The effect of changing stacking patterns on electronic and optical properties of black phosphorus by strain:A computational study

Abstract

Abstract The synergy effect on structural properties, electronic properties, and optical properties when changing strain and the number of layers at the same time of 2D black phosphorus (BP) are calculated in this paper by using first-principles calculations. The results show that with the number of the layer increased, the band-gap shows a decreasing trend, whereas the absorption edge shows a trend of red-shift. When we put different in-layer biaxial strain from −10% compressive strain (a/a0 = 90%) to 10% tensile strain (a/a0 = 110%) on all few-layer BP layers, the electronic, optical and structural properties change. In terms of electronic property, few-layer BP shows an increasing trend of the band-gap, and at the same time, a distinct change of chemical bond has been observed. As for the optical property, an anisotropic variation of the absorption and reflectivity occurs. And for the structural property, there is a noticeable regular anisotropic change of the stacking order. In our opinion, the increasing number of layers affects band splitting around the Γ point and entire BZ, which leads to the decrease of the gap. The changing of the layer from 5 L to 1L and the strain from −10% compressive strain to 10% tensile strain affect the stacking order and the change of near-band-states of few-layer BP, which further impacts the band-gap, chemical bond and its transition from metal to semiconductor of BP. Besides, the strain effect leads to the anisotropic change of the structure, which further results in the anisotropic change in the optical properties of the few-layer BP. This study implies that we can alter the function of the few-layer material by setting up the suitable strain and the number of the layer in the future.