α-SiS/black phosphorus van der Waals heterostructure: A promising anode material for sodium-ion batteries

Black phosphorene (BlackP), like α-SiS, is a two-dimensional semiconducting material for advanced microelectronics, with a moderate band gap. Even yet, the epitaxial growth of α-SiS on a fertile substrate has proven to be a formidable obstacle, delaying its widespread production for technological applications. Here based on first-principles approaches we identify that α-SiS (which is not a layered material in bulk form) monolayer could be stabilized either in freestanding form or supported on few layers of a BlackP substrate owing to its isovalency nature and the inherent structural resemblance between the two. Our calculation results demonstrate that α-SiS monolayer is stable on BlackP. Furthermore, the synergistic interfacial effect makes BlackP-like α-SiS and BlackP (α-SiS/BlackP) van der Waals (vdW) heterostructure a viable contender for power-driving sodium-ion batteries owing to relatively high binding strength, ultrafast diffusivity (0.08 eV in region-III), transition from semiconducting to upon sodiation, and substantially high theoretical capacity (329 mAhg−1). Moreover, the α-SiS/BlackP vdW heterostructure possesses high optical absorption strength ∼105 cm−1, and can effectively harvest visible solar radiation. The α-SiS growth on such semiconducting substrates could become a novel platform for next-generation nano-energy technology.