacking dependent phonon vibration modes and the corresponding Raman scattering. Four different stacking orders can be predicted to exist in bilayer phosphorene and needs to be explored experimentally due to the modified properties. Here, we investigate the identification of the four-bilayer stacking sequences (AA, AB, AC, and AD) using Density Functional Theory (DFT), with the GGA and HSE approximations including the van der Waals correction (Grimmes-D3). We identify the variation of the electronic band gap based on the structural difference, interlayer interactions and charge density distribution. A comparison in the phonon vibration modes and Raman spectra between the different stacking orders, show to be useful for monitoring the changes in the bilayer phosphorene structure and identify the rearrangement type of atoms in bilayer phosphorene experimentally. Including temperature effect using AIMD, a description of the structural stability of the bilayer phosphorene structures was reviewed in detail.