Electro/mechanical mutable properties of black phosphorene by electric field and strain engineering

Abstract

Phosphorene a two dimensional (2D) arrangement of black phosphorus atoms has greatly manifested extraordinary properties. In this work we investigated the electronic and mechanical properties of a deformed structural (i.e. modified two characteristic angles) single-layer black phosphorus using tight-binding (TB) Hamiltonian and Green’s function approach, where a planar and a most puckered structure have been created by modifying the angle between two nearest neighboring P–P bond from two sublayers. Moreover, by using density functional theory (DFT), we show that the applied strain in the x, y axes and electric field can be used to tune the electronic properties of black phosphorene. We also provide a comparison of phonon vibrational modes of planar and puckered phosphorene to compare their structure stability. It was found that by structural deformation such as modifying the angle between two nearest neighboring P–P bond from two sublayers, consequently having a planar and a most puckered structure, no change can be seen for the effective masses along the y (zigzag) direction, but totally affected along the x (armchair) direction leading to heavier electrons and holes. Furthermore, 2D phosphorene exhibits different stiffness for applied strain in the x, y direction. Such rich variety of electronic, mechanical and structural transformations provides 2D phosphorene as a unique material for fundamental physics studies and applicable in nanoelectronic and nanophotonics devices.