Near-zero Poisson’s ratio and suppressed mechanical anisotropy in strained black phosphorene/SnSe van der Waals heterostructure: a first-principles study

Black phosphorene (BP) and its analogs have attracted intensive attention due to their unique puckered structures, anisotropic characteristics, and negative Poisson’s ratio. The van der Waals (vdW) heterostructures assembly by stacking different materials show novel physical properties, however, the parent materials do not possess. In this work, the first-principles calculations are performed to study the mechanical properties of the vdW heterostructure. Interestingly, a near-zero Poisson’s ratio v_zx is found in BP/SnSe heterostructure. In addition, compared with the parent materials BP and SnSe with strong in-plane anisotropic mechanical properties, the BP/SnSe heterostructure shows strongly suppressed anisotropy. The results show that the vdW heterostructure has quite different mechanical properties compared with the parent materials, and provides new opportunities for the mechanical applications of the heterostructures.